101
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Gut microbiome and brain functional connectivity in infants-a preliminary study focusing on the amygdala. Psychopharmacology (Berl) 2019; 236:1641-1651. [PMID: 30604186 PMCID: PMC6599471 DOI: 10.1007/s00213-018-5161-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 12/21/2018] [Indexed: 12/26/2022]
Abstract
Recently, there has been a surge of interest in the possibility that microbial communities inhabiting the human gut could affect cognitive development and increase risk for mental illness via the "microbiome-gut-brain axis." Infancy likely represents a critical period for the establishment of these relationships, as it is the most dynamic stage of postnatal brain development and a key period in the maturation of the microbiome. Indeed, recent reports indicate that characteristics of the infant gut microbiome are associated with both temperament and cognitive performance. The neural circuits underlying these relationships have not yet been delineated. To address this gap, resting-state fMRI scans were acquired from 39 1-year-old human infants who had provided fecal samples for identification and relative quantification of bacterial taxa. Measures of alpha diversity were generated and tested for associations with measures of functional connectivity. Primary analyses focused on the amygdala as manipulation of the gut microbiota in animal models alters the structure and neurochemistry of this brain region. Secondary analyses explored functional connectivity of nine canonical resting-state functional networks. Alpha diversity was significantly associated with functional connectivity between the amygdala and thalamus and between the anterior cingulate cortex and anterior insula. These regions play an important role in processing/responding to threat. Alpha diversity was also associated with functional connectivity between the supplementary motor area (SMA, representing the sensorimotor network) and the inferior parietal lobule (IPL). Importantly, SMA-IPL connectivity also related to cognitive outcomes at 2 years of age, suggesting a potential pathway linking gut microbiome diversity and cognitive outcomes during infancy. These results provide exciting new insights into the gut-brain axis during early human development and should stimulate further studies into whether microbiome-associated changes in brain circuitry influence later risk for psychopathology.
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102
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Differential gene expression in the mesocorticolimbic system of innately high- and low-impulsive rats. Behav Brain Res 2019; 364:193-204. [DOI: 10.1016/j.bbr.2019.01.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 12/12/2018] [Accepted: 01/12/2019] [Indexed: 02/02/2023]
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103
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Sanders A, Rackers H, Kimmel M. A role for the microbiome in mother-infant interaction and perinatal depression. Int Rev Psychiatry 2019; 31:280-294. [PMID: 30784334 DOI: 10.1080/09540261.2018.1548431] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Perinatal depression is a significant public health problem, due to its negative impact on maternal well-being and long-term adverse effects for children. Mother-infant interaction and maternal responsiveness and sensitivity are a hypothesized mechanism by which perinatal depression effects child development, and increasing research in the microbiota-gut-brain axis may provide a new avenue of investigation. There is limited efficacy for treatment of perinatal depression for improving the mother-infant relationship and child outcomes. The maternal microbiota may be the basis of child outcomes through foetal programming and sharing of microbes between mother and infant. There is evidence that less diversity of the intestinal microbial community is associated with neuropsychiatric disorders, including depression and anxiety in mothers and offspring. Assessing the maternal and child's microbial communities may be an important missing component in mother-infant attachment-based therapies during treatment of perinatal depression. Probiotics and prebiotics require further research as additions to mother-infant interventions. Further research may enable identification of bacterial genes that indicate specific pathways that could be targeted to improve outcomes for mother and child.
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Affiliation(s)
- Amanda Sanders
- a Department of Psychiatry , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
| | - Hannah Rackers
- a Department of Psychiatry , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
| | - Mary Kimmel
- a Department of Psychiatry , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
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104
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Chu D, Li L, Jiang Y, Tan J, Ji J, Zhang Y, Jin N, Liu F. Excess Folic Acid Supplementation Before and During Pregnancy and Lactation Activates Fos Gene Expression and Alters Behaviors in Male Mouse Offspring. Front Neurosci 2019; 13:313. [PMID: 31024236 PMCID: PMC6460239 DOI: 10.3389/fnins.2019.00313] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 03/19/2019] [Indexed: 12/28/2022] Open
Abstract
Periconceptional folic acid (FA) supplementation is recommended to prevent neural tube defects and other birth defects. After 20 years mandate food fortification with FA, serum concentration of folate and unmetabolized FA increased significantly in the North American population. But whether excess FA intake impairs neurodevelopment and behavior is still controversial. Here, we treated mice with approximately 2.5-fold (moderate dose of FA, MFA) or 10-fold (high dose of FA, HFA) the dietary requirement of FA 1 week before mating and throughout pregnancy and lactation, and examined behaviors in adult male offspring using open field test, three-chamber sociability and social novelty test, elevated plus maze, rotarod and Morris water maze. We found that early life MFA supplementation increased long-term body weight gain in adults, elevated anxiety-like behavior, and impaired social preference, motor learning and spatial learning ability without modifying motor ability and spatial memory. In contrast, HFA supplementation only induced mild behavioral abnormality. RNA sequencing revealed that FA supplementation altered the expression of brain genes at weaning, among which Fos and related genes were significantly up-regulated in MFA mice compared with control and HFA mice. Quantitative real time-PCR (qRT-PCR) and western blots confirmed the increase of these genes. Our results suggested that FA supplementation during early life stage affected gene expression in weaning mice, and exhibited long-term impairments in adult behaviors in a dose-sensitive manner.
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Affiliation(s)
- Dandan Chu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Longfei Li
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yanli Jiang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Jianxin Tan
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Jie Ji
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yongli Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Nana Jin
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Fei Liu
- Department of Neurochemistry, Inge Grundke-Iqbal Research Floor, New York State Institute for Basic Research in Developmental Disabilities, New York, NY, United States
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105
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Kentner AC, Cryan JF, Brummelte S. Resilience priming: Translational models for understanding resiliency and adaptation to early life adversity. Dev Psychobiol 2019; 61:350-375. [PMID: 30311210 PMCID: PMC6447439 DOI: 10.1002/dev.21775] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/22/2018] [Accepted: 07/10/2018] [Indexed: 12/20/2022]
Abstract
Despite the increasing attention to early life adversity and its long-term consequences on health, behavior, and the etiology of neurodevelopmental disorders, our understanding of the adaptations and interventions that promote resiliency and rescue against such insults are underexplored. Specifically, investigations of the perinatal period often focus on negative events/outcomes. In contrast, positive experiences (i.e. enrichment/parental care//healthy nutrition) favorably influence development of the nervous and endocrine systems. Moreover, some stressors result in adaptations and demonstrations of later-life resiliency. This review explores the underlying mechanisms of neuroplasticity that follow some of these early life experiences and translates them into ideas for interventions in pediatric settings. The emerging role of the gut microbiome in mediating stress susceptibility is also discussed. Since many negative outcomes of early experiences are known, it is time to identify mechanisms and mediators that promote resiliency against them. These range from enrichment, quality parental care, dietary interventions and those that target the gut microbiota.
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Affiliation(s)
- Amanda C. Kentner
- School of Arts & Sciences, Massachusetts College of Pharmacy and Health Sciences, 179 Longwood Ave, Boston, MA 02115,
| | - John F. Cryan
- Dept. Anatomy & Neuroscience & APC Microbiome Institute, University College Cork, College Rd., Cork, Ireland,
| | - Susanne Brummelte
- Department of Psychology, Wayne State University, 5057 Woodward Ave, Detroit, MI 48202,
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106
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Maldonado-Ruiz R, Garza-Ocañas L, Camacho A. Inflammatory domains modulate autism spectrum disorder susceptibility during maternal nutritional programming. Neurochem Int 2019; 126:109-117. [PMID: 30880046 DOI: 10.1016/j.neuint.2019.03.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/30/2019] [Accepted: 03/11/2019] [Indexed: 12/21/2022]
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental disease which involves functional and structural defects in selective central nervous system (CNS) regions harming capability to process and respond to external stimuli. In addition to genetic background, etiological causes of ASD have not been fully clarified. Maternal immune activation (MIA) during pregnancy have been proposed as a potential etiological cause leading to aberrant synaptic pruning and microglia-mediated neurogenesis impairment. Several clinical studies suggest that pro-inflammatory profile during maternal obesity associates with a higher risk of having a child with autism. In this context, the effect of maternal programing by high fat diet overconsumption during pregnancy sets a pro-inflammatory profile partly dependent on an epigenetic program of immunity which promotes brain micro and macrostructural abnormalities in the offspring that might last through adulthood accompanied by phenotypic changes in ASD subjects. Of note, maternal programming of inflammation during development seems to integrate the CNS and peripheral immune system cross-talk which arrays central inflammatory domains coordinating ASD behavior. In this review, we discuss basic and clinical studies regarding the effects of obesity-induced MIA on peripheral immune cells and microglia priming and their relationship with brain structural alterations in ASD models. Also, we show supportive evidence stating the role of maternal programming on epigenetic gene activation in immune cells of ASD subjects. We suggest that maternal programming by hypercaloric diets during development sets a central and peripheral immune cross-talk which potentially might modulate brain macro and microstructural defects leading to autism susceptibility.
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Affiliation(s)
- Roger Maldonado-Ruiz
- Universidad Autónoma de Nuevo Leon, Facultad de Medicina, Biochemistry Department, Mexico; Universidad Autónoma de Nuevo Leon, Centro de Investigación y Desarrollo en Ciencias de la Salud, Neurometabolism Unit, Mexico
| | - Lourdes Garza-Ocañas
- Universidad Autonoma de Nuevo Leon, Facultad de Medicina, Department of Pharmacology, Mexico
| | - Alberto Camacho
- Universidad Autónoma de Nuevo Leon, Facultad de Medicina, Biochemistry Department, Mexico; Universidad Autónoma de Nuevo Leon, Centro de Investigación y Desarrollo en Ciencias de la Salud, Neurometabolism Unit, Mexico.
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107
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Autism Spectrum Disorders and the Gut Microbiota. Nutrients 2019; 11:nu11030521. [PMID: 30823414 PMCID: PMC6471505 DOI: 10.3390/nu11030521] [Citation(s) in RCA: 212] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 02/08/2023] Open
Abstract
In recent years, there has been an emerging interest in the possible role of the gut microbiota as a co-factor in the development of autism spectrum disorders (ASDs), as many studies have highlighted the bidirectional communication between the gut and brain (the so-called “gut-brain axis”). Accumulating evidence has shown a link between alterations in the composition of the gut microbiota and both gastrointestinal and neurobehavioural symptoms in children with ASD. The aim of this narrative review was to analyse the current knowledge about dysbiosis and gastrointestinal (GI) disorders in ASD and assess the current evidence for the role of probiotics and other non-pharmacological approaches in the treatment of children with ASD. Analysis of the literature showed that gut dysbiosis in ASD has been widely demonstrated; however, there is no single distinctive profile of the composition of the microbiota in people with ASD. Gut dysbiosis could contribute to the low-grade systemic inflammatory state reported in patients with GI comorbidities. The administration of probiotics (mostly a mixture of Bifidobacteria, Streptococci and Lactobacilli) is the most promising treatment for neurobehavioural symptoms and bowel dysfunction, but clinical trials are still limited and heterogeneous. Well-designed, randomized, placebo-controlled clinical trials are required to validate the effectiveness of probiotics in the treatment of ASD and to identify the appropriate strains, dose, and timing of treatment.
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108
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Leclercq S, Stärkel P, Delzenne NM, de Timary P. The gut microbiota: A new target in the management of alcohol dependence? Alcohol 2019; 74:105-111. [PMID: 30031625 DOI: 10.1016/j.alcohol.2018.03.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 03/15/2018] [Accepted: 03/15/2018] [Indexed: 02/06/2023]
Abstract
The gastrointestinal tract is the natural habitat for a huge community of microorganisms, comprising bacteria, viruses, fungi and yeast. This microbial ecosystem codevelops with the host throughout life and is subject to a complex interplay that depends on multiple factors including host genetics, nutrition, life-style, stress, diseases and antibiotics use. The gut microbiota, that refers to intestinal bacteria, has profound influence on the host immune system, metabolism and nervous system. Indeed, intestinal bacteria supply the host with essential nutrients such as vitamins, metabolize bile acids and undigested compounds, defend against pathogen invasion, participate to the development of the intestinal architecture and the intestinal immune system and play an important role in the maintenance of the gut barrier function. More recently, the gut microbiota has been shown to influence brain functions, such as myelin synthesis, the blood-brain barrier permeability and neuroinflammatory responses but also mood and behavior. The cross-talk between microbes and the host implicates a vast array of signaling pathways that involve many different classes of molecules like metabolites produced by the bacteria from dietary or endogenous sources of carbohydrates and proteins (i.e. short-chain fatty acids (SCFAs), indole), neurotransmitters and inflammatory cytokines. This review will focus on the involvement of the gut microbiota in the pathophysiological aspects of alcohol dependence related to the gut barrier function, liver damage and psychological disturbances. We will also discuss the possibility to create new and realistic humanized animal models of alcohol dependence by the use of fecal transplantation.
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Affiliation(s)
- Sophie Leclercq
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium; Louvain Drug Research Institute, Metabolism and Nutrition Research Group, Université Catholique de Louvain, Brussels, Belgium.
| | - Peter Stärkel
- Institute of Experimental and Clinical Research, Laboratory of Hepato-Gastroenterology, Université Catholique de Louvain, Brussels, Belgium; Department of Hepato-Gastroenterology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Nathalie M Delzenne
- Louvain Drug Research Institute, Metabolism and Nutrition Research Group, Université Catholique de Louvain, Brussels, Belgium
| | - Philippe de Timary
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium; Department of Adult Psychiatry, Cliniques Universitaires Saint-Luc, Brussels, Belgium
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109
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Langgartner D, Lowry CA, Reber SO. Old Friends, immunoregulation, and stress resilience. Pflugers Arch 2019; 471:237-269. [PMID: 30386921 PMCID: PMC6334733 DOI: 10.1007/s00424-018-2228-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/03/2018] [Accepted: 10/22/2018] [Indexed: 02/07/2023]
Abstract
There is a considerable body of evidence indicating that chronic adverse experience, especially chronic psychosocial stress/trauma, represents a major risk factor for the development of many somatic and affective disorders, including inflammatory bowel disease (IBD) and posttraumatic stress disorder (PTSD). However, the mechanisms underlying the development of chronic stress-associated disorders are still in large part unknown, and current treatment and prevention strategies lack efficacy and reliability. A greater understanding of mechanisms involved in the development and persistence of chronic stress-induced disorders may lead to novel approaches to prevention and treatment of these disorders. In this review, we provide evidence indicating that increases in immune (re-)activity and inflammation, potentially promoted by a reduced exposure to immunoregulatory microorganisms ("Old Friends") in today's modern society, may be causal factors in mediating the vulnerability to development and persistence of stress-related pathologies. Moreover, we discuss strategies to increase immunoregulatory processes and attenuate inflammation, as for instance contact with immunoregulatory Old Friends, which appears to be a promising strategy to promote stress resilience and to prevent/treat chronic stress-related disorders.
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Affiliation(s)
- Dominik Langgartner
- Laboratory for Molecular Psychosomatics, Department of Psychosomatic Medicine and Psychotherapy, University Ulm, Albert-Einstein-Allee 23, 89081, Ulm, Germany
| | - Christopher A Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA
- Department of Physical Medicine & Rehabilitation and Center for Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
- Veterans Health Administration, Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Denver Veterans Affairs Medical Center (VAMC), Denver, CO, 80220, USA
- Military and Veteran Microbiome Consortium for Research and Education (MVM-CoRE), Denver, CO, 80220, USA
| | - Stefan O Reber
- Laboratory for Molecular Psychosomatics, Department of Psychosomatic Medicine and Psychotherapy, University Ulm, Albert-Einstein-Allee 23, 89081, Ulm, Germany.
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110
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D'Agata AL, Wu J, Welandawe MKV, Dutra SVO, Kane B, Groer MW. Effects of early life NICU stress on the developing gut microbiome. Dev Psychobiol 2019; 61:650-660. [PMID: 30697700 DOI: 10.1002/dev.21826] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 02/06/2023]
Abstract
Succession of gut microbial community structure for newborns is highly influenced by early life factors. Many preterm infants cared for in the NICU are exposed to parent-infant separation, stress, and pain from medical care procedures. The purpose of the study was to investigate the impact of early life stress on the trajectory of gut microbial structure. Stool samples from very preterm infants were collected weekly for 6 weeks. NICU stress exposure data were collected daily for 6 weeks. V4 region of the 16S rRNA gene was amplified by PCR and sequenced. Zero-inflated beta regression model with random effects was used to assess the impact of stress on gut microbiome trajectories. Week of sampling was significant for Escherichia, Staphylococcus, Enterococcus, Bifidobacterium, Proteus, Streptococcus, Clostridium butyricum, and Clostridium perfringens. Antibiotic usage was significant for Proteus, Citrobacter, and C. perfringens. Gender was significant for Proteus. Stress exposure occurring 1 and 2 weeks prior to sampling had a significant effect on Proteus and Veillonella. NICU stress exposure had a significant effect on Proteus and Veillonella. An overall dominance of Gammaproteobacteria was found. Findings suggest early life NICU stress may significantly influence the developing gut microbiome, which is important to NICU practice and future microbiome research.
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Affiliation(s)
- Amy L D'Agata
- College of Nursing, University of Rhode Island, Kingston, Rhode Island.,College of Nursing, University of South Florida, Tampa, Florida
| | - Jing Wu
- Computer Science and Statistics, University of Rhode Island, Kingston, Rhode Island
| | | | - Samia V O Dutra
- College of Nursing, University of South Florida, Tampa, Florida
| | - Bradley Kane
- College of Nursing, University of South Florida, Tampa, Florida
| | - Maureen W Groer
- College of Nursing, University of South Florida, Tampa, Florida
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111
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Decoding the role of the microbiome on amygdala function and social behaviour. Neuropsychopharmacology 2019; 44:233-234. [PMID: 30341410 PMCID: PMC6235835 DOI: 10.1038/s41386-018-0233-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 09/23/2018] [Indexed: 12/26/2022]
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112
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Warner BB. The contribution of the gut microbiome to neurodevelopment and neuropsychiatric disorders. Pediatr Res 2019; 85:216-224. [PMID: 30283047 DOI: 10.1038/s41390-018-0191-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/17/2018] [Accepted: 08/29/2018] [Indexed: 02/06/2023]
Abstract
Bidirectional communication between the gut and brain is well recognized, with data now accruing for a specific role of the gut microbiota in that link, referred to as the microbiome-gut-brain axis. This review will discuss the emerging role of the gut microbiota in brain development and behavior. Animal studies have clearly demonstrated effects of the gut microbiota on gene expression and neurochemical metabolism impacting behavior and performance. Based on these changes, a modulating role of the gut microbiota has been demonstrated for a variety of neuropsychiatric disorders, including depression, anxiety, and movement including Parkinson's, and importantly for the pediatric population autism. Critical developmental windows that influence early behavioral outcomes have been identified that include both the prenatal environment and early postnatal colonization periods. The clearest data regarding the role of the gut microbiota on neurodevelopment and psychiatric disorders is from animal studies; however, human data have begun to emerge, including an association between early colonization patterns and cognition. The importance of understanding the contribution of the gut microbiota to the development and functioning of the nervous system lies in the potential to intervene using novel microbial-based approaches to treating neurologic conditions. While pathways of communication between the gut and brain are well established, the gut microbiome is a new component of this axis. The way in which organisms that live in the gut influence the central nervous system (CNS) and host behavior is likely to be multifactorial in origin. This includes immunologic, endocrine, and metabolic mechanisms, all of which are pathways used for other microbial-host interactions. Germ-free (GF) mice are an important model system for understanding the impact of gut microbes on development and function of the nervous system. Alternative animal model systems have further clarified the role of the gut microbiota, including antibiotic treatment, fecal transplantation, and selective gut colonization with specific microbial organisms. Recently, researchers have started to examine the human host as well. This review will examine the components of the CNS potentially influenced by the gut microbiota, and the mechanisms mediating these effects. Links between gut microbial colonization patterns and host behavior relevant to a pediatric population will be examined, highlighting important developmental windows in utero or early in development.
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Affiliation(s)
- Barbara B Warner
- Department of Pediatrics, School of Medicine, Washington University in St Louis, Saint Louis, MO, USA.
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113
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Liu F, Horton-Sparks K, Hull V, Li RW, Martínez-Cerdeño V. The valproic acid rat model of autism presents with gut bacterial dysbiosis similar to that in human autism. Mol Autism 2018; 9:61. [PMID: 30555669 PMCID: PMC6288876 DOI: 10.1186/s13229-018-0251-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 11/26/2018] [Indexed: 02/07/2023] Open
Abstract
Background Gut microbiota has the capacity to impact the regular function of the brain, which can in turn affect the composition of microbiota. Autism spectrum disorder (ASD) patients suffer from gastrointestinal problems and experience changes in gut microbiota; however, it is not yet clear whether the change in the microbiota associated with ASD is a cause or a consequence of the disease. Methods We have investigated the species richness and microbial composition in a valproic acid (VPA)-induced rat model autism. Fecal samples from the rectum were collected at necropsy, microbial total DNA was extracted, 16 rRNA genes sequenced using Illumina, and the global microbial co-occurrence network was constructed using a random matrix theory-based pipeline. Collected rat microbiome data were compared to available data derived from cases of autism. Results We found that VPA administration during pregnancy reduced fecal microbial richness, changed the gut microbial composition, and altered the metabolite potential of the fecal microbial community in a pattern similar to that seen in patients with ASD. However, the global network property and network composition as well as microbial co-occurrence patterns were largely preserved in the offspring of rats exposed to prenatal administration of VPA. Conclusions Our data on the microbiota of the VPA rat model of autism indicate that this model, in addition to behaviorally and anatomically mimicking the autistic brain as previously shown, also mimics the microbiome features of autism, making it one of the best-suited rodent models for the study of autism and ASD.
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Affiliation(s)
- Fang Liu
- College of Food Science and Engineering, Ocean University of China, Qingdao, China
| | - Kayla Horton-Sparks
- Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, 2504 Stockton Blvd, Sacramento, CA 95817 USA
| | - Vanessa Hull
- Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, 2504 Stockton Blvd, Sacramento, CA 95817 USA
| | - Robert W. Li
- United States Department of Agriculture, Agriculture Research Service (USDA-ARS), Animal Genomics and Improvement Laboratory, Beltsville, MD USA
| | - Verónica Martínez-Cerdeño
- Institute for Pediatric Regenerative Medicine and Shriners Hospitals for Children Northern California, 2504 Stockton Blvd, Sacramento, CA 95817 USA
- Department of Pathology and Laboratory Medicine, UC Davis School of Medicine, Sacramento, CA USA
- MIND Institute, Sacramento, CA USA
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114
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Dehhaghi M, Kazemi Shariat Panahi H, Guillemin GJ. Microorganisms' Footprint in Neurodegenerative Diseases. Front Cell Neurosci 2018; 12:466. [PMID: 30564101 PMCID: PMC6288487 DOI: 10.3389/fncel.2018.00466] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/16/2018] [Indexed: 01/08/2023] Open
Abstract
Advancement of science has gifted the human a longer life; however, as neuron cells do not regenerate, the number of people with neurodegeneration disorders rises with population aging. Neurodegeneration diseases occur as a result of neuronal cells loss caused by environmental factors, genetic mutations, proteopathies and other cellular dysfunctions. The negative direct or indirect contributions of various microorganisms in onset or severity of some neurodegeneration disorders and interaction between human immune system and pathogenic microorganisms has been portrayed in this review article. This association may explain the early onset of neurodegeneration disorders in some individuals, which can be traced through detailed study of health background of these individuals for infection with any microbial disease with neuropathogenic microorganisms (bacteria, fungi, viruses). A better understanding and recognition of the relation between microorganisms and neurodegeneration disorders may help researchers in development of novel remedies to avoid, postpone, or make neurodegeneration disorders less severe.
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Affiliation(s)
- Mona Dehhaghi
- Neuroinflammation Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.,Department of Microbial Biotechnology, School of Biology and Centre of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran
| | - Hamed Kazemi Shariat Panahi
- Neuroinflammation Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.,Department of Microbial Biotechnology, School of Biology and Centre of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran, Iran
| | - Gilles J Guillemin
- Neuroinflammation Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
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115
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Grosser K, Ramasamy P, Amirabad AD, Schulz MH, Gasparoni G, Simon M, Schrallhammer M. More than the "Killer Trait": Infection with the Bacterial Endosymbiont Caedibacter taeniospiralis Causes Transcriptomic Modulation in Paramecium Host. Genome Biol Evol 2018; 10:646-656. [PMID: 29390087 PMCID: PMC5814942 DOI: 10.1093/gbe/evy024] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2018] [Indexed: 12/13/2022] Open
Abstract
Endosymbiosis is a widespread phenomenon and hosts of bacterial endosymbionts can be found all-over the eukaryotic tree of life. Likely, this evolutionary success is connected to the altered phenotype arising from a symbiotic association. The potential variety of symbiont’s contributions to new characteristics or abilities of host organisms are largely unstudied. Addressing this aspect, we focused on an obligate bacterial endosymbiont that confers an intraspecific killer phenotype to its host. The symbiosis between Paramecium tetraurelia and Caedibacter taeniospiralis, living in the host’s cytoplasm, enables the infected paramecia to release Caedibacter symbionts, which can simultaneously produce a peculiar protein structure and a toxin. The ingestion of bacteria that harbor both components leads to the death of symbiont-free congeners. Thus, the symbiosis provides Caedibacter-infected cells a competitive advantage, the “killer trait.” We characterized the adaptive gene expression patterns in symbiont-harboring Paramecium as a second symbiosis-derived aspect next to the killer phenotype. Comparative transcriptomics of infected P. tetraurelia and genetically identical symbiont-free cells confirmed altered gene expression in the symbiont-bearing line. Our results show up-regulation of specific metabolic and heat shock genes whereas down-regulated genes were involved in signaling pathways and cell cycle regulation. Functional analyses to validate the transcriptomics results demonstrated that the symbiont increases host density hence providing a fitness advantage. Comparative transcriptomics shows gene expression modulation of a ciliate caused by its bacterial endosymbiont thus revealing new adaptive advantages of the symbiosis. Caedibacter taeniospiralis apparently increases its host fitness via manipulation of metabolic pathways and cell cycle control.
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Affiliation(s)
- Katrin Grosser
- Microbiology, Institute of Biology II, Albert-Ludwigs University of Freiburg, Germany
| | - Pathmanaban Ramasamy
- Excellence Cluster for Multimodal Computing and Interaction, Saarland Informatics Campus, Saarland University, Saarbruecken, Germany.,Molecular Cell Dynamics, Centre for Human and Molecular Biology, Saarland University, Saarbruecken, Germany
| | - Azim Dehghani Amirabad
- Excellence Cluster for Multimodal Computing and Interaction, Saarland Informatics Campus, Saarland University, Saarbruecken, Germany.,Computational Biology and Applied Algorithmics, Max-Planck-Institute for Informatics, Saarland Informatics Campus, Saarbruecken, Germany
| | - Marcel H Schulz
- Excellence Cluster for Multimodal Computing and Interaction, Saarland Informatics Campus, Saarland University, Saarbruecken, Germany.,Computational Biology and Applied Algorithmics, Max-Planck-Institute for Informatics, Saarland Informatics Campus, Saarbruecken, Germany
| | - Gilles Gasparoni
- Genetics, Centre for Human and Molecular Biology, Saarland University, Saarbruecken, Germany
| | - Martin Simon
- Molecular Cell Dynamics, Centre for Human and Molecular Biology, Saarland University, Saarbruecken, Germany
| | - Martina Schrallhammer
- Microbiology, Institute of Biology II, Albert-Ludwigs University of Freiburg, Germany
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116
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Targeting the gut microbiota to influence brain development and function in early life. Neurosci Biobehav Rev 2018; 95:191-201. [PMID: 30195933 DOI: 10.1016/j.neubiorev.2018.09.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 09/03/2018] [Accepted: 09/04/2018] [Indexed: 12/16/2022]
Abstract
In the first 2-3 years of life, the gut microbiota of infants quickly becomes diverse and rich. Disruptions in the evolving gut microbiota during this critical developmental period can impact brain development. Communication between the microbiota, gut and brain is driven by hormonal and neural regulation, as well as immune and metabolic pathways, however, our understanding of how the parallel developments that may underlie this communication are limited. In this paper, we review the known associations between the gut microbiota and brain development and brain function in early life, speculate on the potential mechanisms involved in this complex relationship and describe how nutritional intervention can further modulate the microbiota and, ultimately, brain development and function.
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117
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Cui YF, Wang FJ, Yu L, Ye HH, Yang GB. Metagenomic comparison of the rectal microbiota between rhesus macaques ( Macaca mulatta) and cynomolgus macaques ( Macaca fascicularis). Zool Res 2018; 40:89-93. [PMID: 30127329 PMCID: PMC6378564 DOI: 10.24272/j.issn.2095-8137.2018.061] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Rhesus macaques (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis) are frequently used in establishing animal models for human diseases. To determine the differences in gut microbiota between these species, rectal swabs from 20 rhesus macaques and 21 cynomolgus macaques were collected, and the microbial composition was examined by deep sequencing of the 16S rRNA gene. We found that the rectal microbiota of cynomolgus macaques exhibited significantly higher alpha diversity than that of rhesus macaques, although the observed number of operational taxonomic units (OTUs) was almost the same. The dominant taxa at both the phylum and genus levels were similar between the two species, although the relative abundances of these dominant taxa were significantly different between them. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) showed significant differences in the functional components between the microbiota of the two species, in particular the lipopolysaccharide (LPS) synthesis proteins. The above data indicated significant differences in microbial composition and function between these two closely related macaque species, which should be taken into consideration in the future selection of these animals for disease models.
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Affiliation(s)
- Yan-Fang Cui
- National Center for AIDS/STD Control and Prevention, China-CDC, Beijing 102206, China
| | - Feng-Jie Wang
- National Center for AIDS/STD Control and Prevention, China-CDC, Beijing 102206, China
| | - Lei Yu
- National Center for AIDS/STD Control and Prevention, China-CDC, Beijing 102206, China
| | - Hua-Hu Ye
- Laboratory Animal Center of the Academy of Military Medical Sciences, Beijing 100071, China
| | - Gui-Bo Yang
- National Center for AIDS/STD Control and Prevention, China-CDC, Beijing 102206, China; E-mail:
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118
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Enciu AM, Codrici E, Mihai S, Manole E, Pop S, Codorean E, Niculite CM, Necula L, Tarcomnicu I, Gille E, Tanase CP. Role of Nutraceuticals in Modulation of Gut-Brain Axis in Elderly Persons. Gerontology 2018. [DOI: 10.5772/intechopen.73005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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119
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Sarkar A, Harty S, Lehto SM, Moeller AH, Dinan TG, Dunbar RIM, Cryan JF, Burnet PWJ. The Microbiome in Psychology and Cognitive Neuroscience. Trends Cogn Sci 2018; 22:611-636. [PMID: 29907531 DOI: 10.1016/j.tics.2018.04.006] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 04/23/2018] [Accepted: 04/25/2018] [Indexed: 02/07/2023]
Abstract
Psychology and microbiology make unlikely friends, but the past decade has witnessed striking bidirectional associations between intrinsic gut microbes and the brain, relationships with largely untested psychological implications. Although microbe-brain relationships are receiving a great deal of attention in biomedicine and neuroscience, psychologists have yet to join this journey. Here, we illustrate microbial associations with emotion, cognition, and social behavior. However, despite considerable enthusiasm and potential, technical and conceptual limitations including low statistical power and lack of mechanistic descriptions prevent a nuanced understanding of microbiome-brain-behavior relationships. Our goal is to describe microbial effects in domains of cognitive significance and the associated challenges to stimulate interdisciplinary research on the contribution of this hidden kingdom to psychological processes.
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Affiliation(s)
- Amar Sarkar
- Department of Experimental Psychology, University of Oxford, Oxford, UK; Department of Physiology, Development, and Neuroscience, University of Cambridge, Cambridge, UK; Trinity College, University of Cambridge, Cambridge, UK.
| | - Siobhán Harty
- Department of Experimental Psychology, University of Oxford, Oxford, UK; Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Dublin 2, Ireland
| | - Soili M Lehto
- Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Finland; Institute of Clinical Medicine / Psychiatry, University of Eastern Finland, Kuopio, Finland; Department of Psychiatry, Kuopio University Hospital, Kuopio, Finland
| | - Andrew H Moeller
- Miller Institute for Basic Research in Science, University of California, Berkeley, CA, USA
| | - Timothy G Dinan
- APC Microbiome Institute, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Sciences, University College Cork, Cork, Ireland
| | - Robin I M Dunbar
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - John F Cryan
- Department of Psychiatry and Neurobehavioural Sciences, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience University College Cork, Cork, Ireland
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120
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Stilling RM, Moloney GM, Ryan FJ, Hoban AE, Bastiaanssen TF, Shanahan F, Clarke G, Claesson MJ, Dinan TG, Cryan JF. Social interaction-induced activation of RNA splicing in the amygdala of microbiome-deficient mice. eLife 2018; 7:33070. [PMID: 29809134 PMCID: PMC5995540 DOI: 10.7554/elife.33070] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 05/15/2018] [Indexed: 12/11/2022] Open
Abstract
Social behaviour is regulated by activity of host-associated microbiota across multiple species. However, the molecular mechanisms mediating this relationship remain elusive. We therefore determined the dynamic, stimulus-dependent transcriptional regulation of germ-free (GF) and GF mice colonised post weaning (exGF) in the amygdala, a brain region critically involved in regulating social interaction. In GF mice the dynamic response seen in controls was attenuated and replaced by a marked increase in expression of splicing factors and alternative exon usage in GF mice upon stimulation, which was even more pronounced in exGF mice. In conclusion, we demonstrate a molecular basis for how the host microbiome is crucial for a normal behavioural response during social interaction. Our data further suggest that social behaviour is correlated with the gene-expression response in the amygdala, established during neurodevelopment as a result of host-microbe interactions. Our findings may help toward understanding neurodevelopmental events leading to social behaviour dysregulation, such as those found in autism spectrum disorders (ASDs). In our bodies, there are at least as many microbial cells as human cells. These microbes, known collectively as the microbiome, influence the activity of our brain and also our behaviour. Studies in species from insects to primates have shown that the microbiome affects social behaviour in particular. For example, germ-free mice, which grow up in a sterile environment and thus have no bacteria in or on their bodies, are less sociable than normal mice. For animals to show behaviours such as social interaction, cells in specific regions of the brain must change the activity of their genes. These brain regions include the amygdala, which is part of the brain’s emotion processing network, and also contributes to fear and anxiety responses. Stilling et al. set out to determine whether gene activity in the amygdala during social interaction differs between germ-free mice and those with a normal microbiome. Stilling et al. placed each mouse into a box with three chambers. One chamber contained an unfamiliar mouse while another contained an inanimate object. Germ-free mice were less sociable and spent less time than control animals interacting with the unfamiliar mouse. Before entering either test chamber, the germ-free animals showed signs of excessive activity in the amygdala. During social interaction, they displayed a strikingly different pattern of gene activity in this brain region compared to controls. In particular, they had increased levels of a process called alternative splicing. This process enables cells to produce many different proteins from a single gene. These results reveal one of the steps leading from absence of bacteria during brain development to reduced sociability in adulthood in mice. Increases in gene activity in the amygdala may provide clues to the processes underlying reduced sociability in people with autism spectrum disorders. This new study thus deepens our understanding of the link between the microbiome and brain health.
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Affiliation(s)
- Roman M Stilling
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Gerard M Moloney
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Feargal J Ryan
- APC Microbiome Institute, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | - Alan E Hoban
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Thomaz Fs Bastiaanssen
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Fergus Shanahan
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - Marcus J Claesson
- APC Microbiome Institute, University College Cork, Cork, Ireland.,School of Microbiology, University College Cork, Cork, Ireland
| | - Timothy G Dinan
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - John F Cryan
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
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121
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Hsueh PT, Lin HH, Wang HH, Liu CL, Ni WF, Liu JK, Chang HH, Sun DS, Chen YS, Chen YL. Immune imbalance of global gene expression, and cytokine, chemokine and selectin levels in the brains of offspring with social deficits via maternal immune activation. GENES BRAIN AND BEHAVIOR 2018; 17:e12479. [PMID: 29656594 DOI: 10.1111/gbb.12479] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 02/27/2018] [Accepted: 04/05/2018] [Indexed: 12/13/2022]
Abstract
The murine maternal immune activation (MIA) offspring model enables longitudinal studies to explore aberrant social behaviors similar to those observed in humans. High levels of cytokines, chemokines and cell adhesion molecules (CAM) have been found in the plasma and/or brains of psychiatric patients. We hypothesized that upregulation of the systemic or brain immune response has an augmenting effect by potentially increasing the interplay between the neuronal and immune systems during the growth of the MIA offspring. In this study, a C57BL/6j MIA female offspring model exhibiting social deficits was established. The expression of fetal interferon (IFN)-stimulated (gbp3, irgm1, ifi44), adolescent immunodevelopmental transcription factor (eg, r2, tfap2b), hormone (pomc, hcrt), adult selectin (sell, selp) and neuroligin (nlgn2) genes was altered. Systemic upregulation of endogenous IL-10 occurred at the adult stage, while both IL-1β and IL-6 were increased and persisted in the sera throughout the growth of the MIA offspring. The cerebral IL-6 levels were endogenously upregulated, but both MCP-1 (macrophage inflammatory protein-1) and L-selectin levels were downregulated at the adolescent and/or adult stages. However, the MIA offspring were susceptible to lipopolysaccharide (LPS) stimulation. After reinjecting the MIA offspring with LPS in adulthood, a variety of sera and cerebral cytokines, chemokines and CAMs were increased. Particularly, both MCP-1 and L-selectin showed relatively high expression in the brain compared with the expression levels in phosphate-buffered saline (PBS)-treated offspring injected with LPS. Potentially, MCP-1 was attracted to the L-selectin-mediated immune cells due to augmentation of the immune response following stimulation in MIA female offspring.
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Affiliation(s)
- P-T Hsueh
- Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - H-H Lin
- Department of Internal Medicine, National Yang-Ming University, Taipei, Taiwan.,Section of Infectious Disease, Department of Medicine, E-Da Hospital, Kaohsiung, Taiwan
| | - H-H Wang
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - C-L Liu
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - W-F Ni
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - J-K Liu
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - H-H Chang
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
| | - D-S Sun
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
| | - Y-S Chen
- Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Y-L Chen
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
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122
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The microbiome regulates amygdala-dependent fear recall. Mol Psychiatry 2018; 23:1134-1144. [PMID: 28507320 PMCID: PMC5984090 DOI: 10.1038/mp.2017.100] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 02/20/2017] [Accepted: 03/16/2017] [Indexed: 12/25/2022]
Abstract
The amygdala is a key brain region that is critically involved in the processing and expression of anxiety and fear-related signals. In parallel, a growing number of preclinical and human studies have implicated the microbiome-gut-brain in regulating anxiety and stress-related responses. However, the role of the microbiome in fear-related behaviours is unclear. To this end we investigated the importance of the host microbiome on amygdala-dependent behavioural readouts using the cued fear conditioning paradigm. We also assessed changes in neuronal transcription and post-transcriptional regulation in the amygdala of naive and stimulated germ-free (GF) mice, using a genome-wide transcriptome profiling approach. Our results reveal that GF mice display reduced freezing during the cued memory retention test. Moreover, we demonstrate that under baseline conditions, GF mice display altered transcriptional profile with a marked increase in immediate-early genes (for example, Fos, Egr2, Fosb, Arc) as well as genes implicated in neural activity, synaptic transmission and nervous system development. We also found a predicted interaction between mRNA and specific microRNAs that are differentially regulated in GF mice. Interestingly, colonized GF mice (ex-GF) were behaviourally comparable to conventionally raised (CON) mice. Together, our data demonstrates a unique transcriptional response in GF animals, likely because of already elevated levels of immediate-early gene expression and the potentially underlying neuronal hyperactivity that in turn primes the amygdala for a different transcriptional response. Thus, we demonstrate for what is to our knowledge the first time that the presence of the host microbiome is crucial for the appropriate behavioural response during amygdala-dependent memory retention.
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123
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Stiemsma LT, Michels KB. The Role of the Microbiome in the Developmental Origins of Health and Disease. Pediatrics 2018; 141:e20172437. [PMID: 29519955 PMCID: PMC5869344 DOI: 10.1542/peds.2017-2437] [Citation(s) in RCA: 209] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/29/2017] [Indexed: 12/15/2022] Open
Abstract
Although the prominent role of the microbiome in human health has been established, the early-life microbiome is now being recognized as a major influence on long-term human health and development. Variations in the composition and functional potential of the early-life microbiome are the result of lifestyle factors, such as mode of birth, breastfeeding, diet, and antibiotic usage. In addition, variations in the composition of the early-life microbiome have been associated with specific disease outcomes, such as asthma, obesity, and neurodevelopmental disorders. This points toward this bacterial consortium as a mediator between early lifestyle factors and health and disease. In addition, variations in the microbial intrauterine environment may predispose neonates to specific health outcomes later in life. A role of the microbiome in the Developmental Origins of Health and Disease is supported in this collective research. Highlighting the early-life critical window of susceptibility associated with microbiome development, we discuss infant microbial colonization, beginning with the maternal-to-fetal exchange of microbes in utero and up through the influence of breastfeeding in the first year of life. In addition, we review the available disease-specific evidence pointing toward the microbiome as a mechanistic mediator in the Developmental Origins of Health and Disease.
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Affiliation(s)
- Leah T Stiemsma
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California
| | - Karin B Michels
- Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, California
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124
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Cristiano C, Lama A, Lembo F, Mollica MP, Calignano A, Mattace Raso G. Interplay Between Peripheral and Central Inflammation in Autism Spectrum Disorders: Possible Nutritional and Therapeutic Strategies. Front Physiol 2018; 9:184. [PMID: 29563885 PMCID: PMC5845898 DOI: 10.3389/fphys.2018.00184] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 02/20/2018] [Indexed: 12/16/2022] Open
Abstract
Pre- and post-natal factors can affect brain development and function, impacting health outcomes with particular relevance to neurodevelopmental diseases, such as autism spectrum disorders (ASDs). Maternal obesity and its associated complications have been related to the increased risk of ASDs in offspring. Indeed, animals exposed to maternal obesity or high fat diets are prone to social communication impairment and repetitive behavior, the hallmarks of autism. During development, fatty acids and sugars, as well as satiety hormones, like insulin and leptin, and inflammatory factors related to obesity-induced low grade inflammation, could play a role in the impairment of neuroendocrine system and brain neuronal circuits regulating behavior in offspring. On the other side, post-natal factors, such as mode of delivery, stress, diet, or antibiotic treatment are associated to a modification of gut microbiota composition, perturbing microbiota-gut-brain axis. Indeed, the interplay between the gastrointestinal tract and the central nervous system not only occurs through neural, hormonal, and immune pathways, but also through microbe-derived metabolic products. The modification of unhealthy perinatal and postnatal environment, manipulation of gut microbiota, nutritional, and dietary interventions could represent possible strategies in preventing or limiting ASDs, through targeting inflammatory process and gut microbiota.
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Affiliation(s)
- Claudia Cristiano
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Adriano Lama
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Francesca Lembo
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Maria P Mollica
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Antonio Calignano
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
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125
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Doenyas C. Gut Microbiota, Inflammation, and Probiotics on Neural Development in Autism Spectrum Disorder. Neuroscience 2018; 374:271-286. [DOI: 10.1016/j.neuroscience.2018.01.060] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 01/26/2018] [Accepted: 01/30/2018] [Indexed: 01/01/2023]
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126
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Miquel S, Champ C, Day J, Aarts E, Bahr BA, Bakker M, Bánáti D, Calabrese V, Cederholm T, Cryan J, Dye L, Farrimond JA, Korosi A, Layé S, Maudsley S, Milenkovic D, Mohajeri MH, Sijben J, Solomon A, Spencer JPE, Thuret S, Vanden Berghe W, Vauzour D, Vellas B, Wesnes K, Willatts P, Wittenberg R, Geurts L. Poor cognitive ageing: Vulnerabilities, mechanisms and the impact of nutritional interventions. Ageing Res Rev 2018; 42:40-55. [PMID: 29248758 DOI: 10.1016/j.arr.2017.12.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/08/2017] [Accepted: 12/08/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Ageing is a highly complex process marked by a temporal cascade of events, which promote alterations in the normal functioning of an individual organism. The triggers of normal brain ageing are not well understood, even less so the factors which initiate and steer the neuronal degeneration, which underpin disorders such as dementia. A wealth of data on how nutrients and diets may support cognitive function and preserve brain health are available, yet the molecular mechanisms underlying their biological action in both normal ageing, age-related cognitive decline, and in the development of neurodegenerative disorders have not been clearly elucidated. OBJECTIVES This review aims to summarise the current state of knowledge of vulnerabilities that predispose towards dysfunctional brain ageing, highlight potential protective mechanisms, and discuss dietary interventions that may be used as therapies. A special focus of this paper is on the impact of nutrition on neuroprotection and the underlying molecular mechanisms, and this focus reflects the discussions held during the 2nd workshop 'Nutrition for the Ageing Brain: Functional Aspects and Mechanisms' in Copenhagen in June 2016. The present review is the most recent in a series produced by the Nutrition and Mental Performance Task Force under the auspice of the International Life Sciences Institute Europe (ILSI Europe). CONCLUSION Coupling studies of cognitive ageing with studies investigating the effect of nutrition and dietary interventions as strategies targeting specific mechanisms, such as neurogenesis, protein clearance, inflammation, and non-coding and microRNAs is of high value. Future research on the impact of nutrition on cognitive ageing will need to adopt a longitudinal approach and multimodal nutritional interventions will likely need to be imposed in early-life to observe significant impact in older age.
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Affiliation(s)
- Sophie Miquel
- Mars-Wrigley, 1132 W. Blackhawk Street, Chicago, IL 60642, United States
| | - Claire Champ
- Human Appetite Research Unit, School of Psychology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Jon Day
- Cerebrus Associates Limited, The White House, 2 Meadrow, Godalming, Surrey, GU7 3HN, United Kingdom
| | - Esther Aarts
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen, Kapittelweg 29, 6525 EN Nijmegen, The Netherlands
| | - Ben A Bahr
- Biotechnology Research and Training Centre, University of North Carolina - Pembroke, United States
| | - Martijntje Bakker
- The Netherlands Organisation for Health Research and Development, Laan van Nieuw Oost-Indië 334, 2593 CE The Hague, The Netherlands
| | - Diána Bánáti
- International Life Sciences Institute, Europe (ILSI Europe), Av E. Mounier 83, Box 6, 1200 Brussels, Belgium
| | - Vittorio Calabrese
- University of Catania, Department of Biomedical and Biotechnological Sciences, Biological Tower - Via Santa Sofia, 97, Catania, Italy
| | - Tommy Cederholm
- University of Uppsala, Institutionen för folkhälso- och vårdvetenskap, Klinisk nutrition och metabolism, Uppsala Science Park, 751 85 Uppsala, Sweden
| | - John Cryan
- Anatomy & Neuroscience, University College Cork, 386 Western Gateway Building, Cork, Ireland
| | - Louise Dye
- Human Appetite Research Unit, School of Psychology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | | | - Aniko Korosi
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Sophie Layé
- Nutrition et Neurobiologie Intégrée, INRA Bordeaux University, 146 rue Léo Saignat, 33076 Bordeaux cedex, France
| | - Stuart Maudsley
- Department of Biomedical Research and VIB-UAntwerp Center for Molecular Neurology, University of Antwerp, Gebouw V, Campus Drie Eiken, Universiteitsplein 1, 2610 Antwerpen, Belgium
| | - Dragan Milenkovic
- INRA, Human Nutrition Unit, UCA, F-63003, Clermont-Ferrand, France; Department of Internal Medicine, Division of Cardiovascular Medicine, School of Medicine, University of California Davis, Davis, CA 95616, United States
| | - M Hasan Mohajeri
- DSM Nutritional Products Ltd., Wurmisweg 576, Kaiseraugst 4303, Switzerland
| | - John Sijben
- Nutricia Research, Nutricia Advanced Medical Nutrition, PO Box 80141, 3508TC, Utrecht, The Netherlands
| | - Alina Solomon
- Aging Research Center, Karolinska Institutet, Gävlegatan 16, SE-113 30 Stockholm, Sweden
| | - Jeremy P E Spencer
- Hugh Sinclair Unit of Human Nutrition and Institute for Cardiovascular and Metabolic Research, Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading, RG6 6AP, United Kingdom
| | - Sandrine Thuret
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, The Maurice Wohl Clinical Neuroscience Institute,125 Coldharbour Lane, SE5 9NU London, United Kingdom
| | - Wim Vanden Berghe
- PPES, Department Biomedical Sciences, University Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Antwerp, Belgium
| | - David Vauzour
- University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Bruno Vellas
- Department of Geriatric Medicine, CHU Toulouse, Gerontopole, Toulouse, France
| | - Keith Wesnes
- Wesnes Cognition Limited, Little Paddock, Streatley on Thames, RG8 9RD, United Kingdom; Medical School, University of Exeter, Exeter, United Kingdom; Department of Psychology, Northumbria University, Newcastle, United Kingdom; Centre for Human Psychopharmacology, Swinburne University, Melbourne, Australia; Medicinal Plant Research Group, Newcastle University, United Kingdom
| | - Peter Willatts
- School of Psychology, University of Dundee Nethergate, Dundee, DD1 4HN, United Kingdom
| | - Raphael Wittenberg
- London School of Economics and Political Science, Personal Social Services Research Unit, London, United Kingdom
| | - Lucie Geurts
- International Life Sciences Institute, Europe (ILSI Europe), Av E. Mounier 83, Box 6, 1200 Brussels, Belgium.
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127
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Needham BD, Tang W, Wu WL. Searching for the gut microbial contributing factors to social behavior in rodent models of autism spectrum disorder. Dev Neurobiol 2018; 78:474-499. [PMID: 29411548 DOI: 10.1002/dneu.22581] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/07/2017] [Accepted: 01/08/2018] [Indexed: 12/15/2022]
Abstract
Social impairment is one of the major symptoms in multiple psychiatric disorders, including autism spectrum disorder (ASD). Accumulated studies indicate a crucial role for the gut microbiota in social development, but these mechanisms remain unclear. This review focuses on two strategies adopted to elucidate the complicated relationship between gut bacteria and host social behavior. In a top-down approach, researchers have attempted to correlate behavioral abnormalities with altered gut microbial profiles in rodent models of ASD, including BTBR mice, maternal immune activation (MIA), maternal valproic acid (VPA) and maternal high-fat diet (MHFD) offspring. In a bottom-up approach, researchers use germ-free (GF) animals, antibiotics, probiotics or pathogens to manipulate the intestinal environment and ascertain effects on social behavior. The combination of both approaches will hopefully pinpoint specific bacterial communities that control host social behavior. Further discussion of how brain development and circuitry is impacted by depletion of gut microbiota is also included. The converging evidence strongly suggests that gut microbes affect host social behavior through the alteration of brain neural circuits. Investigation of intestinal microbiota and host social behavior will unveil any bidirectional communication between the gut and brain and provide alternative therapeutic targets for ASD. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 78: 474-499, 2018.
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Affiliation(s)
- Brittany D Needham
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, California
| | - Weiyi Tang
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, California
| | - Wei-Li Wu
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, California
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128
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Temko JE, Bouhlal S, Farokhnia M, Lee MR, Cryan JF, Leggio L. The Microbiota, the Gut and the Brain in Eating and Alcohol Use Disorders: A 'Ménage à Trois'? Alcohol Alcohol 2018; 52:403-413. [PMID: 28482009 DOI: 10.1093/alcalc/agx024] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/05/2017] [Indexed: 02/06/2023] Open
Abstract
Aims Accumulating evidence for the influence of the gut microbiota on the bidirectional communication along the gut-brain axis suggests a role of the gut microbiota in eating disorders (EDs) and alcohol and substance use disorders. The potential influence of altered gut microbiota (dysbiosis) on behaviors associated with such disorders may have implications for developing therapeutic interventions. Methods A systematic review of preclinical and clinical studies evaluating the gut microbiota, EDs and alcohol and substance use disorders was conducted using MEDLINE, Embase and Web of Science databases with the objective being to examine the role of the gut microbiota in behavioral correlates of these disorders. Original papers focused on the gut microbiota and potential behavioral implications were deemed eligible for consideration. Results The resulting 12 publications were limited to gut microbiota studies related to EDs and alcohol and substance use disorders. Some studies suggest that dysbiosis and gut microbial byproducts may influence the pathophysiology of EDs via direct and indirect interference with peptide hormone signaling. Additionally, dysbiosis was shown to be correlated with alcohol use disorder-related symptoms, i.e. craving, depression and anxiety. Finally, a mouse study suggests that manipulations in the gut microbiota may affect cocaine-related behaviors. Conclusions Promising, albeit preliminary, findings suggest a potential role of the gut microbiota in behavioral correlates of EDs and alcohol and substance use disorders. Short summary Preliminary evidence exists supporting the role of the gut microbiota in eating disorders and alcohol and substance use disorders, although additional investigation is needed to determine what is causative versus epiphenomenological.
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Affiliation(s)
- Jamie E Temko
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, 10 Center Drive (10CRC/15330), Bethesda, MD 20892-1108, USA
| | - Sofia Bouhlal
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, 10 Center Drive (10CRC/15330), Bethesda, MD 20892-1108, USA
| | - Mehdi Farokhnia
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, 10 Center Drive (10CRC/15330), Bethesda, MD 20892-1108, USA
| | - Mary R Lee
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, 10 Center Drive (10CRC/15330), Bethesda, MD 20892-1108, USA
| | - John F Cryan
- APC Microbiome Institute and Department of Anatomy and Neuroscience, University College Cork, Western Gateway Building, Cork, Ireland
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, 10 Center Drive (10CRC/15330), Bethesda, MD 20892-1108, USA.,Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, 121 South Main Street, Providence, RI 02903, USA
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129
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Wiley NC, Dinan TG, Ross RP, Stanton C, Clarke G, Cryan JF. The microbiota-gut-brain axis as a key regulator of neural function and the stress response: Implications for human and animal health. J Anim Sci 2018; 95:3225-3246. [PMID: 28727115 DOI: 10.2527/jas.2016.1256] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The brain-gut-microbiota axis comprises an extensive communication network between the brain, the gut, and the microbiota residing there. Development of a diverse gut microbiota is vital for multiple features of behavior and physiology, as well as many fundamental aspects of brain structure and function. Appropriate early-life assembly of the gut microbiota is also believed to play a role in subsequent emotional and cognitive development. If the composition, diversity, or assembly of the gut microbiota is impaired, this impairment can have a negative impact on host health and lead to disorders such as obesity, diabetes, inflammatory diseases, and even potentially neuropsychiatric illnesses, including anxiety and depression. Therefore, much research effort in recent years has focused on understanding the potential of targeting the intestinal microbiota to prevent and treat such disorders. This review aims to explore the influence of the gut microbiota on host neural function and behavior, particularly those of relevance to stress-related disorders. The involvement of microbiota in diverse neural functions such as myelination, microglia function, neuronal morphology, and blood-brain barrier integrity across the life span, from early life to adolescence to old age, will also be discussed. Nurturing an optimal gut microbiome may also prove beneficial in animal science as a means to manage stressful situations and to increase productivity of farm animals. The implications of these observations are manifold, and researchers are hopeful that this promising body of preclinical work can be successfully translated to the clinic and beyond.
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130
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Abstract
The microbial ecosystem that inhabits the gastrointestinal tract of all mammals-the gut microbiota-has been in a symbiotic relationship with its hosts over many millennia. Thanks to modern technology, the myriad of functions that are controlled or modulated by the gut microbiota are beginning to unfold. One of the systems that is emerging to closely interact with the gut microbiota is the body's major neuroendocrine system that controls various body processes in response to stress, the hypothalamic-pituitary-adrenal (HPA) axis. This interaction is of pivotal importance; as various disorders of the microbiota-gut-brain axis are associated with dysregulation of the HPA axis. The present contribution describes the bidirectional communication between the gut microbiota and the HPA axis and delineates the potential underlying mechanisms. In this regard, it is important to note that the communication between the gut microbiota and the HPA axis is closely interrelated with other systems, such as the immune system, the intestinal barrier and blood-brain barrier, microbial metabolites, and gut hormones, as well as the sensory and autonomic nervous systems. These communication pathways will be exemplified through preclinical models of early life stress, beneficial roles of probiotics and prebiotics, evidence from germ-free mice, and antibiotic-induced modulation of the gut microbiota.
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Affiliation(s)
- Aitak Farzi
- Otto Loewi Research Center, Pharmacology Section, Medical University of Graz, Graz, Austria.
| | - Esther E Fröhlich
- Otto Loewi Research Center, Pharmacology Section, Medical University of Graz, Graz, Austria
| | - Peter Holzer
- Otto Loewi Research Center, Pharmacology Section, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
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131
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Horne R, Foster JA. Metabolic and Microbiota Measures as Peripheral Biomarkers in Major Depressive Disorder. Front Psychiatry 2018; 9:513. [PMID: 30405455 PMCID: PMC6204462 DOI: 10.3389/fpsyt.2018.00513] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 09/28/2018] [Indexed: 12/21/2022] Open
Abstract
Advances in understanding the role of the microbiome in physical and mental health are at the forefront of medical research and hold potential to have a direct impact on precision medicine approaches. In the past 7 years, we have studied the role of microbiota-brain communication on behavior in mouse models using germ-free mice, mice exposed to antibiotics, and healthy specific pathogen free mice. Through our work and that of others, we have seen an amazing increase in our knowledge of how bacteria signal to the brain and the implications this has for psychiatry. Gut microbiota composition and function are influenced both by genetics, age, sex, diet, life experiences, and many other factors of psychiatric and bodily disorders and thus may act as potential biomarkers of the gut-brain axis that could be used in psychiatry and co-morbid conditions. There is a particular need in major depressive disorder and other mental illness to identify biomarkers that can stratify patients into more homogeneous groups to provide better treatment and for development of new therapeutic approaches. Peripheral outcome measures of host-microbe bidirectional communication have significant translational value as biomarkers. Enabling stratification of clinical populations, based on individual biological differences, to predict treatment response to pharmacological and non-pharmacological interventions. Here we consider the links between co-morbid metabolic syndrome and depression, focusing on biomarkers including leptin and ghrelin in combination with assessing gut microbiota composition, as a potential tool to help identify individual differences in depressed population.
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Affiliation(s)
- Rachael Horne
- Department of Psychiatry & Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
| | - Jane A Foster
- Department of Psychiatry & Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada.,Department of Psychiatry, St. Michael's Hospital, Toronto, ON, Canada
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132
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Ntranos A, Casaccia P. The Microbiome-Gut-Behavior Axis: Crosstalk Between the Gut Microbiome and Oligodendrocytes Modulates Behavioral Responses. Neurotherapeutics 2018; 15:31-35. [PMID: 29282673 PMCID: PMC5794707 DOI: 10.1007/s13311-017-0597-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Environmental and dietary stimuli have always been implicated in brain development and behavioral responses. The gut, being the major portal of communication with the external environment, has recently been brought to the forefront of this interaction with the establishment of a gut-brain axis in health and disease. Moreover, recent breakthroughs in germ-free and antibiotic-treated mice have demonstrated the significant impact of the microbiome in modulating behavioral responses in mice and have established a more specific microbiome-gut-behavior axis. One of the mechanisms by which this axis affects social behavior is by regulating myelination at the prefrontal cortex, an important site for complex cognitive behavior planning and decision-making. The prefrontal cortex exhibits late myelination of its axonal projections that could extend into the third decade of life in humans, which make it susceptible to external influences, such as microbial metabolites. Changes in the gut microbiome were shown to alter the composition of the microbial metabolome affecting highly permeable bioactive compounds, such as p-cresol, which could impair oligodendrocyte differentiation. Dysregulated myelination in the prefrontal cortex is then able to affect behavioral responses in mice, shifting them towards social isolation. The reduced social interactions could then limit microbial exchange, which could otherwise pose a threat to the survival of the existing microbial community in the host and, thus, provide an evolutionary advantage to the specific microbial community. In this review, we will analyze the microbiome-gut-behavior axis, describe the interactions between the gut microbiome and oligodendrocytes and highlight their role in the modulation of social behavior.
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Affiliation(s)
- Achilles Ntranos
- The Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Patrizia Casaccia
- The Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Neuroscience Initiative, CUNY Advanced Science Research Center, New York, NY, 10031, USA.
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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133
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Spichak S, Guzzetta KE, O’Leary OF, Clarke G, Dinan TG, Cryan JF. Without a bug’s life: Germ-free rodents to interrogate microbiota-gut-neuroimmune interactions. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.ddmod.2019.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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134
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Holzer P, Farzi A, Hassan AM, Zenz G, Jačan A, Reichmann F. Visceral Inflammation and Immune Activation Stress the Brain. Front Immunol 2017; 8:1613. [PMID: 29213271 PMCID: PMC5702648 DOI: 10.3389/fimmu.2017.01613] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 11/07/2017] [Indexed: 12/20/2022] Open
Abstract
Stress refers to a dynamic process in which the homeostasis of an organism is challenged, the outcome depending on the type, severity, and duration of stressors involved, the stress responses triggered, and the stress resilience of the organism. Importantly, the relationship between stress and the immune system is bidirectional, as not only stressors have an impact on immune function, but alterations in immune function themselves can elicit stress responses. Such bidirectional interactions have been prominently identified to occur in the gastrointestinal tract in which there is a close cross-talk between the gut microbiota and the local immune system, governed by the permeability of the intestinal mucosa. External stressors disturb the homeostasis between microbiota and gut, these disturbances being signaled to the brain via multiple communication pathways constituting the gut-brain axis, ultimately eliciting stress responses and perturbations of brain function. In view of these relationships, the present article sets out to highlight some of the interactions between peripheral immune activation, especially in the visceral system, and brain function, behavior, and stress coping. These issues are exemplified by the way through which the intestinal microbiota as well as microbe-associated molecular patterns including lipopolysaccharide communicate with the immune system and brain, and the mechanisms whereby overt inflammation in the GI tract impacts on emotional-affective behavior, pain sensitivity, and stress coping. The interactions between the peripheral immune system and the brain take place along the gut-brain axis, the major communication pathways of which comprise microbial metabolites, gut hormones, immune mediators, and sensory neurons. Through these signaling systems, several transmitter and neuropeptide systems within the brain are altered under conditions of peripheral immune stress, enabling adaptive processes related to stress coping and resilience to take place. These aspects of the impact of immune stress on molecular and behavioral processes in the brain have a bearing on several disturbances of mental health and highlight novel opportunities of therapeutic intervention.
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Affiliation(s)
- Peter Holzer
- Research Unit of Translational Neurogastroenterology, Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria.,BioTechMed-Graz, Graz, Austria
| | - Aitak Farzi
- Research Unit of Translational Neurogastroenterology, Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Ahmed M Hassan
- Research Unit of Translational Neurogastroenterology, Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Geraldine Zenz
- Research Unit of Translational Neurogastroenterology, Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
| | - Angela Jačan
- CBmed GmbH-Center for Biomarker Research in Medicine, Graz, Austria
| | - Florian Reichmann
- Research Unit of Translational Neurogastroenterology, Institute of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria
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135
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Cowan CSM, Hoban AE, Ventura-Silva AP, Dinan TG, Clarke G, Cryan JF. Gutsy Moves: The Amygdala as a Critical Node in Microbiota to Brain Signaling. Bioessays 2017; 40. [DOI: 10.1002/bies.201700172] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/23/2017] [Indexed: 12/12/2022]
Affiliation(s)
| | - Alan E. Hoban
- Department of Anatomy and Neuroscience, University College Cork; Cork Ireland
| | | | - Timothy G. Dinan
- APC Microbiome Institute, University College Cork; Cork Ireland
- Department of Psychiatry and Neurobehavioural Science, University College Cork; Cork Ireland
| | - Gerard Clarke
- APC Microbiome Institute, University College Cork; Cork Ireland
- Department of Psychiatry and Neurobehavioural Science, University College Cork; Cork Ireland
| | - John F. Cryan
- APC Microbiome Institute, University College Cork; Cork Ireland
- Department of Anatomy and Neuroscience, University College Cork; Cork Ireland
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136
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Burokas A, Arboleya S, Moloney RD, Peterson VL, Murphy K, Clarke G, Stanton C, Dinan TG, Cryan JF. Targeting the Microbiota-Gut-Brain Axis: Prebiotics Have Anxiolytic and Antidepressant-like Effects and Reverse the Impact of Chronic Stress in Mice. Biol Psychiatry 2017; 82:472-487. [PMID: 28242013 DOI: 10.1016/j.biopsych.2016.12.031] [Citation(s) in RCA: 552] [Impact Index Per Article: 78.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 12/28/2016] [Accepted: 12/29/2016] [Indexed: 02/08/2023]
Abstract
BACKGROUND The realization that the microbiota-gut-brain axis plays a critical role in health and disease, including neuropsychiatric disorders, is rapidly advancing. Nurturing a beneficial gut microbiome with prebiotics, such as fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS), is an appealing but underinvestigated microbiota manipulation. Here we tested whether chronic prebiotic treatment modifies behavior across domains relevant to anxiety, depression, cognition, stress response, and social behavior. METHODS C57BL/6J male mice were administered FOS, GOS, or a combination of FOS+GOS for 3 weeks prior to testing. Plasma corticosterone, microbiota composition, and cecal short-chain fatty acids were measured. In addition, FOS+GOS- or water-treated mice were also exposed to chronic psychosocial stress, and behavior, immune, and microbiota parameters were assessed. RESULTS Chronic prebiotic FOS+GOS treatment exhibited both antidepressant and anxiolytic effects. Moreover, the administration of GOS and the FOS+GOS combination reduced stress-induced corticosterone release. Prebiotics modified specific gene expression in the hippocampus and hypothalamus. Regarding short-chain fatty acid concentrations, prebiotic administration increased cecal acetate and propionate and reduced isobutyrate concentrations, changes that correlated significantly with the positive effects seen on behavior. Moreover, FOS+GOS reduced chronic stress-induced elevations in corticosterone and proinflammatory cytokine levels and depression-like and anxiety-like behavior in addition to normalizing the effects of stress on the microbiota. CONCLUSIONS Taken together, these data strongly suggest a beneficial role of prebiotic treatment for stress-related behaviors. These findings strengthen the evidence base supporting therapeutic targeting of the gut microbiota for brain-gut axis disorders, opening new avenues in the field of nutritional neuropsychopharmacology.
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Affiliation(s)
| | - Silvia Arboleya
- APC Microbiome Institute, University College Cork, Cork; Teagasc Food Research Centre, Biosciences Department, Moorepark, Fermoy, Ireland
| | | | - Veronica L Peterson
- APC Microbiome Institute, University College Cork, Cork; Department of Psychiatry and Neurobehavioral Science, University College Cork, Cork; Department of Anatomy and Neuroscience, University College Cork, Cork
| | - Kiera Murphy
- Teagasc Food Research Centre, Biosciences Department, Moorepark, Fermoy, Ireland
| | - Gerard Clarke
- APC Microbiome Institute, University College Cork, Cork
| | - Catherine Stanton
- APC Microbiome Institute, University College Cork, Cork; Teagasc Food Research Centre, Biosciences Department, Moorepark, Fermoy, Ireland
| | | | - John F Cryan
- APC Microbiome Institute, University College Cork, Cork; Department of Psychiatry and Neurobehavioral Science, University College Cork, Cork; Department of Anatomy and Neuroscience, University College Cork, Cork.
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137
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Kelly JR, Minuto C, Cryan JF, Clarke G, Dinan TG. Cross Talk: The Microbiota and Neurodevelopmental Disorders. Front Neurosci 2017; 11:490. [PMID: 28966571 PMCID: PMC5605633 DOI: 10.3389/fnins.2017.00490] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/17/2017] [Indexed: 12/11/2022] Open
Abstract
Humans evolved within a microbial ecosystem resulting in an interlinked physiology. The gut microbiota can signal to the brain via the immune system, the vagus nerve or other host-microbe interactions facilitated by gut hormones, regulation of tryptophan metabolism and microbial metabolites such as short chain fatty acids (SCFA), to influence brain development, function and behavior. Emerging evidence suggests that the gut microbiota may play a role in shaping cognitive networks encompassing emotional and social domains in neurodevelopmental disorders. Drawing upon pre-clinical and clinical evidence, we review the potential role of the gut microbiota in the origins and development of social and emotional domains related to Autism spectrum disorders (ASD) and schizophrenia. Small preliminary clinical studies have demonstrated gut microbiota alterations in both ASD and schizophrenia compared to healthy controls. However, we await the further development of mechanistic insights, together with large scale longitudinal clinical trials, that encompass a systems level dimensional approach, to investigate whether promising pre-clinical and initial clinical findings lead to clinical relevance.
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Affiliation(s)
- John R Kelly
- Department of Psychiatry and Neurobehavioural Science, University College CorkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | - Chiara Minuto
- Department of Psychiatry and Neurobehavioural Science, University College CorkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | - John F Cryan
- APC Microbiome Institute, University College CorkCork, Ireland.,Department of Anatomy and Neuroscience, University College CorkCork, Ireland
| | - Gerard Clarke
- Department of Psychiatry and Neurobehavioural Science, University College CorkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
| | - Timothy G Dinan
- Department of Psychiatry and Neurobehavioural Science, University College CorkCork, Ireland.,APC Microbiome Institute, University College CorkCork, Ireland
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138
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Hoban AE, Stilling RM, M Moloney G, Moloney RD, Shanahan F, Dinan TG, Cryan JF, Clarke G. Microbial regulation of microRNA expression in the amygdala and prefrontal cortex. MICROBIOME 2017; 5:102. [PMID: 28838324 PMCID: PMC5571609 DOI: 10.1186/s40168-017-0321-3] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 08/01/2017] [Indexed: 05/20/2023]
Abstract
BACKGROUND There is growing evidence for a role of the gut microbiome in shaping behaviour relevant to many psychiatric and neurological disorders. Preclinical studies using germ-free (GF) animals have been essential in contributing to our current understanding of the potential importance of the host microbiome for neurodevelopment and behaviour. In particular, it has been repeatedly demonstrated that manipulation of the gut microbiome modulates anxiety-like behaviours. The neural circuits that underlie anxiety- and fear-related behaviours are complex and heavily depend on functional communication between the amygdala and prefrontal cortex (PFC). Previously, we have shown that the transcriptional networks within the amygdala and PFC of GF mice are altered. MicroRNAs (miRNAs) act through translational repression to control gene translation and have also been implicated in anxiety-like behaviours. However, it is unknown whether these features of host post-transcriptional machinery are also recruited by the gut microbiome to exert control over CNS transcriptional networks. RESULTS We conducted Illumina® next-generation sequencing (NGS) in the amygdala and PFC of conventional, GF and germ-free colonized mice (exGF). We found a large proportion of miRNAs to be dysregulated in GF animals in both brain regions (103 in the amygdala and 31 in the PFC). Additionally, colonization of GF mice normalized some of the noted alterations. Next, we used a complementary approach to GF by manipulating the adult rat microbiome with an antibiotic cocktail to deplete the gut microbiota and found that this strategy also impacted the expression of relevant miRNAs. CONCLUSION These results suggest that the microbiome is necessary for appropriate regulation of miRNA expression in brain regions implicated in anxiety-like behaviours.
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Affiliation(s)
- Alan E Hoban
- APC Microbiome Institute, University College Cork, Cork City, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork City, Ireland
| | - Roman M Stilling
- APC Microbiome Institute, University College Cork, Cork City, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork City, Ireland
| | - Gerard M Moloney
- Department of Anatomy and Neuroscience, University College Cork, Cork City, Ireland
| | - Rachel D Moloney
- APC Microbiome Institute, University College Cork, Cork City, Ireland
- Department of Psychiatry and Neurobehavioural Science, Biosciences Institute, University College Cork, Room 1.15, College Road, Cork City, Ireland
| | - Fergus Shanahan
- APC Microbiome Institute, University College Cork, Cork City, Ireland
| | - Timothy G Dinan
- APC Microbiome Institute, University College Cork, Cork City, Ireland
- Department of Psychiatry and Neurobehavioural Science, Biosciences Institute, University College Cork, Room 1.15, College Road, Cork City, Ireland
| | - John F Cryan
- APC Microbiome Institute, University College Cork, Cork City, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork City, Ireland
| | - Gerard Clarke
- APC Microbiome Institute, University College Cork, Cork City, Ireland.
- Department of Psychiatry and Neurobehavioural Science, Biosciences Institute, University College Cork, Room 1.15, College Road, Cork City, Ireland.
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139
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Cenit MC, Sanz Y, Codoñer-Franch P. Influence of gut microbiota on neuropsychiatric disorders. World J Gastroenterol 2017; 23:5486-5498. [PMID: 28852308 PMCID: PMC5558112 DOI: 10.3748/wjg.v23.i30.5486] [Citation(s) in RCA: 223] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/08/2017] [Accepted: 07/04/2017] [Indexed: 02/06/2023] Open
Abstract
The last decade has witnessed a growing appreciation of the fundamental role played by an early assembly of a diverse and balanced gut microbiota and its subsequent maintenance for future health of the host. Gut microbiota is currently viewed as a key regulator of a fluent bidirectional dialogue between the gut and the brain (gut-brain axis). A number of preclinical studies have suggested that the microbiota and its genome (microbiome) may play a key role in neurodevelopmental and neurodegenerative disorders. Furthermore, alterations in the gut microbiota composition in humans have also been linked to a variety of neuropsychiatric conditions, including depression, autism and Parkinson’s disease. However, it is not yet clear whether these changes in the microbiome are causally related to such diseases or are secondary effects thereof. In this respect, recent studies in animals have indicated that gut microbiota transplantation can transfer a behavioral phenotype, suggesting that the gut microbiota may be a modifiable factor modulating the development or pathogenesis of neuropsychiatric conditions. Further studies are warranted to establish whether or not the findings of preclinical animal experiments can be generalized to humans. Moreover, although different communication routes between the microbiota and brain have been identified, further studies must elucidate all the underlying mechanisms involved. Such research is expected to contribute to the design of strategies to modulate the gut microbiota and its functions with a view to improving mental health, and thus provide opportunities to improve the management of psychiatric diseases. Here, we review the evidence supporting a role of the gut microbiota in neuropsychiatric disorders and the state of the art regarding the mechanisms underlying its contribution to mental illness and health. We also consider the stages of life where the gut microbiota is more susceptible to the effects of environmental stressors, and the possible microbiota-targeted intervention strategies that could improve health status and prevent psychiatric disorders in the near future.
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140
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Abstract
The microbiota is increasingly recognized for its ability to influence the development and function of the nervous system and several complex host behaviors. In this review, we discuss emerging roles for the gut microbiota in modulating host social and communicative behavior, stressor-induced behavior, and performance in learning and memory tasks. We summarize effects of the microbiota on host neurophysiology, including brain microstructure, gene expression, and neurochemical metabolism across regions of the amygdala, hippocampus, frontal cortex, and hypothalamus. We further assess evidence linking dysbiosis of the gut microbiota to neurobehavioral diseases, such as autism spectrum disorder and major depression, drawing upon findings from animal models and human trials. Finally, based on increasing associations between the microbiota, neurophysiology, and behavior, we consider whether investigating mechanisms underlying the microbiota-gut-brain axis could lead to novel approaches for treating particular neurological conditions.
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Affiliation(s)
- Helen E Vuong
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095;
| | - Jessica M Yano
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095;
| | - Thomas C Fung
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095;
| | - Elaine Y Hsiao
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095;
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141
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Moloney GM, O'Leary OF, Salvo-Romero E, Desbonnet L, Shanahan F, Dinan TG, Clarke G, Cryan JF. Microbial regulation of hippocampal miRNA expression: Implications for transcription of kynurenine pathway enzymes. Behav Brain Res 2017; 334:50-54. [PMID: 28736331 DOI: 10.1016/j.bbr.2017.07.026] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 01/15/2023]
Abstract
Increasing evidence points to a functional role of the enteric microbiota in brain development, function and behaviour including the regulation of transcriptional activity in the hippocampus. Changes in CNS miRNA expression may reflect the colonisation status of the gut. Given the pivotal impact of miRNAs on gene expression, our study was based on the hypothesis that gene expression would also be altered in the germ-free state in the hippocampus. We measured miRNAs in the hippocampus of Germ free (GF), conventional (C) and Germ free colonised (exGF) Swiss Webster mice. miRNAs were selected for follow up based on significant differences in expression between groups according to sex and colonisation status. The expression of miR-294-5p was increased in male germ free animals and was normalised following colonisation. Targets of the differentially expressed miRNAs were over-represented in the kynurenine pathway. We show that the microbiota modulates the expression of miRNAs associated with kynurenine pathway metabolism and, demonstrate that the gut microbiota regulates the expression of kynurenine pathway genes in the hippocampus. We also show a sex-specific role for the microbiota in the regulation of miR-294-5p expression in the hippocampus. The gut microbiota plays an important role in modulating small RNAs that influence hippocampal gene expression, a process critical to hippocampal development.
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Affiliation(s)
- Gerard M Moloney
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland.
| | - Olivia F O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland.
| | - Eloisa Salvo-Romero
- Laboratory of Neuro-Immuno-Gastroenterology, Digestive Diseases Research Unit, Vall d'Hebron Institut de Recerca, Department of Gastroenterology, Hospital Universitario Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.
| | - Lieve Desbonnet
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.
| | - Fergus Shanahan
- APC Microbiome Institute, University College Cork, Cork, Ireland.
| | - Timothy G Dinan
- Department of Psychiatry and Neurobehavioural Science, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland.
| | - Gerard Clarke
- Department of Psychiatry and Neurobehavioural Science, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland.
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; APC Microbiome Institute, University College Cork, Cork, Ireland.
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142
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Luczynski P, Tramullas M, Viola M, Shanahan F, Clarke G, O'Mahony S, Dinan TG, Cryan JF. Microbiota regulates visceral pain in the mouse. eLife 2017. [PMID: 28629511 PMCID: PMC5478269 DOI: 10.7554/elife.25887] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The perception of visceral pain is a complex process involving the spinal cord and higher order brain structures. Increasing evidence implicates the gut microbiota as a key regulator of brain and behavior, yet it remains to be determined if gut bacteria play a role in visceral sensitivity. We used germ-free mice (GF) to assess visceral sensitivity, spinal cord gene expression and pain-related brain structures. GF mice displayed visceral hypersensitivity accompanied by increases in Toll-like receptor and cytokine gene expression in the spinal cord, which were normalized by postnatal colonization with microbiota from conventionally colonized (CC). In GF mice, the volumes of the anterior cingulate cortex (ACC) and periaqueductal grey, areas involved in pain processing, were decreased and enlarged, respectively, and dendritic changes in the ACC were evident. These findings indicate that the gut microbiota is required for the normal visceral pain sensation. DOI:http://dx.doi.org/10.7554/eLife.25887.001 The human gut is home to over 100 trillion microbes collectively known as the gut microbiota. These microbes help us to digest food and absorb the nutrients effectively. A diverse and stable community of gut microbes is believed to be important for good health. Recently, it has also become clear that the microbiota can also influence the brain and how we behave. For example, many studies suggest that gut microbiota can alter how an individual perceives pain, but it is not clear how this works. Rodents are often used in experiments as models of human biology. One of the most frequently used rodent models in studies of gut microbes is the “germ-free” mouse. These mice grow up in laboratory environments that are completely free of microbes, making it possible to study how having no gut microbes affects the health and behaviour of the mice. Luczynski, Tramullas et al. used germ-free mice to study how the gut microbiota influences an animal’s sensitivity to pain. The experiments show that, compared to mice with normal gut microbiota, the germ-free mice were more sensitive to pain from internal organs especially the gut. These mice also produced larger amounts of specific proteins involved in immune responses, which contributed to the animal’s increased sensitivity to pain. Allowing the germ-free mice to be colonised with gut microbes could reverse these changes. The experiments also show that the germ-free mice had changes in the size of two areas of the brain involved in sensing pain: an area called the anterior cingulate cortex was smaller, while the periaqueductal grey region was enlarged. There were also differences in individual nerve cells within the anterior cingulate cortex compared to normal mice. The findings of Luczynski, Tramullas et al. reinforce the idea that the gut microbiota is involved in the sensation of pain from internal organs, and show that hypersensitivity to this form of pain can be reversed later in life by colonising the gut with microbes. Continuing to study the impact of microbes on this type of pain could aid the development of new therapies for the treatment of pain disorders in humans. DOI:http://dx.doi.org/10.7554/eLife.25887.002
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Affiliation(s)
| | - Monica Tramullas
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Maria Viola
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Fergus Shanahan
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - Siobhain O'Mahony
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Timothy G Dinan
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - John F Cryan
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
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143
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Thomas S, Izard J, Walsh E, Batich K, Chongsathidkiet P, Clarke G, Sela DA, Muller AJ, Mullin JM, Albert K, Gilligan JP, DiGuilio K, Dilbarova R, Alexander W, Prendergast GC. The Host Microbiome Regulates and Maintains Human Health: A Primer and Perspective for Non-Microbiologists. Cancer Res 2017; 77:1783-1812. [PMID: 28292977 PMCID: PMC5392374 DOI: 10.1158/0008-5472.can-16-2929] [Citation(s) in RCA: 215] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/19/2016] [Accepted: 12/21/2016] [Indexed: 02/07/2023]
Abstract
Humans consider themselves discrete autonomous organisms, but recent research is rapidly strengthening the appreciation that associated microorganisms make essential contributions to human health and well being. Each person is inhabited and also surrounded by his/her own signature microbial cloud. A low diversity of microorganisms is associated with a plethora of diseases, including allergy, diabetes, obesity, arthritis, inflammatory bowel diseases, and even neuropsychiatric disorders. Thus, an interaction of microorganisms with the host immune system is required for a healthy body. Exposure to microorganisms from the moment we are born and appropriate microbiome assembly during childhood are essential for establishing an active immune system necessary to prevent disease later in life. Exposure to microorganisms educates the immune system, induces adaptive immunity, and initiates memory B and T cells that are essential to combat various pathogens. The correct microbial-based education of immune cells may be critical in preventing the development of autoimmune diseases and cancer. This review provides a broad overview of the importance of the host microbiome and accumulating knowledge of how it regulates and maintains a healthy human system. Cancer Res; 77(8); 1783-812. ©2017 AACR.
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Affiliation(s)
- Sunil Thomas
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania.
| | - Jacques Izard
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Emily Walsh
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts
| | - Kristen Batich
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- Department of Surgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Pakawat Chongsathidkiet
- Department of Neurosurgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- Department of Surgery, Duke Brain Tumor Immunotherapy Program, Duke University Medical Center, Durham, North Carolina
- Department of Pathology, Duke University Medical Center, Durham, North Carolina
| | - Gerard Clarke
- Department of Psychiatry and Neurobehavioural Science, APC Microbiome Institute University College Cork, Cork, Ireland
| | - David A Sela
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts
- Center for Microbiome Research, University of Massachusetts Medical School, Worcester, Massachusetts
| | | | - James M Mullin
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania
| | - Korin Albert
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts
- Department of Food Science, University of Massachusetts, Amherst, Massachusetts
| | - John P Gilligan
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania
| | | | - Rima Dilbarova
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania
| | - Walker Alexander
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania
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144
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The Central Nervous System and the Gut Microbiome. Cell 2017; 167:915-932. [PMID: 27814521 DOI: 10.1016/j.cell.2016.10.027] [Citation(s) in RCA: 852] [Impact Index Per Article: 121.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/14/2016] [Accepted: 10/16/2016] [Indexed: 12/11/2022]
Abstract
Neurodevelopment is a complex process governed by both intrinsic and extrinsic signals. While historically studied by researching the brain, inputs from the periphery impact many neurological conditions. Indeed, emerging data suggest communication between the gut and the brain in anxiety, depression, cognition, and autism spectrum disorder (ASD). The development of a healthy, functional brain depends on key pre- and post-natal events that integrate environmental cues, such as molecular signals from the gut. These cues largely originate from the microbiome, the consortium of symbiotic bacteria that reside within all animals. Research over the past few years reveals that the gut microbiome plays a role in basic neurogenerative processes such as the formation of the blood-brain barrier, myelination, neurogenesis, and microglia maturation and also modulates many aspects of animal behavior. Herein, we discuss the biological intersection of neurodevelopment and the microbiome and explore the hypothesis that gut bacteria are integral contributors to development and function of the nervous system and to the balance between mental health and disease.
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145
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Moya-Pérez A, Luczynski P, Renes IB, Wang S, Borre Y, Anthony Ryan C, Knol J, Stanton C, Dinan TG, Cryan JF. Intervention strategies for cesarean section-induced alterations in the microbiota-gut-brain axis. Nutr Rev 2017; 75:225-240. [PMID: 28379454 PMCID: PMC5410982 DOI: 10.1093/nutrit/nuw069] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Microbial colonization of the gastrointestinal tract is an essential process that modulates host physiology and immunity. Recently, researchers have begun to understand how and when these microorganisms colonize the gut and the early-life factors that impact their natural ecological establishment. The vertical transmission of maternal microbes to the offspring is a critical factor for host immune and metabolic development. Increasing evidence also points to a role in the wiring of the gut-brain axis. This process may be altered by various factors such as mode of delivery, gestational age at birth, the use of antibiotics in early life, infant feeding, and hygiene practices. In fact, these early exposures that impact the intestinal microbiota have been associated with the development of diseases such as obesity, type 1 diabetes, asthma, allergies, and even neurodevelopmental disorders. The present review summarizes the impact of cesarean birth on the gut microbiome and the health status of the developing infant and discusses possible preventative and restorative strategies to compensate for early-life microbial perturbations.
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Affiliation(s)
- Angela Moya-Pérez
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
| | - Pauline Luczynski
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
| | - Ingrid B. Renes
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
| | - Shugui Wang
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
| | - Yuliya Borre
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
| | - C. Anthony Ryan
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
| | - Jan Knol
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
| | - Catherine Stanton
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
| | - Timothy G. Dinan
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
| | - John F. Cryan
- A. Moya-Pérez, P. Luczynski, Y. Borre, C.A. Ryan, C. Stanton, T.G. Dinan, and J.F. Cryan are with the APC Microbiome Institute; C.A. Ryan is with the Department of Paediatrics and Child Health; T.G. Dinan is with the Department of Psychiatry and Neurobehavioural Science; and J.F. Cryan is with the Department of Anatomy and Neuroscience; University College Cork, Cork, Ireland. I.B. Renes and J. Knol are with Nutricia Research, Utrecht, the Netherlands. S. Wang is with Nutricia Research, Singapore. J. Knol is with the Laboratory of Microbiology, Wageningen University, Wageningen, the Netherlands. C. Stanton is with the Teagasc Moorepark Food Research Centre, Fermoy, Cork, Ireland
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146
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Foster JA, Rinaman L, Cryan JF. Stress & the gut-brain axis: Regulation by the microbiome. Neurobiol Stress 2017; 7:124-136. [PMID: 29276734 PMCID: PMC5736941 DOI: 10.1016/j.ynstr.2017.03.001] [Citation(s) in RCA: 587] [Impact Index Per Article: 83.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/16/2017] [Accepted: 03/02/2017] [Indexed: 12/11/2022] Open
Abstract
The importance of the gut–brain axis in regulating stress-related responses has long been appreciated. More recently, the microbiota has emerged as a key player in the control of this axis, especially during conditions of stress provoked by real or perceived homeostatic challenge. Diet is one of the most important modifying factors of the microbiota-gut-brain axis. The routes of communication between the microbiota and brain are slowly being unravelled, and include the vagus nerve, gut hormone signaling, the immune system, tryptophan metabolism, and microbial metabolites such as short chain fatty acids. The importance of the early life gut microbiota in shaping later health outcomes also is emerging. Results from preclinical studies indicate that alterations of the early microbial composition by way of antibiotic exposure, lack of breastfeeding, birth by Caesarean section, infection, stress exposure, and other environmental influences - coupled with the influence of host genetics - can result in long-term modulation of stress-related physiology and behaviour. The gut microbiota has been implicated in a variety of stress-related conditions including anxiety, depression and irritable bowel syndrome, although this is largely based on animal studies or correlative analysis in patient populations. Additional research in humans is sorely needed to reveal the relative impact and causal contribution of the microbiome to stress-related disorders. In this regard, the concept of psychobiotics is being developed and refined to encompass methods of targeting the microbiota in order to positively impact mental health outcomes. At the 2016 Neurobiology of Stress Workshop in Newport Beach, CA, a group of experts presented the symposium “The Microbiome: Development, Stress, and Disease”. This report summarizes and builds upon some of the key concepts in that symposium within the context of how microbiota might influence the neurobiology of stress.
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Affiliation(s)
- Jane A Foster
- Department of Psychiatry & Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Linda Rinaman
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
| | - John F Cryan
- APC Microbiome Institute, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
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147
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Exercise Modifies the Gut Microbiota with Positive Health Effects. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:3831972. [PMID: 28357027 PMCID: PMC5357536 DOI: 10.1155/2017/3831972] [Citation(s) in RCA: 282] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 12/18/2016] [Accepted: 01/05/2017] [Indexed: 12/26/2022]
Abstract
The human gastrointestinal tract (GIT) is inhabited by a wide cluster of microorganisms that play protective, structural, and metabolic functions for the intestinal mucosa. Gut microbiota is involved in the barrier functions and in the maintenance of its homeostasis. It provides nutrients, participates in the signaling network, regulates the epithelial development, and affects the immune system. Considering the microbiota ability to respond to homeostatic and physiological changes, some researchers proposed that it can be seen as an endocrine organ. Evidence suggests that different factors can determine changes in the gut microbiota. These changes can be both quantitative and qualitative resulting in variations of the composition and metabolic activity of the gut microbiota which, in turn, can affect health and different disease processes. Recent studies suggest that exercise can enhance the number of beneficial microbial species, enrich the microflora diversity, and improve the development of commensal bacteria. All these effects are beneficial for the host, improving its health status. In this paper, we intend to shed some light over the recent knowledge of the role played by exercise as an environmental factor in determining changes in microbial composition and how these effects could provide benefits to health and disease prevention.
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148
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Vuong HE, Hsiao EY. Emerging Roles for the Gut Microbiome in Autism Spectrum Disorder. Biol Psychiatry 2017; 81:411-423. [PMID: 27773355 PMCID: PMC5285286 DOI: 10.1016/j.biopsych.2016.08.024] [Citation(s) in RCA: 326] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/28/2016] [Accepted: 08/18/2016] [Indexed: 01/16/2023]
Abstract
Autism spectrum disorder (ASD) is a serious neurodevelopmental disorder that affects one in 45 children in the United States, with a similarly striking prevalence in countries around the world. However, mechanisms underlying its etiology and manifestations remain poorly understood. Although ASD is diagnosed based on the presence and severity of impaired social communication and repetitive behavior, immune dysregulation and gastrointestinal issues are common comorbidities. The microbiome is an integral part of human physiology; recent studies show that changes in the gut microbiota can modulate gastrointestinal physiology, immune function, and even behavior. Links between particular bacteria from the indigenous gut microbiota and phenotypes relevant to ASD raise the important question of whether microbial dysbiosis plays a role in the development or presentation of ASD symptoms. Here we review reports of microbial dysbiosis in ASD. We further discuss potential effects of the microbiota on ASD-associated symptoms, drawing on signaling mechanisms for reciprocal interactions among the microbiota, immunity, gut function, and behavior. In addition, we discuss recent findings supporting a role for the microbiome as an interface between environmental and genetic risk factors that are associated with ASD. These studies highlight the integration of pathways across multiple body systems that together can impact brain and behavior and suggest that changes in the microbiome may contribute to symptoms of neurodevelopmental disease.
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Affiliation(s)
- Helen E. Vuong
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Elaine Y. Hsiao
- Department of Integrative Biology & Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA,Correspondence to: ; 610 Charles E. Young Drive MSB 3825A; Los Angeles CA 90095; 310-825-0228
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149
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Dinan TG, Cryan JF. Gut instincts: microbiota as a key regulator of brain development, ageing and neurodegeneration. J Physiol 2017; 595:489-503. [PMID: 27641441 PMCID: PMC5233671 DOI: 10.1113/jp273106] [Citation(s) in RCA: 444] [Impact Index Per Article: 63.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/13/2016] [Indexed: 12/16/2022] Open
Abstract
There is a growing realisation that the gut-brain axis and its regulation by the microbiota may play a key role in the biological and physiological basis of neurodevelopmental, age-related and neurodegenerative disorders. The routes of communication between the microbiota and brain are being unravelled and include the vagus nerve, gut hormone signalling, the immune system, tryptophan metabolism or by way of microbial metabolites such as short chain fatty acids. The importance of early life gut microbiota in shaping future health outcomes is also emerging. Disturbances of this composition by way of antibiotic exposure, lack of breastfeeding, infection, stress and the environmental influences coupled with the influence of host genetics can result in long-term effects on physiology and behaviour, at least in animal models. It is also worth noting that mode of delivery at birth influences microbiota composition with those born by Caesarean section having a distinctly different microbiota in early life to those born per vaginum. At the other extreme of life, ageing is associated with a narrowing in microbial diversity and healthy ageing correlates with a diverse microbiome. Recently, the gut microbiota has been implicated in a variety of conditions including depression, autism, schizophrenia and Parkinson's disease. There is still considerable debate as to whether or not the gut microbiota changes are core to the pathophysiology of such conditions or are merely epiphenomenal. It is plausible that such neuropsychiatric disorders might be treated in the future by targeting the microbiota either by microbiota transplantation, antibiotics or psychobiotics.
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Affiliation(s)
- Timothy G. Dinan
- APC Microbiome InstituteUniversity College CorkIreland
- Department of Psychiatry and Neurobehavioural ScienceUniversity College CorkIreland
| | - John F. Cryan
- APC Microbiome InstituteUniversity College CorkIreland
- Department of Anatomy and NeuroscienceUniversity College CorkIreland
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Kynurenine pathway metabolism and the microbiota-gut-brain axis. Neuropharmacology 2017; 112:399-412. [DOI: 10.1016/j.neuropharm.2016.07.002] [Citation(s) in RCA: 311] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 06/30/2016] [Accepted: 07/04/2016] [Indexed: 02/07/2023]
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