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McVey Neufeld KA, Luczynski P, Dinan TG, Cryan JF. Reframing the Teenage Wasteland: Adolescent Microbiota-Gut-Brain Axis. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2016; 61:214-21. [PMID: 27254413 PMCID: PMC4794958 DOI: 10.1177/0706743716635536] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Human adolescence is arguably one of the most challenging periods of development. The young adult is exposed to a variety of stressors and environmental stimuli on a backdrop of significant physiological change and development, which is especially apparent in the brain. It is therefore unsurprising that many psychiatric disorders are first observable during this time. The human intestine is inhabited by trillions of microorganisms, and evidence from both preclinical and clinical research focusing on the established microbiota-gut-brain axis suggests that the etiology and pathophysiology of psychiatric disorders may be influenced by intestinal dysbiosis. Provocatively, many if not all of the challenges faced by the developing teen have a documented impact on these intestinal commensal microbiota. In this review, we briefly summarize what is known about the developing adolescent brain and intestinal microbiota, discuss recent research investigating the microbiota-gut-brain axis during puberty, and propose that pre- and probiotics may prove useful in both the prevention and treatment of psychiatric disorders specifically benefitting the young adult.
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Affiliation(s)
| | | | - Timothy G Dinan
- APC Microbiome Institute, University College Cork, Cork, Ireland Department of Psychiatry, 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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Rea K, Dinan TG, Cryan JF. The microbiome: A key regulator of stress and neuroinflammation. Neurobiol Stress 2016; 4:23-33. [PMID: 27981187 PMCID: PMC5146205 DOI: 10.1016/j.ynstr.2016.03.001] [Citation(s) in RCA: 283] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/03/2016] [Accepted: 03/03/2016] [Indexed: 02/06/2023] Open
Abstract
There is a growing emphasis on the relationship between the complexity and diversity of the microorganisms that inhabit our gut (human gastrointestinal microbiota) and health/disease, including brain health and disorders of the central nervous system. The microbiota-gut-brain axis is a dynamic matrix of tissues and organs including the brain, glands, gut, immune cells and gastrointestinal microbiota that communicate in a complex multidirectional manner to maintain homeostasis. Changes in this environment can lead to a broad spectrum of physiological and behavioural effects including hypothalamic-pituitary-adrenal (HPA) axis activation, and altered activity of neurotransmitter systems and immune function. While an appropriate, co-ordinated physiological response, such as an immune or stress response are necessary for survival, a dysfunctional response can be detrimental to the host contributing to the development of a number of CNS disorders. In this review, the involvement of the gastrointestinal microbiota in stress-mediated and immune-mediated modulation of neuroendocrine, immune and neurotransmitter systems and the consequential behaviour is considered. We also focus on the mechanisms by which commensal gut microbiota can regulate neuroinflammation and further aim to exploit our understanding of their role in stress-related disorders as a consequence of neuroinflammatory processes.
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Affiliation(s)
- Kieran Rea
- APC Microbiome Institute, 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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Quigley EMM. Overlapping irritable bowel syndrome and inflammatory bowel disease: less to this than meets the eye? Therap Adv Gastroenterol 2016; 9:199-212. [PMID: 26929782 PMCID: PMC4749858 DOI: 10.1177/1756283x15621230] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Though distinct in terms of pathology, natural history and therapeutic approach, irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) have some features in common. These include shared symptomatology and largely similar demographics. However, in most instances, clinical presentation, together with laboratory, imaging and endoscopic findings will readily permit the differentiation of active IBD from IBS. More problematic is the situation where a subject with IBD, in apparent remission, continues to complain of symptoms which, in aggregate, satisfy commonly employed criteria for the diagnosis of IBS. Access to methodologies, such the assay for levels of calprotectin in feces, now allows identification of ongoing inflammation in some such individuals and prompts appropriate therapy. More challenging is the IBD patient with persisting symptoms and no detectable evidence of inflammation; is this coincident IBS, IBS triggered by IBD or an even more subtle level of IBD activity unrecognized by available laboratory or imaging methods? Arguments can be advanced for each of these proposals; lacking definitive data, this issue remains unresolved. The occurrence of IBS-type symptoms in the IBD patient, together with some data suggesting a very subtle level of 'inflammation' or 'immune activation' in IBS, raises other questions: is IBS a prodromal form of IBD; and are IBS and IBD part of the spectrum of the same disease? All of the available evidence indicates that the answer to both these questions should be a resounding 'no'. Indeed, the whole issue of overlap between IBS and IBD should be declared moot given their differing pathophysiologies, contrasting natural histories and divergent treatment paths. The limited symptom repertoire of the gastrointestinal tract may well be fundamental to the apparent confusion that has, of late, bedeviled this area.
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Abstract
Irritable bowel syndrome (IBS) is a multifactorial functional disorder with no clearly defined etiology or pathophysiology. Modern culture-independent techniques have improved the understanding of the gut microbiota’s composition and demonstrated that an altered gut microbiota profile might be found in at least some subgroups of IBS patients. Research on IBS from a microbial perspective is gaining momentum and advancing. This review will therefore highlight potential links between the gut microbiota and IBS by discussing the current knowledge of the gut microbiota; it will also illustrate bacterial-host interactions and how alterations to these interactions could exacerbate, induce or even help alleviate IBS.
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Affiliation(s)
- Sean M P Bennet
- Departments of Internal Medicine and Clinical Nutrition, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lena Ohman
- Departments of Internal Medicine and Clinical Nutrition, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Magnus Simren
- Departments of Internal Medicine and Clinical Nutrition, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Anitha M, Reichardt F, Tabatabavakili S, Nezami BG, Chassaing B, Mwangi S, Vijay-Kumar M, Gewirtz A, Srinivasan S. Intestinal dysbiosis contributes to the delayed gastrointestinal transit in high-fat diet fed mice. Cell Mol Gastroenterol Hepatol 2016; 2:328-339. [PMID: 27446985 PMCID: PMC4945127 DOI: 10.1016/j.jcmgh.2015.12.008] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND & AIMS High-fat diet (HFD) feeding is associated with gastrointestinal motility disorders. We recently reported delayed colonic motility in mice fed a HFD mice for 11 weeks. In this study, we investigated the contributing role of gut microbiota in HFD-induced gut dysmotility. METHODS Male C57BL/6 mice were fed a HFD (60% kcal fat) or a regular/control diet (RD) (18% kcal fat) for 13 weeks. Serum and fecal endotoxin levels were measured, and relative amounts of specific gut bacteria in the feces assessed by real time PCR. Intestinal transit was measured by fluorescent-labeled marker and bead expulsion test. Enteric neurons were assessed by immunostaining. Oligofructose (OFS) supplementation with RD or HFD for 5 weeks was also studied. In vitro studies were performed using primary enteric neurons and an enteric neuronal cell line. RESULTS HFD-fed mice had reduced numbers of enteric nitrergic neurons and exhibited delayed gastrointestinal transit compared to RD-fed mice. HFD-fed mice had higher fecal Firmicutes and Escherichia coli and lower Bacteroidetes compared to RD-fed mice. OFS supplementation protected against enteric nitrergic neurons loss in HFD-fed mice, and improved intestinal transit time. OFS supplementation resulted in a reductions in fecal Firmicutes and Escherichia coli and serum endotoxin levels. In vitro, palmitate activation of TLR4 induced enteric neuronal apoptosis in a p-JNK1 dependent pathway. This apoptosis was prevented by a JNK inhibitor and in neurons from TLR4-/- mice. CONCLUSIONS Together our data suggest that intestinal dysbiosis in HFD fed mice contribute to the delayed intestinal motility by inducing a TLR4-dependant neuronal loss. Manipulation of gut microbiota with OFS improved intestinal motility in HFD mice.
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Affiliation(s)
- Mallappa Anitha
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - François Reichardt
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia
| | - Sahar Tabatabavakili
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia
| | - Behtash Ghazi Nezami
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia
| | - Benoit Chassaing
- Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia
| | - Simon Mwangi
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia
| | - Matam Vijay-Kumar
- Department of Nutritional Sciences & Medicine, The Pennsylvania State University, University Park, Pennsylvania
| | - Andrew Gewirtz
- Center for Inflammation, Immunity and Infection, Institute for Biomedical Sciences, Georgia State University, Atlanta, Georgia
| | - Shanthi Srinivasan
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia,Correspondence Address correspondence to: Shanthi Srinivasan, MD, Division of Digestive Diseases, Whitehead Biomedical Research Building, 615 Michael Street, Suite 201A, Atlanta, Georgia 30322. fax: (404) 727-5767.Division of Digestive DiseasesWhitehead Biomedical Research Building615 Michael StreetSuite 201AAtlantaGeorgia 30322
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Xu WL, Lu G, Liang SJ, Wu XL, Pei LX, Geng H, Ning HX, Sun JH. Short chain fatty acids mediated flora-host interaction and irritable bowel syndrome. Shijie Huaren Xiaohua Zazhi 2015; 23:5815-5822. [DOI: 10.11569/wcjd.v23.i36.5815] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Intestinal flora has proved to be closely related to the onset of irritable bowel syndrome (IBS). Short chain fatty acids (SCFAs) are the main product of flora metabolism as well as important messenger molecules in the gut, playing a role in maintaining the stability of microorganism community structure and in regulating intestinal immune response, motility and the epithelial barrier. Flora imbalance in IBS patients has a direct impact on the microbiota-SCFAs-intestinal epithelial cells signal pathway, which results in low-grade inflammation, increased intestinal permeability and abnormality of motility. Studying the role SCFA plays in the pathogenesis of IBS can expand our understanding of this disease and provide a new strategy for therapy.
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Abstract
Although probiotics have been used for many years by those who suffer from what would now be defined as irritable bowel syndrome (IBS), a scientific rationale for their use in this indication and clinical evidence to support their benefits have only emerged very recently. Evidence to support considering strategies, such as probiotics, that modulate the gut microbiome, in IBS, has been provided by laboratory studies implicating the microbiome and the host response to the enteric microenvironment in IBS, as well as in vitro and in vivo studies demonstrating the ability of various commensal bacteria to influence such relevant functions as motility, visceral sensation, gut barrier integrity, and brain-gut interactions. Clinical studies supporting a role for probiotics in the management of IBS predated such experimental data, and randomized controlled trials of probiotics in IBS continue to be reported. Their interpretation is hampered by the less than optimal quality of many studies; nevertheless, it is apparent that probiotics, as a category, do exert significant effects in IBS. Defining the optimal strain, dose, formulation, and duration of therapy is more challenging given the limitations of available data. There is also an urgent need for appropriately powered and rigorously designed clinical trials of appropriate duration of probiotics in IBS; such studies should also help to define those who are most likely to respond to probiotics. Future laboratory and translational research should attempt to define the mechanism(s) of action of probiotics in IBS and explore the response to bacterial components or products in this common and oftentimes troublesome disorder.
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Affiliation(s)
- Eamonn M M Quigley
- *Division of Gastroenterology and Hepatology and Department of Medicine, Houston Methodist Hospital †Department of Medicine, and Weill Cornell Medical College, Houston, TX
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Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci 2015; 9:392. [PMID: 26528128 PMCID: PMC4604320 DOI: 10.3389/fncel.2015.00392] [Citation(s) in RCA: 617] [Impact Index Per Article: 68.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 09/21/2015] [Indexed: 12/12/2022] Open
Abstract
The emerging links between our gut microbiome and the central nervous system (CNS) are regarded as a paradigm shift in neuroscience with possible implications for not only understanding the pathophysiology of stress-related psychiatric disorders, but also their treatment. Thus the gut microbiome and its influence on host barrier function is positioned to be a critical node within the brain-gut axis. Mounting preclinical evidence broadly suggests that the gut microbiota can modulate brain development, function and behavior by immune, endocrine and neural pathways of the brain-gut-microbiota axis. Detailed mechanistic insights explaining these specific interactions are currently underdeveloped. However, the concept that a "leaky gut" may facilitate communication between the microbiota and these key signaling pathways has gained traction. Deficits in intestinal permeability may underpin the chronic low-grade inflammation observed in disorders such as depression and the gut microbiome plays a critical role in regulating intestinal permeability. In this review we will discuss the possible role played by the gut microbiota in maintaining intestinal barrier function and the CNS consequences when it becomes disrupted. We will draw on both clinical and preclinical evidence to support this concept as well as the key features of the gut microbiota which are necessary for normal intestinal barrier function.
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Affiliation(s)
- John R Kelly
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork Cork, Ireland ; Department of Psychiatry and Neurobehavioural Science, University College Cork Cork, Ireland
| | - Paul J Kennedy
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork Cork, Ireland
| | - John F Cryan
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork Cork, Ireland ; Department of Anatomy and Neuroscience, University College Cork Cork, Ireland
| | - Timothy G Dinan
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork Cork, Ireland ; Department of Psychiatry and Neurobehavioural Science, University College Cork Cork, Ireland
| | - Gerard Clarke
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork Cork, Ireland ; Department of Psychiatry and Neurobehavioural Science, University College Cork Cork, Ireland
| | - Niall P Hyland
- Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork Cork, Ireland ; Department of Pharmacology and Therapeutics, University College Cork Cork, Ireland
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Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci 2015. [DOI: 10.3389/fncel.2015.00392 order by 1-- -] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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60
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Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci 2015. [DOI: 10.3389/fncel.2015.00392 order by 8029-- -] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci 2015. [DOI: 10.3389/fncel.2015.00392 order by 8029-- #] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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62
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Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci 2015. [DOI: 10.3389/fncel.2015.00392 order by 1-- gadu] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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63
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Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci 2015. [DOI: 10.3389/fncel.2015.00392 order by 8029-- awyx] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci 2015. [DOI: 10.3389/fncel.2015.00392 order by 1-- #] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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65
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Kelly JR, Kennedy PJ, Cryan JF, Dinan TG, Clarke G, Hyland NP. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders. Front Cell Neurosci 2015. [DOI: 10.3389/fncel.2015.00392 and 1880=1880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
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Fecal Microbiota in Patients with Irritable Bowel Syndrome Compared with Healthy Controls Using Real-Time Polymerase Chain Reaction: An Evidence of Dysbiosis. Dig Dis Sci 2015; 60:2953-62. [PMID: 25784074 DOI: 10.1007/s10620-015-3607-y] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 02/21/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND Dysbiosis may play a role in irritable bowel syndrome (IBS), hitherto an enigmatic disorder. We evaluated selected fecal microbes in IBS patients and healthy controls (HC). METHODS Fecal 16S rRNA copy number of selected bacteria was studied using qPCR in 47 patients with IBS (Rome III) and 30 HC. RESULTS Of 47 patients, 20 had constipation (IBS-C), 20 diarrhea (IBS-D), and seven unclassified IBS (IBS-U). Relative difference in 16S rRNA copy number of Bifidobacterium (P = 0.042) was lower, while those of Ruminococcus productus-Clostridium coccoides (P = 0.016), Veillonella (P = 0.008), Bacteroides thetaiotamicron (P < 0.001), Pseudomonas aeruginosa (P < 0.001), and Gram-negative bacteria (GNB, P = 0.001) were higher among IBS patients than HC. Number of Lactobacillus (P = 0.002) was lower, while that of Bacteroides thetaiotamicron (P < 0.001) and segmented filamentous bacteria (SFB, P < 0.001) was higher among IBS-D than IBS-C. Numbers of Bacteroides thetaiotamicron (P < 0.001), P. aeruginosa (P < 0.001), and GNB (P < 0.01) were higher among IBS-C and IBS-D than HC. Quantity of SFB was higher among IBS-D (P = 0.011) and lower among IBS-C (P = 0.002) than HC. Number of Veillonella species was higher among IBS-C than HC (P = 0.002). P. aeruginosa was frequently detected among IBS than HC (46/47 [97.9 %] vs. 10/30 [33.3 %], P < 0.001). Abdominal distension (n = 34/47) was associated with higher number of Bacteroides thetaiotamicron, Clostridium coccoides, P. aeruginosa, SFB, and GNB; bloating (n = 22/47) was associated with Clostridium coccoides and GNB. Microbial flora was different among IBS than HC on principal component analysis. CONCLUSION Fecal microbiota was different among IBS than HC, and different sub-types were associated with different microbiota. P. aeruginosa was more frequent and higher in number among IBS patients.
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O'Mahony SM, Clarke G, Dinan TG, Cryan JF. Early-life adversity and brain development: Is the microbiome a missing piece of the puzzle? Neuroscience 2015; 342:37-54. [PMID: 26432952 DOI: 10.1016/j.neuroscience.2015.09.068] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 09/23/2015] [Accepted: 09/25/2015] [Indexed: 12/12/2022]
Abstract
The prenatal and postnatal early-life periods are both dynamic and vulnerable windows for brain development. During these important neurodevelopmental phases, essential processes and structures are established. Exposure to adverse events that interfere with this critical sequence of events confers a high risk for the subsequent emergence of mental illness later in life. It is increasingly accepted that the gastrointestinal microbiota contributes substantially to shaping the development of the central nervous system. Conversely, several studies have shown that early-life events can also impact on this gut community. Due to the bidirectional communication between the gut and the brain, it is possible that aberrant situations affecting either organ in early life can impact on the other. Studies have now shown that deviations from the gold standard trajectory of gut microbiota establishment and development in early life can lead not only to disorders of the gastrointestinal tract but also complex metabolic and immune disorders. These are being extended to disorders of the central nervous system and understanding how the gut microbiome shapes brain and behavior during early life is an important new frontier in neuroscience.
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Affiliation(s)
- S M O'Mahony
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
| | - G Clarke
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - T G Dinan
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
| | - J F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland; Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
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Desbonnet L, Clarke G, Traplin A, O'Sullivan O, Crispie F, Moloney RD, Cotter PD, Dinan TG, Cryan JF. Gut microbiota depletion from early adolescence in mice: Implications for brain and behaviour. Brain Behav Immun 2015; 48:165-73. [PMID: 25866195 DOI: 10.1016/j.bbi.2015.04.004] [Citation(s) in RCA: 490] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 03/30/2015] [Accepted: 04/06/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND There is growing appreciation for the importance of bacteria in shaping brain development and behaviour. Adolescence and early adulthood are crucial developmental periods during which exposure to harmful environmental factors can have a permanent impact on brain function. Such environmental factors include perturbations of the gut bacteria that may affect gut-brain communication, altering the trajectory of brain development, and increasing vulnerability to psychiatric disorders. Here we assess the effects of gut bacterial depletion from weaning onwards on adult cognitive, social and emotional behaviours and markers of gut-brain axis dysfunction in mice. METHODS Mice were treated with a combination of antibiotics from weaning onwards and effects on behaviours and potential gut-brain axis neuromodulators (tryptophan, monoamines, and neuropeptides) and BDNF expression were assessed in adulthood. RESULTS Antibiotic-treatment depleted and restructured gut microbiota composition of caecal contents and decreased spleen weights in adulthood. Depletion of the gut microbiota from weaning onwards reduced anxiety, induced cognitive deficits, altered dynamics of the tryptophan metabolic pathway, and significantly reduced BDNF, oxytocin and vasopressin expression in the adult brain. CONCLUSIONS Microbiota depletion from weaning onwards by means of chronic treatment with antibiotics in mice impacts on anxiety and cognitive behaviours as well as key neuromodulators of gut-brain communication in a manner that is similar to that reported in germ-free mice. This model may represent a more amenable alternative for germ-free mice in the assessment of microbiota modulation of behaviour. Finally, these data suggest that despite the presence of a normal gut microbiome in early postnatal life, reduced abundance and diversity of the gut microbiota from weaning influences adult behaviours and key neuromodulators of the microbiota-gut-brain axis suggesting that dysregulation of this axis in the post-weaning period may contribute to the pathogenesis of disorders associated with altered anxiety and cognition.
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Affiliation(s)
- Lieve Desbonnet
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
| | - Gerard Clarke
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Psychiatry, University College Cork, Cork, Ireland
| | | | - Orla O'Sullivan
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
| | - Fiona Crispie
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
| | - Rachel D Moloney
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Paul D Cotter
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland
| | - Timothy G Dinan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Psychiatry, University College Cork, Cork, Ireland
| | - John F Cryan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
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Wright EK, Kamm MA, Teo SM, Inouye M, Wagner J, Kirkwood CD. Recent advances in characterizing the gastrointestinal microbiome in Crohn's disease: a systematic review. Inflamm Bowel Dis 2015; 21:1219-28. [PMID: 25844959 PMCID: PMC4450900 DOI: 10.1097/mib.0000000000000382] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 02/03/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND The intestinal microbiota is involved in the pathogenesis of inflammatory bowel disease. A reduction in the diversity of the intestinal microbiota as well as specific taxonomic and functional shifts have been reported in Crohn's disease and may play a central role in the inflammatory process. The aim was to systematically review recent developments in the structural and functional changes observed in the gastrointestinal microbiome in patients with Crohn's Disease. RESULTS Seventy-two abstracts were included in this review. The effects of host genetics, disease phenotype, and inflammatory bowel disease treatment on the gastrointestinal microbiome in Crohn's disease were reviewed, and taxonomic shifts in patients with early and established disease were described. The relative abundance of Bacteroidetes is increased and Firmicutes decreased in Crohn's disease compared with healthy controls. Enterobacteriaceae, specifically Eschericia coli, is enriched in Crohn's disease. Faecalibacterium prausnitzii is found at lower abundance in Crohn's disease and in those with postoperative recurrence. Observed functional changes include major shifts in oxidative stress pathways, a decrease in butanoate and propanoate metabolism gene expression, lower levels of butyrate, and other short-chain fatty acids, decreased carbohydrate metabolism, and decreased amino acid biosynthesis. CONCLUSIONS Changes in microbial composition and function have been described, although a causative role remains to be established. Larger, prospective, and longitudinal studies are required with deep interrogation of the microbiome if causality is to be determined, and refined microbial manipulation is to emerge as a focused therapy.
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Affiliation(s)
- Emily K. Wright
- Department of Gastroenterology, St Vincent's Hospital Melbourne, Australia
- Department of Pathology, University of Melbourne, Australia
| | - Michael A. Kamm
- Department of Gastroenterology, St Vincent's Hospital Melbourne, Australia
- Department of Pathology, University of Melbourne, Australia
- Imperial College, London, United Kingdom; and
| | - Shu Mei Teo
- Department of Pathology, University of Melbourne, Australia
| | - Michael Inouye
- Department of Pathology, University of Melbourne, Australia
| | - Josef Wagner
- Enteric Virus Group, Murdoch Children's Research Institute, Melbourne, Australia
| | - Carl D. Kirkwood
- Enteric Virus Group, Murdoch Children's Research Institute, Melbourne, Australia
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Didari T, Mozaffari S, Nikfar S, Abdollahi M. Effectiveness of probiotics in irritable bowel syndrome: Updated systematic review with meta-analysis. World J Gastroenterol 2015; 21:3072-3084. [PMID: 25780308 PMCID: PMC4356930 DOI: 10.3748/wjg.v21.i10.3072] [Citation(s) in RCA: 210] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/24/2014] [Accepted: 09/30/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the efficacy of probiotics in irritable bowel syndrome (IBS) patients.
METHODS: PubMed, Cochrane library, Scopus, Google Scholar, and Clinicaltrial.gov databases were searched for literature published between September 2007 and December 2013. The applied Mesh terms were “probiotics,”“irritable bowel syndrome,” and “irritable bowel syndrome treatment.” The collected data contained24 clinical trials, of which 15 were eligible for meta-analysis and nine were reviewed systematically. All studies were randomized placebo-controlled trials in patients with IBS that investigated the efficacy of probiotics in IBS improvement. The Jadad score was used to assess the methodological quality of trials. The quality scale ranges from 0 to 5 points, with a score ≤ 2 indicating a low quality report, and a score of ≥ 3 indicating a high quality report. Relative risk (RR), standardized effect size, and 95%CI were calculated using the DerSimonian-Laird method. The Cochran Q test was used to test heterogeneity with P < 0.05. Funnel plots were constructed and Egger’s and Begg-Mazumdar tests were performed to assess publication bias.
RESULTS: A total of 1793 patients were included in the meta-analysis. The RR of responders to therapies based on abdominal pain score in IBS patients for two included trials comparing probiotics to placebo was 1.96 (95%CI: 1.14-3.36; P = 0.01). RR of responders to therapies based on a global symptom score in IBS patients for two included trials comparing probiotics with placebo was 2.43 (95%CI: 1.13-5.21; P = 0.02). For adequate improvement of general symptoms in IBS patients, the RR of seven included trials (six studies) comparing probiotics with placebo was 2.14 (95%CI: 1.08-4.26; P = 0.03). Distension, bloating, and flatulence were evaluated using an IBS severity scoring system in three trials (two studies) to compare the effect of probiotic therapy in IBS patients with placebo, the standardized effect size of mean differences for probiotics therapy was -2.57 (95%CI: -13.05--7.92).
CONCLUSION: Probiotics reduce pain and symptom severity scores. The results demonstrate the beneficial effects of probiotics in IBS patients in comparison with placebo.
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The prevalence of intestinal parasites is not greater among individuals with irritable bowel syndrome: a population-based case-control study. Clin Gastroenterol Hepatol 2015; 13:507-513.e2. [PMID: 25229421 DOI: 10.1016/j.cgh.2014.07.065] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/25/2014] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS The parasites Dientamoeba fragilis and Blastocystis have been detected in feces from patients with irritable bowel syndrome (IBS), therefore these parasites may be involved in IBS pathogenesis. We proposed that a higher prevalence of the parasites in IBS subjects compared with asymptomatic controls would support such a mechanism. We aimed to determine the prevalence of these parasites in IBS subjects (cases) and controls and to identify risk factors associated with parasite carriage. METHODS We performed a population-based, case-control study of an adult population from an internet-based research institute in Denmark. In January 2010, subjects completed a questionnaire based on the Rome III criteria for IBS and answered questions on factors associated with parasite carriage. Respondents (n = 483) were asked to submit fecal samples for parasite testing; samples were analyzed from 124 cases and 204 controls. RESULTS A greater proportion of controls than cases carried the parasites (50% vs 36%; P = .01). D fragilis was detected in a greater proportion of fecal samples from controls than cases (35% vs 23%; P = .03), as was Blastocystis (22% of controls vs 15% of cases; P = .09), and a greater percentage of controls carried more than 1 species of parasite (16% of controls vs 8% of cases; P = .05). D fragilis infection was associated with having children 5 to 18 years old in the household and Blastocystis infection was associated with high income (≥600,000 Danish Kroner/y, approximately $100,000 US dollars/y), no animals in the household, and drinking bottled water. CONCLUSIONS D fragilis and Blastocystis were detected in a greater proportion of fecal samples from the asymptomatic background population in Denmark than from subjects with IBS symptoms. These findings indicate that these parasites are not likely to have a direct role in the pathogenesis of IBS. Longitudinal studies are required to understand their role in gastrointestinal health.
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72
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A randomized clinical trial of Saccharomyces cerevisiae versus placebo in the irritable bowel syndrome. Dig Liver Dis 2015; 47:119-24. [PMID: 25488056 DOI: 10.1016/j.dld.2014.11.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 10/15/2014] [Accepted: 11/04/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND We aimed to evaluate clinical symptoms in subjects with irritable bowel syndrome receiving Saccharomyces cerevisiae in a randomized double-blind placebo-controlled clinical trial. METHODS Overall, 179 adults with irritable bowel syndrome (Rome III criteria) were randomized to receive once daily 500 mg of Saccharomyces cerevisiae, delivered by one capsule (n = 86, F: 84%, age: 42.5 ± 12.5), or placebo (n = 93, F: 88%, age: 45.4 ± 14) for 8 weeks followed by a 3-week washout period. After a 2-week run-in period, cardinal symptoms (abdominal pain/discomfort, bloating/distension, bowel movement difficulty) and changes in stool frequency and consistency were recorded daily and assessed each week. A safety assessment was carried out throughout the study. RESULTS The proportion of responders, defined by an improvement of abdominal pain/discomfort, was significantly higher (p = 0.04) in the treated group than the placebo group (63% vs 47%, OR = 1.88, 95%, CI: 0.99-3.57) in the last 4 weeks of treatment. A non-significant trend of improvement was observed with Saccharomyces cerevisiae for the other symptoms. Saccharomyces cerevisiae was well tolerated and did not affect stool frequency and consistency. CONCLUSION Saccharomyces cerevisiae is well tolerated and reduces abdominal pain/discomfort scores without stool modification. Thus, Saccharomyces cerevisiae may be a new promising candidate for improving abdominal pain in subjects with irritable bowel syndrome.
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Abstract
The aetiology and pathology of IBS, a functional bowel disorder thought to lack an organic cause, is largely unknown. However, studies suggest that various features, such as altered composition of the gut microbiota, together with increased intestinal permeability, a changed balance in the enteroendocrine system and a dysregulated immune system in the gut, most likely have an important role in IBS. Exactly how these entities act together and give rise to symptoms is still unknown, but an altered gut microbiota composition could lead to dysregulation of the intestinal barrier as well as the enteroendocrine and the immune systems, which (through interactions with the nervous system) might generate symptoms. This Review highlights the crosstalk between the gut microbiota, the enteroendocrine system, the immune system and the role of intestinal permeability in patients with IBS.
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74
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Kennedy PJ, Cryan JF, Dinan TG, Clarke G. Irritable bowel syndrome: A microbiome-gut-brain axis disorder? World J Gastroenterol 2014; 20:14105-14125. [PMID: 25339800 PMCID: PMC4202342 DOI: 10.3748/wjg.v20.i39.14105] [Citation(s) in RCA: 201] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/18/2014] [Accepted: 05/26/2014] [Indexed: 02/07/2023] Open
Abstract
Irritable bowel syndrome (IBS) is an extremely prevalent but poorly understood gastrointestinal disorder. Consequently, there are no clear diagnostic markers to help diagnose the disorder and treatment options are limited to management of the symptoms. The concept of a dysregulated gut-brain axis has been adopted as a suitable model for the disorder. The gut microbiome may play an important role in the onset and exacerbation of symptoms in the disorder and has been extensively studied in this context. Although a causal role cannot yet be inferred from the clinical studies which have attempted to characterise the gut microbiota in IBS, they do confirm alterations in both community stability and diversity. Moreover, it has been reliably demonstrated that manipulation of the microbiota can influence the key symptoms, including abdominal pain and bowel habit, and other prominent features of IBS. A variety of strategies have been taken to study these interactions, including probiotics, antibiotics, faecal transplantations and the use of germ-free animals. There are clear mechanisms through which the microbiota can produce these effects, both humoral and neural. Taken together, these findings firmly establish the microbiota as a critical node in the gut-brain axis and one which is amenable to therapeutic interventions.
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75
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Moran C, Shanahan F. Editorial: probiotics and IBS - where are we now? Aliment Pharmacol Ther 2014; 40:318. [PMID: 25040745 DOI: 10.1111/apt.12836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 05/22/2014] [Indexed: 12/17/2022]
Affiliation(s)
- C Moran
- Department of Medicine, Alimentary Pharmabiotic Centre, University College Cork, National University of Ireland, Cork, Ireland
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Abstract
The past decade has witnessed an explosion of knowledge regarding the vast microbial community that resides within our intestine-the gut microbiota. The topic has generated great expectations in terms of gaining a better understanding of disorders ranging from IBD to metabolic disorders and obesity. IBS is a condition for which investigators have long been in search of plausible underlying pathogeneses and it is inevitable that altered composition or function of the gut microbiota will be considered as a potential aetiological factor in at least a subset of patients with IBS. This Review describes the evidence implicating the gut microbiota in not only the expression of the intestinal manifestations of IBS, but also the psychiatric morbidity that coexists in up to 80% of patients with IBS. The evidence described herein ranges from proof-of-concept studies in animals to observational studies and clinical trials in humans. The gut microbiota is subject to influences from a diverse range of factors including diet, antibiotic usage, infection and stress. These factors have previously been implicated in the pathophysiology of IBS and further prompt consideration of a role for the gut microbiota in IBS.
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Ford AC, Moayyedi P, Lacy BE, Lembo AJ, Saito YA, Schiller LR, Soffer EE, Spiegel BMR, Quigley EMM. American College of Gastroenterology monograph on the management of irritable bowel syndrome and chronic idiopathic constipation. Am J Gastroenterol 2014; 109 Suppl 1:S2-26; quiz S27. [PMID: 25091148 DOI: 10.1038/ajg.2014.187] [Citation(s) in RCA: 380] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Alexander C Ford
- 1] Leeds Gastroenterology Institute, St James's University Hospital, Leeds, UK [2] First author on the monograph, but is not a member of the Task Force
| | - Paul Moayyedi
- 1] Farncombe Family Digestive Health Research Institute, Division of Gastroenterology, McMaster University, Hamilton, Ontario, Canada [2] Conducted systematic reviews with the support of A.C. Ford, and carried out the technical analyses of the data independent of the Task Force
| | - Brian E Lacy
- Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, USA
| | - Anthony J Lembo
- Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | | | - Lawrence R Schiller
- Baylor University Medical Center, Digestive Health Associates of Texas, Dallas, Texas, USA
| | - Edy E Soffer
- Division of Gastroenterology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Brennan M R Spiegel
- UCLA School of Medicine, UCLA/VA Center for Outcomes Research and Education (CORE), Los Angeles, California, USA
| | - Eamonn M M Quigley
- Division of Gastroenterology and Hepatology, Houston Methodist Hospital and Weill Cornell Medical College, Houston, Texas, USA
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Hyland NP, Quigley EMM, Brint E. Microbiota-host interactions in irritable bowel syndrome: Epithelial barrier, immune regulation and brain-gut interactions. World J Gastroenterol 2014; 20:8859-8866. [PMID: 25083059 PMCID: PMC4112904 DOI: 10.3748/wjg.v20.i27.8859] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 03/19/2014] [Accepted: 05/14/2014] [Indexed: 02/06/2023] Open
Abstract
Irritable bowel syndrome (IBS) is a common, sometimes debilitating, gastrointestinal disorder worldwide. While altered gut motility and sensation, as well as aberrant brain perception of visceral events, are thought to contribute to the genesis of symptoms in IBS, a search for an underlying aetiology has, to date, proven unsuccessful. Recently, attention has been focused on the microbiota as a possible factor in the pathogenesis of IBS. Prompted by a number of clinical observations, such as the recognition of the de novo development of IBS following enteric infections, as well as descriptions of changes in colonic bacterial populations in IBS and supported by clinical responses to interventions, such as antibiotics and probiotics, that modify the microbiota, various approaches have been taken to investigating the microbiota-host response in IBS, as well as in animal models thereof. From such studies a considerable body of evidence has accumulated to indicate the activation or upregulation of both factors involved in bacterial engagement with the host as well host defence mechanisms against bacteria. Alterations in gut barrier function, occurring in response, or in parallel, to changes in the microbiota, have also been widely described and can be seen to play a pivotal role in generating and sustaining host immune responses both within and beyond the gut. In this manner a plausible hypothesis, based on an altered microbiota and/or an aberrant host response, for the pathogenesis, of at least some instances of IBS, can be generated.
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Pickett-Blakely O. Obesity and irritable bowel syndrome: a comprehensive review. Gastroenterol Hepatol (N Y) 2014; 10:411-416. [PMID: 25904828 PMCID: PMC4302488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Obesity and irritable bowel syndrome (IBS) are prevalent in the United States and cause significant morbidity in those affected. However, it is unclear whether obesity is more prevalent in those affected by IBS or if IBS is more prevalent in obese persons. To evaluate the association between obesity and IBS, a comprehensive review was performed by searching MEDLINE and Embase from 1980 through July 2012. Studies were included if 1 of the outcomes examined the relationship between excess body weight or obesity and IBS. A total of 11 studies (2 pediatric and 9 adult) investigated the relationship between obesity and IBS. The prevalence of obesity in children with IBS ranged from 24.8% to 42%. In adults, the prevalence of IBS in obese subjects varied from 11.6% to 24%, depending on the study population. Two studies did not show increased odds of IBS in obese patients; however, 2 studies showed that symptoms were more severe in obese patients affected by IBS, while 1 of these studies demonstrated that IBS symptom severity improved after bariatric surgery. The findings of this comprehensive review of the literature suggest that the frequency of IBS in obese children and adults is variable and depends on the study population. Due to the heterogeneity in study populations, outcome assessment, and methodology in the existing literature, further studies are needed to determine whether obesity is associated with IBS.
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Affiliation(s)
- Octavia Pickett-Blakely
- Dr Pickett-Blakely is the director of the Small Bowel Disorders and Nutrition Program in the Division of Gastroenterology of the University of Pennsylvania Perelman School of Medicine in Philadelphia, Pennsylvania
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Muscatello MRA, Bruno A, Scimeca G, Pandolfo G, Zoccali RA. Role of negative affects in pathophysiology and clinical expression of irritable bowel syndrome. World J Gastroenterol 2014; 20:7570-7586. [PMID: 24976697 PMCID: PMC4069288 DOI: 10.3748/wjg.v20.i24.7570] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 01/18/2014] [Accepted: 04/03/2014] [Indexed: 02/06/2023] Open
Abstract
Irritable bowel syndrome (IBS) is regarded as a multifactorial disease in which alterations in the brain-gut axis signaling play a major role. The biopsychosocial model applied to the understanding of IBS pathophysiology assumes that psychosocial factors, interacting with peripheral/central neuroendocrine and immune changes, may induce symptoms of IBS, modulate symptom severity, influence illness experience and quality of life, and affect outcome. The present review focuses on the role of negative affects, including depression, anxiety, and anger, on pathogenesis and clinical expression of IBS. The potential role of the autonomic nervous system, stress-hormone system, and immune system in the pathophysiology of both negative affects and IBS are taken into account. Psychiatric comorbidity and subclinical variations in levels of depression, anxiety, and anger are further discussed in relation to the main pathophysiological and symptomatic correlates of IBS, such as sensorimotor functions, gut microbiota, inflammation/immunity, and symptom reporting.
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Abstract
PURPOSE This article provides an update and overview of a nursing research program focused on understanding the pathophysiology and management of irritable bowel syndrome (IBS). METHODS This review includes English language papers from the United States, Europe, and Asia (e.g., South Korea) from 1999 to 2013. We addressed IBS as a health problem, emerging etiologies, diagnostic and treatment approaches and the importance of a biopsychosocial model. RESULTS IBS is a chronic, functional gastrointestinal disorder characterized by recurrent episodes of abdominal pain and alterations in bowel habit (diarrhea, constipation, mixed). It is a condition for which adults, particularly women ages 20-45, seek health care services in both the United States and South Korea. Clinically, nurses play key roles in symptom prevention and management including designing and implementing approaches to enhance the patients' self-management strategies. Multiple mechanisms are believed to participate in the development and maintenance of IBS symptoms including autonomic nervous system dysregulation, intestinal inflammation, intestinal dysbiosis, dietary intolerances, alterations in emotion regulation, heightened visceral pain sensitivity, hypothalamic-pituitary-adrenal dysregulation, and dysmotility. Because IBS tends to occur in families, genetic factors may also contribute to the pathophysiology. Patients with IBS often report a number of co-morbid disorders and/or symptoms including poor sleep. CONCLUSION The key to planning effective management strategies is to understand the heterogeneity of this disorder. Interventions for IBS include non-pharmacological strategies such as cognitive behavior therapy, relaxation strategies, and exclusion diets.
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Affiliation(s)
- Margaret Heitkemper
- Department of Biobehavioral Nursing & Health Systems, University of Washington, Seattle, USA.
| | - Monica Jarrett
- Department of Biobehavioral Nursing & Health Systems, University of Washington, Seattle, USA
| | - Sang-Eun Jun
- College of Nursing, Keimyung University, Daegu, Korea
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Parsons K, Goepp J, Dechairo B, Fowler E, Markward N, Hanaway P, McBride T, Landis D. Novel Testing Enhances Irritable Bowel Syndrome Medical Management: The IMMINENT Study. Glob Adv Health Med 2014; 3:25-32. [PMID: 24891991 PMCID: PMC4030615 DOI: 10.7453/gahmj.2013.100] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Primary Study Objective: To evaluate the economic utility of a fecal biomarker panel structured to suggest alternative, treatable diagnoses in patients with symptoms of irritable bowel syndrome (IBS) by quantifying, comparing, and contrasting health service costs between tested and non-tested patients. Study Design: Retrospective, matched cohort study comparing direct medical costs for IBS patients undergoing fecal biomarker testing with those of matched control subjects. Methods: We examined de-identified medical and pharmacy claims of a large American pharmacy benefit manager to identify plan members who underwent panel testing, were eligible for covered benefits for at least 180 days prior to the test date, and had data available for 30, 90, and 365 days after that date. We used propensity score matching to develop population-based control cohorts for each tested cohort, comprised of records with IBS-related diagnoses but for which panel testing was not performed. Primary outcome measures were diagnostic and medical services costs as determined from claims data. Results: Two hundred nine records from tested subjects met inclusion criteria. The only significant baseline differences between groups were laboratory costs, which were significantly higher in each tested cohort. At each follow-up time point, total medical and gastrointestinal procedural costs were significantly higher in non-tested cohorts. Within tested cohorts, costs declined significantly from baseline, while costs rose significantly in non-tested control cohorts; these differences were also significant between groups at each time point. Conclusions: Structured fecal biomarker panel testing was associated with significantly lower medical and gastrointestinal procedural costs in this study of patients with IBS symptoms.
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Affiliation(s)
- Kelly Parsons
- Express Scripts, St Louis, Missouri (Dr Parsons), United States
| | - Julius Goepp
- Lupine Creative Consulting (Dr Goepp), United States
| | - Bryan Dechairo
- Express Scripts, St Louis, Missouri (Dr Dechairo), United States
| | - Elizabeth Fowler
- Genova Diagnostics, Asheville, North Carolina (Dr Fowler), United States
| | - Nathan Markward
- Express Scripts, St Louis, Missouri (Dr Markward), United States
| | - Patrick Hanaway
- Institute for Functional Medicine, Federal Way, Washington (Dr Hanaway), United States
| | - Teresa McBride
- Genova Diagnostics, Asheville, North Carolina (Dr McBride), United States
| | - Darryl Landis
- Genova Diagnostics, Asheville, North Carolina (Dr Landis), United States
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Shanahan F, Quigley EMM. Manipulation of the microbiota for treatment of IBS and IBD-challenges and controversies. Gastroenterology 2014; 146:1554-63. [PMID: 24486051 DOI: 10.1053/j.gastro.2014.01.050] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 01/11/2014] [Accepted: 01/23/2014] [Indexed: 02/06/2023]
Abstract
There is compelling rationale for manipulating the microbiota to treat inflammatory bowel diseases (IBDs). Although studies of animal models of intestinal inflammation produced promising results, trials in humans have been disappointing. In contrast to IBD, the role of the microbiota in the development of irritable bowel syndrome (IBS) only recently has been considered, but early stage results have been encouraging. As pharmaceutical companies develop fewer truly novel agents for treatment of these disorders, consumers seek safer, long-term strategies to deal with chronic symptoms. We assess the rationale for modulating the microbiota for treatment of IBD and IBS, and discuss whether current concepts are simplistic and overstated or simply under-researched. Are claims exaggerated and expectations unrealistic? Difficulties with microbiota terminology and technologies, as well as differences among patients and the heterogeneity of these diseases, pose additional challenges in developing microbiota-based therapies for IBD and IBS.
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Affiliation(s)
- Fergus Shanahan
- Alimentary Pharmabiotic Centre, University College Cork, National University of Ireland, Cork, Ireland; Department of Medicine, University College Cork, National University of Ireland, Cork, Ireland.
| | - Eamonn M M Quigley
- Alimentary Pharmabiotic Centre, University College Cork, National University of Ireland, Cork, Ireland; Division of Gastroenterology and Hepatology, Houston Methodist, Houston, Texas
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84
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Abstract
Gut microbiota alterations are increasingly being recognized as an important factor in the pathogenesis and pathophysiology of Irritable bowel syndrome (IBS). The onset of IBS symptoms after a bout of gastroenteritis comprises one of the strongest indications for the importance of gut microbiota for IBS. Moreover, recent studies have identified several susceptibility genes for IBS involved in the innate immunity and recognition of bacteria but also maintaining the integrity of the intestinal barrier. During recent years, it has also been demonstrated that IBS patients, or subgroups thereof, may have an altered microbiota composition relative to healthy individuals, mainly based on the analysis of fecal microbiota. Moreover, a positive effect of treatment with non-absorbable antibiotics and probiotics in IBS provides further indirect support for the relevance of gut microbiota alterations in IBS.
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Affiliation(s)
- Lena Ohman
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
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85
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Quigley EMM. Gut bacteria in health and disease. Gastroenterol Hepatol (N Y) 2013; 9:560-569. [PMID: 24729765 PMCID: PMC3983973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A new era in medical science has dawned with the realization of the critical role of the "forgotten organ," the gut micro-biota, in health and disease. Central to this beneficial interaction between the microbiota and host is the manner in which bacteria and most likely other microorganisms contained within the gut communicate with the host's immune system and participate in a variety of metabolic processes of mutual benefit to the host and the microbe. The advent of high-throughput methodologies and the elaboration of sophisticated analytic systems have facilitated the detailed description of the composition of the microbial constituents of the human gut, as never before, and are now enabling comparisons to be made between health and various disease states. Although the latter approach is still in its infancy, some important insights have already been gained about how the microbiota might influence a number of disease processes both within and distant from the gut. These discoveries also lay the groundwork for the development of therapeutic strategies that might modify the microbiota (eg, through the use of probiot-ics). Although this area holds much promise, more high-quality trials of probiotics, prebiotics, and other microbiota-modifying approaches in digestive disorders are needed, as well as laboratory investigations of their mechanisms of action.
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Affiliation(s)
- Eamonn M M Quigley
- Dr Quigley is chief of the Division of Gastroenterology and Hepatology at Houston Methodist Hospital in Houston, Texas
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86
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Park AJ, Collins J, Blennerhassett PA, Ghia JE, Verdu EF, Bercik P, Collins SM. Altered colonic function and microbiota profile in a mouse model of chronic depression. Neurogastroenterol Motil 2013; 25:733-e575. [PMID: 23773726 PMCID: PMC3912902 DOI: 10.1111/nmo.12153] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 04/13/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND Depression often coexists with the irritable bowel syndrome (IBS) which is characterized by alterations in gut function. There is emerging evidence that the microbial composition (microbiota) of the gut is altered in IBS, but the basis for this is poorly understood. The aim of this study was to determine whether the induction of chronic depression results in changes in the colonic function and in its microbial community, and to explore underlying mechanisms. METHODS Bilateral olfactory bulbectomy (OBx) was used to induce depression-like behavior in mice. Colonic function was assessed by measuring muscle contractility, pellet excretion, c-fos activity, and serotonin levels. Microbiota profiles were obtained using denaturing gradient gel electrophoresis (DGGE). The hypothalamic-pituitary axis (HPA) was assessed by the hypothalamic expression of corticotropin-releasing hormone (CRH). In separate studies, mice without OBx received CRH via intracerebroventricular (ICV) infusion for 4 weeks prior to assessing colonic function and microbiota profiles. KEY RESULTS Olfactory bulbectomy mice demonstrated chronic depression- and anxiety-like behaviors associated with elevated central CRH expression and increases in c-Fos activity, serotonin levels, and motility in the colon. These changes were accompanied by an altered intestinal microbial profile. Central CRH administration produced similar changes in behavior and motility and altered the microbiota profile in the colon. CONCLUSIONS & INFERENCES The induction of chronic depression alters motor activity and the microbial profile in the colon likely via activation of the HPA. These findings provide a basis for linking the behavioral and gastrointestinal manifestations of IBS.
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Affiliation(s)
- A J Park
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster UniversityHamilton, Canada
| | - J Collins
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster UniversityHamilton, Canada
| | - P A Blennerhassett
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster UniversityHamilton, Canada
| | - J E Ghia
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster UniversityHamilton, Canada
| | - E F Verdu
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster UniversityHamilton, Canada
| | - P Bercik
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster UniversityHamilton, Canada
| | - S M Collins
- Address for Correspondence, Stephen Collins, MBBS, FRCPC, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, HSC 2E16, Hamilton, ON, Canada L8N 3Z5., Tel: 905-525-9140 #22184; fax: 905 524 1346;, e-mail:
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87
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Guinane CM, Cotter PD. Role of the gut microbiota in health and chronic gastrointestinal disease: understanding a hidden metabolic organ. Therap Adv Gastroenterol 2013; 6:295-308. [PMID: 23814609 PMCID: PMC3667473 DOI: 10.1177/1756283x13482996] [Citation(s) in RCA: 477] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The human gut microbiota has become the subject of extensive research in recent years and our knowledge of the resident species and their potential functional capacity is rapidly growing. Our gut harbours a complex community of over 100 trillion microbial cells which influence human physiology, metabolism, nutrition and immune function while disruption to the gut microbiota has been linked with gastrointestinal conditions such as inflammatory bowel disease and obesity. Here, we review the many significant recent studies that have centred on further enhancing our understanding of the complexity of intestinal communities as well as their genetic and metabolic potential. These have provided important information with respect to what constitutes a 'healthy gut microbiota' while furthering our understanding of the role of gut microbes in intestinal diseases. We also highlight recently developed genomic and other tools that are used to study the gut microbiome and, finally, we consider the manipulation of the gut microbiota as a potential therapeutic option to treat chronic gastrointestinal disease.
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Affiliation(s)
| | - Paul D. Cotter
- Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland The Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
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88
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Sanders ME, Guarner F, Guerrant R, Holt PR, Quigley EMM, Sartor RB, Sherman PM, Mayer EA. An update on the use and investigation of probiotics in health and disease. Gut 2013; 62:787-96. [PMID: 23474420 PMCID: PMC4351195 DOI: 10.1136/gutjnl-2012-302504] [Citation(s) in RCA: 315] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Probiotics are derived from traditional fermented foods, from beneficial commensals or from the environment. They act through diverse mechanisms affecting the composition or function of the commensal microbiota and by altering host epithelial and immunological responses. Certain probiotic interventions have shown promise in selected clinical conditions where aberrant microbiota have been reported, such as atopic dermatitis, necrotising enterocolitis, pouchitis and possibly irritable bowel syndrome. However, no studies have been conducted that can causally link clinical improvements to probiotic-induced microbiota changes. Whether a disease-prone microbiota pattern can be remodelled to a more robust, resilient and disease-free state by probiotic administration remains a key unanswered question. Progress in this area will be facilitated by: optimising strain, dose and product formulations, including protective commensal species; matching these formulations with selectively responsive subpopulations; and identifying ways to manipulate diet to modify bacterial profiles and metabolism.
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Affiliation(s)
| | - Francisco Guarner
- Digestive System Research Unit, University Hospital Vall d’Hebron, CIBEREHD, Barcelona, Spain
| | - Richard Guerrant
- Center for Global Health, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Peter R Holt
- Laboratory of Biochemical Genetics & Metabolism, The Rockefeller University, New York City, New York, USA
| | - Eamonn MM Quigley
- Department of Medicine, Alimentary Pharmabiotic Centre, University College Cork, Ireland,Division of Gastroenterology and Hepatology, The Methodist Hospital and Weill Cornell School of Medicine, Houston, Texas, USA
| | - R Balfour Sartor
- Departments of Medicine, Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, USA
| | - Philip M Sherman
- The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Emeran A Mayer
- Division of Digestive Diseases, University of California, Los Angeles, California, USA
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89
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Jeffery IB, O’Toole PW. Diet-microbiota interactions and their implications for healthy living. Nutrients 2013; 5:234-52. [PMID: 23344252 PMCID: PMC3571646 DOI: 10.3390/nu5010234] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 01/10/2013] [Accepted: 01/10/2013] [Indexed: 02/06/2023] Open
Abstract
It is well established that diet influences the health of an individual and that a diet rich in plant-based foods has many advantages in relation to the health and well-being of an individual. What has been unclear until recently is the large contribution of the gut microbiota to this effect. As well as providing basic nutritional requirements, the long-term diet of an animal modifies its gut microbiota. In adults, diets that have a high proportion of fruit and vegetables and a low consumption of meat are associated with a highly diverse microbiota and are defined by a greater abundance of Prevotella compared to Bacteroides, while the reverse is associated with a diet that contains a low proportion of plant-based foods. Furthermore, it is becoming increasingly clear that the effect of the microbial ecology of the gut goes beyond the local gut immune system and is implicated in immune-related disorders, such as IBS, diabetes and inflamm-ageing. In this review, we investigate the evidence that a balanced diet leads to a balanced, diverse microbiota with significant consequences for healthy ageing by focusing on conditions of interest.
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Affiliation(s)
- Ian B. Jeffery
- Department of Microbiology, University College Cork, College Road, Cork, Ireland; E-Mail:
- Alimentary Pharmabiotic Centre, University College Cork, College Road, Cork, Ireland
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +353-(0)21-490-1306; Fax: +353-(0)21-490-3997
| | - Paul W. O’Toole
- Department of Microbiology, University College Cork, College Road, Cork, Ireland; E-Mail:
- Alimentary Pharmabiotic Centre, University College Cork, College Road, Cork, Ireland
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90
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Quigley EMM. Bugs on the brain; brain in the gut--seeking explanations for common gastrointestinal symptoms. Ir J Med Sci 2012. [PMID: 23179664 DOI: 10.1007/s11845-012-0865-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Gastrointestinal symptoms such as heartburn, indigestion (or dyspepsia), bloating, distension, constipation, abdominal pain, abdominal discomfort and diarrhoea are extremely common worldwide. For some, such symptoms can prove to be chronic and disabling. METHODS The recent literature on irritable bowel syndrome and, in particular, work emanating form this authors research group, was reviewed. RESULTS These functional symptoms commonly occur in aggregations, referred to as functional gastrointestinal disorders (FGIDs). Some of the FGIDs and, most notably irritable bowel syndrome (IBS), have achieved a degree of scientific and clinical credibility as coherent entities. Several lines of evidence ranging from gut motility to the microbiota are under investigation in attempts to explain IBS or its symptomatology. CONCLUSION Though biomarkers for IBS and other FGIDs have proven elusive, considerable progress has been made in understanding possible aetiological factors in IBS; progress which may well lead to better therapeutic strategies.
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Affiliation(s)
- E M M Quigley
- Department of Medicine, Alimentary Pharmbiotic Centre, University College Cork, Cork University Hospital, Clinical Sciences Building, Cork, Ireland.
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