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Peddinti V, Avaghade MM, Suthar SU, Rout B, Gomte SS, Agnihotri TG, Jain A. Gut instincts: Unveiling the connection between gut microbiota and Alzheimer's disease. Clin Nutr ESPEN 2024; 60:266-280. [PMID: 38479921 DOI: 10.1016/j.clnesp.2024.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 02/16/2024] [Indexed: 04/13/2024]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder marked by neuroinflammation and gradual cognitive decline. Recent research has revealed that the gut microbiota (GM) plays an important role in the pathogenesis of AD through the microbiota-gut-brain axis. However, the mechanism by which GM and microbial metabolites alter brain function is not clearly understood. GM dysbiosis increases the permeability of the intestine, alters the blood-brain barrier permeability, and elevates proinflammatory mediators causing neurodegeneration. This review article introduced us to the composition and functions of GM along with its repercussions of dysbiosis in relation to AD. We also discussed the importance of the gut-brain axis and its role in communication. Later we focused on the mechanism behind gut dysbiosis and the progression of AD including neuroinflammation, oxidative stress, and changes in neurotransmitter levels. Furthermore, we highlighted recent developments in AD management, such as microbiota-based therapy, dietary interventions like prebiotics, probiotics, and fecal microbiota transplantation. Finally, we concluded with challenges and future directions in AD research based on GM.
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Affiliation(s)
- Vasu Peddinti
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Palaj, Gandhinagar, 382355, Gujarat, India
| | - Manoj Mohan Avaghade
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Palaj, Gandhinagar, 382355, Gujarat, India
| | - Sunil Umedmal Suthar
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Palaj, Gandhinagar, 382355, Gujarat, India
| | - Biswajit Rout
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Palaj, Gandhinagar, 382355, Gujarat, India
| | - Shyam Sudhakar Gomte
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Palaj, Gandhinagar, 382355, Gujarat, India
| | - Tejas Girish Agnihotri
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Palaj, Gandhinagar, 382355, Gujarat, India
| | - Aakanchha Jain
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad, Palaj, Gandhinagar, 382355, Gujarat, India.
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2
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Yang K, Zhang Z, Zhang Q, Zhang H, Liu X, Jia Z, Ying Z, Liu W. Potential diagnostic markers and therapeutic targets for periodontitis and Alzheimer's disease based on bioinformatics analysis. J Periodontal Res 2024; 59:366-380. [PMID: 38189472 DOI: 10.1111/jre.13220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 11/02/2023] [Accepted: 11/22/2023] [Indexed: 01/09/2024]
Abstract
BACKGROUND AND OBJECTIVE As a chronic inflammatory disease, periodontitis threatens oral health and is a risk factor for Alzheimer's disease (AD). There is growing evidence that these two diseases are closely related. However, current research is still incomplete in understanding the common genes and common mechanisms between periodontitis and AD. In this study, we aimed to identify common genes in periodontitis and AD and analyze the relationship between crucial genes and immune cells to provide new therapeutic targets for clinical treatment. MATERIALS AND METHODS We evaluated differentially expressed genes (DEGs) specific to periodontitis and AD. Co-expressed genes were identified by obtaining gene expression profile data from the Gene Expression Omnibus (GEO) database. Using the STRING database, protein-protein interaction (PPI) networks were constructed, and essential genes were identified. We also used four algorithms to identify critical genes and constructed regulatory networks. The association of crucial genes with immune cells and potential therapeutic effects was also assessed. RESULTS PDGFRB, VCAN, TIMP1, CHL1, EFEMP2, and IGFBP5 were obtained as crucial common genes. Immune infiltration analysis showed that Natural killer cells and Myeloid-derived suppressor cells were significantly differentially expressed in patients with PD and AD compared with the normal group. FOXC1 and GATA2 are important TFs for PD and AD. MiR-23a, miR-23b, miR-23a, and miR-23b were associated with AD and PD. Finally, the hub genes retrieved from the DSigDB database indicate multiple drug molecule and drug-target interactions. CONCLUSION This study reveals commonalities in common hub genes and immune infiltration between periodontitis and AD, and the analysis of six hub genes and immune cells may provide new insights into potential therapeutic directions for the pathogenesis of periodontitis complicated by AD.
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Affiliation(s)
- Kai Yang
- Acupuncture and Moxibustion Massage College, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Zhaoqi Zhang
- The First Clinical Medical College of Shandong University of Chinese Medicine, Jinan, China
| | - Qingyuan Zhang
- The First Clinical Medical College of Shandong University of Chinese Medicine, Jinan, China
| | - Hongyu Zhang
- Rehabilitation Department, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xiaoju Liu
- The First Clinical Medical College of Shandong University of Chinese Medicine, Jinan, China
| | - Zhicheng Jia
- The First Clinical Medical College of Shandong University of Chinese Medicine, Jinan, China
| | - Zhenhao Ying
- Rehabilitation Department, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Wei Liu
- Department of Neurology, The Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
- Shandong University of Traditional Chinese Medicine, Jinan, China
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Hofford RS, Kiraly DD. Clinical and Preclinical Evidence for Gut Microbiome Mechanisms in Substance Use Disorders. Biol Psychiatry 2024; 95:329-338. [PMID: 37573004 PMCID: PMC10884738 DOI: 10.1016/j.biopsych.2023.08.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/14/2023]
Abstract
Substance use disorders are a set of recalcitrant neuropsychiatric conditions that cause tremendous morbidity and mortality and are among the leading causes of loss of disability-adjusted life years worldwide. While each specific substance use disorder is driven by problematic use of a different substance, they all share a similar pattern of escalating and out-of-control substance use, continued use despite negative consequences, and a remitting/relapsing pattern over time. Despite significant advances in our understanding of the neurobiology of these conditions, current treatment options remain few and are ineffective for too many individuals. In recent years, there has been a rapidly growing body of literature demonstrating that the resident population of microbes in the gastrointestinal tract, collectively called the gut microbiome, plays an important role in modulating brain and behavior in preclinical and clinical studies of psychiatric disease. While these findings have not yet been translated into clinical practice, this remains an important and exciting avenue for translational research. In this review, we highlight the current state of microbiome-brain research within the substance use field with a focus on both clinical and preclinical studies. We also discuss potential neurobiological mechanisms underlying microbiome effects on models of substance use disorder and propose future directions to bring these findings from bench to bedside.
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Affiliation(s)
- Rebecca S Hofford
- Department of Physiology & Pharmacology, Wake Forest University School of Medicine, Atrium Health Wake Forest Baptist, Winston-Salem, North Carolina
| | - Drew D Kiraly
- Department of Physiology & Pharmacology, Wake Forest University School of Medicine, Atrium Health Wake Forest Baptist, Winston-Salem, North Carolina; Department of Psychiatry, Wake Forest University School of Medicine, Atrium Health Wake Forest Baptist, Winston-Salem, North Carolina.
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4
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Ragavan ML, Hemalatha S. The functional roles of short chain fatty acids as postbiotics in human gut: future perspectives. Food Sci Biotechnol 2024; 33:275-285. [PMID: 38222911 PMCID: PMC10786766 DOI: 10.1007/s10068-023-01414-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/26/2023] [Accepted: 08/07/2023] [Indexed: 01/16/2024] Open
Abstract
The significance of gut microbiome and their metabolites (postbiotics) on human health could be a promising approach to treat various diseases that includes inflammatory bowel diseases, colon cancer, and many neurological disorders. Probiotics with potential mental health benefits (psychobiotics) can alter the gut-brain axis via immunological, humoral, neuronal, and metabolic pathways. Recently, probiotic bacteria like Lactobacillus and Bifidobacterium have been demonstrated for SCFAs production, which play a crucial role in a variety of diseases. These acids could enhance the production of mucins, antimicrobial proteins (bacteriocins and peptides), cytokines (Interleukin 10 and 18) and neurotransmitters (serotonin) in the intestine to main the gut microbiota, intestinal barrier system and other immune functions. In this review, we discuss about two mechanisms such as (i) SCFAs mediated intestinal barrier system, and (ii) SCFAs mediated gut-brain axis to elucidate the therapeutic options for the treatment/prevention of various diseases.
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Affiliation(s)
| | - S. Hemalatha
- School of Life Sciences, BSACIST, Vandalur, Chennai, Tamil Nadu India
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Simão DO, Vieira VS, Tosatti JAG, Gomes KB. Lipids, Gut Microbiota, and the Complex Relationship with Alzheimer's Disease: A Narrative Review. Nutrients 2023; 15:4661. [PMID: 37960314 PMCID: PMC10649859 DOI: 10.3390/nu15214661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/28/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023] Open
Abstract
Alzheimer's Disease (AD) is a multifactorial, progressive, and chronic neurodegenerative disorder associated with the aging process. Memory deficits, cognitive impairment, and motor dysfunction are characteristics of AD. It is estimated that, by 2050, 131.5 million people will have AD. There is evidence that the gastrointestinal microbiome and diet may contribute to the development of AD or act preventively. Communication between the brain and the intestine occurs through immune cells in the mucosa and endocrine cells, or via the vagus nerve. Aging promotes intestinal dysbiosis, characterized by an increase in pro-inflammatory pathogenic bacteria and a reduction in anti-inflammatory response-mediating bacteria, thus contributing to neuroinflammation and neuronal damage, ultimately leading to cognitive decline. Therefore, the microbiota-gut-brain axis has a significant impact on neurodegenerative disorders. Lipids may play a preventive or contributory role in the development of AD. High consumption of saturated and trans fats can increase cortisol release and lead to other chronic diseases associated with AD. Conversely, low levels of omega-3 polyunsaturated fatty acids may be linked to neurodegenerative diseases. Unlike other studies, this review aims to describe, in an integrative way, the interaction between the gastrointestinal microbiome, lipids, and AD, providing valuable insights into how the relationship between these factors affects disease progression, contributing to prevention and treatment strategies.
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Affiliation(s)
- Daiane Oliveira Simão
- Faculty of Medicine, Federal University of Minas Gerais, Professor Alfredo Balena Avenue, 190, Santa Efigênia, Belo Horizonte 30130-100, MG, Brazil;
| | - Vitoria Silva Vieira
- Department of Nutrition, School of Nursing, Federal University of Minas Gerais, Professor Alfredo Balena Avenue, 190, Santa Efigênia, Belo Horizonte 30130-100, MG, Brazil;
| | - Jéssica Abdo Gonçalves Tosatti
- Department of Clinical and Toxicological Analyzes, Faculty of Pharmacy, Federal University of Minas Gerais, Presidente Antônio Carlos Avenue, 6627, Pampulha, Belo Horizonte 31270-901, MG, Brazil;
| | - Karina Braga Gomes
- Faculty of Medicine, Federal University of Minas Gerais, Professor Alfredo Balena Avenue, 190, Santa Efigênia, Belo Horizonte 30130-100, MG, Brazil;
- Department of Clinical and Toxicological Analyzes, Faculty of Pharmacy, Federal University of Minas Gerais, Presidente Antônio Carlos Avenue, 6627, Pampulha, Belo Horizonte 31270-901, MG, Brazil;
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Thakkar A, Vora A, Kaur G, Akhtar J. Dysbiosis and Alzheimer's disease: role of probiotics, prebiotics and synbiotics. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:2911-2923. [PMID: 37284896 DOI: 10.1007/s00210-023-02554-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 05/26/2023] [Indexed: 06/08/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease characterized by dementia and the accumulation of amyloid beta in the brain. Recently, microbial dysbiosis has been identified as one of the major factors involved in the onset and progression of AD. Imbalance in gut microbiota is known to affect central nervous system (CNS) functions through the gut-brain axis and involves inflammatory, immune, neuroendocrine and metabolic pathways. An altered gut microbiome is known to affect the gut and BBB permeability, resulting in imbalance in levels of neurotransmitters and neuroactive peptides/factors. Restoration of levels of beneficial microorganisms in the gut has demonstrated promising effects in AD in pre-clinical and clinical studies. The current review enlists the important beneficial microbial species present in the gut, the effect of their metabolites on CNS, mechanisms involved in dysbiosis related to AD and the beneficial effects of probiotics on AD. It also highlights challenges involved in large-scale manufacturing and quality control of probiotic formulations.
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Affiliation(s)
- Ami Thakkar
- Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, Shri Vile Parle Kelavani Mandal's Narsee Monjee Institute of Management Studies, Mumbai, India
| | - Amisha Vora
- Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, Shri Vile Parle Kelavani Mandal's Narsee Monjee Institute of Management Studies, Mumbai, India.
| | - Ginpreet Kaur
- Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, Shri Vile Parle Kelavani Mandal's Narsee Monjee Institute of Management Studies, Mumbai, India
| | - Jamal Akhtar
- Central Council for Research in Unani Medicine, Ministry of AYUSH, New Delhi, India
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Ullah H, Arbab S, Tian Y, Liu CQ, Chen Y, Qijie L, Khan MIU, Hassan IU, Li K. The gut microbiota-brain axis in neurological disorder. Front Neurosci 2023; 17:1225875. [PMID: 37600019 PMCID: PMC10436500 DOI: 10.3389/fnins.2023.1225875] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 07/07/2023] [Indexed: 08/22/2023] Open
Abstract
The gut microbiota (GM) plays an important role in the physiology and pathology of the host. Microbiota communicate with different organs of the organism by synthesizing hormones and regulating body activity. The interaction of the central nervous system (CNS) and gut signaling pathways includes chemical, neural immune and endocrine routes. Alteration or dysbiosis in the gut microbiota leads to different gastrointestinal tract disorders that ultimately impact host physiology because of the abnormal microbial metabolites that stimulate and trigger different physiologic reactions in the host body. Intestinal dysbiosis leads to a change in the bidirectional relationship between the CNS and GM, which is linked to the pathogenesis of neurodevelopmental and neurological disorders. Increasing preclinical and clinical studies/evidence indicate that gut microbes are a possible susceptibility factor for the progression of neurological disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS) and autism spectrum disorder (ASD). In this review, we discuss the crucial connection between the gut microbiota and the central nervous system, the signaling pathways of multiple biological systems and the contribution of gut microbiota-related neurological disorders.
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Affiliation(s)
- Hanif Ullah
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Safia Arbab
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Yali Tian
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Chang-qing Liu
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Yuwen Chen
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Li Qijie
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Muhammad Inayat Ullah Khan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Inam Ul Hassan
- Department of Microbiology, Hazara University Mansehra, Mansehra, Pakistan
| | - Ka Li
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
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8
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Guo X, Zhang X, Tang P, Chong L, Li R. Integration of genome-wide association studies (GWAS) and microbiome data highlights the impact of sulfate-reducing bacteria on Alzheimer's disease. Age Ageing 2023; 52:afad112. [PMID: 37466641 DOI: 10.1093/ageing/afad112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND observational studies have indicated that gut microbiome dysbiosis was associated with Alzheimer's disease (ad). However, the results are largely inconsistent and it remains unknown whether the association is causal in nature. METHODS leveraging observational studies and genome-wide association studies (GWAS) on the gut microbiome in ad patients, we pooled the microbiome data (N = 1,109) to screen the microbiota significantly altered in ad patients and then conducted Mendelian randomisation (MR) study to determine the causal associations between altered microbiota (N = 18,340) and ad using two different ad GWAS datasets (N = 63,926 and N = 472,868) using the inverse variance-weighted (IVW) method. RESULTS the combined effect sizes from observational studies showed that 8 phyla, 18 classes, 22 orders, 37 families, 78 genera and 109 species significantly changed in ad patients. Using the MR analysis, we found that two classes, one order, one family and one genus were suggestively associated with ad consistently in two different GWAS datasets. Both observational studies and MR analysis simultaneously showed that Desulfovibrionales (order) and Desulfovibrionaceae (family), which were mainly implicated in dissimilatory sulfate reduction, were significantly associated with an elevated risk of ad. CONCLUSIONS our findings demonstrated that the abundance of sulfate-reducing bacteria was increased in ad patients, which was causally linked to an increased risk of ad. Further efforts are warranted to clarify the underlying mechanisms, which will provide new insight into the prevention and treatment of ad.
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Affiliation(s)
- Xingzhi Guo
- Department of Geriatric Neurology, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, People's Republic of China
- Shaanxi Provincial Clinical Research Center for Geriatric Medicine, Xi'an Shaanxi 710068, People's Republic of China
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an Shaanxi 710072, People's Republic of China
| | - Xin Zhang
- Department of Geriatric Neurology, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, People's Republic of China
- Shaanxi Provincial Clinical Research Center for Geriatric Medicine, Xi'an Shaanxi 710068, People's Republic of China
| | - Peng Tang
- Department of Geriatric Neurology, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, People's Republic of China
- Shaanxi Provincial Clinical Research Center for Geriatric Medicine, Xi'an Shaanxi 710068, People's Republic of China
| | - Li Chong
- Department of Geriatric Neurology, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, People's Republic of China
- Shaanxi Provincial Clinical Research Center for Geriatric Medicine, Xi'an Shaanxi 710068, People's Republic of China
| | - Rui Li
- Department of Geriatric Neurology, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, People's Republic of China
- Shaanxi Provincial Clinical Research Center for Geriatric Medicine, Xi'an Shaanxi 710068, People's Republic of China
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an Shaanxi 710072, People's Republic of China
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Hung CC, Crowe-White KM, McDonough IM. A seed and soil model of gut dysbiosis in Alzheimer's disease. Aging (Albany NY) 2023; 15:5235-5237. [PMID: 37338514 PMCID: PMC10333083 DOI: 10.18632/aging.204840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/17/2023] [Indexed: 06/21/2023]
Affiliation(s)
- Chun-Che Hung
- Department of Occupational Therapy and Graduate Institute of Behavioral Sciences, Chang Gung University, Taiwan
| | - Kristi M. Crowe-White
- Department of Human Nutrition and Hospitality Management, The University of Alabama, Tuscaloosa, AL 35487, USA
- Alabama Research Institute on Aging, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Ian M. McDonough
- Alabama Research Institute on Aging, The University of Alabama, Tuscaloosa, AL 35487, USA
- Department of Psychology, The University of Alabama, Tuscaloosa, AL 35487, USA
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Yang J, Li J, Zhang X, Zhou Q, Wang J, Chen Q, Meng X, Xia Y. Effects of Ecologically Relevant Concentrations of Cadmium on the Microbiota, Short-Chain Fatty Acids, and FFAR 2 Expression in Zebrafish. Metabolites 2023; 13:metabo13050657. [PMID: 37233698 DOI: 10.3390/metabo13050657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/27/2023] Open
Abstract
Exposure to cadmium (Cd) can affect neurodevelopment and results in increased potential of developing neurodegenerative diseases during the early developmental stage of organisms, but the mechanisms through which exposure to environmentally relevant concentrations of Cd lead to developmental neurotoxicity remain unclear. Although we know that microbial community fixations overlap with the neurodevelopmental window during early development and that Cd-induced neurodevelopmental toxicity may be related to the disruption of microorganisms during early development, information on the effects of exposure to environmentally relevant Cd concentrations on gut microbiota disruption and neurodevelopment is scarce. Therefore, we established a model of zebrafish exposed to Cd (5 µg/L) to observe the changes in the gut microbiota, SCFAs, and free fatty acid receptor 2 (FFAR2) in zebrafish larvae exposed to Cd for 7 days. Our results indicated that there were significant changes in the gut microbial composition due to the exposure to Cd in zebrafish larvae. At the genus level, there were decreases in the relative abundances of Phascolarctobacterium, Candidatus Saccharimonas, and Blautia in the Cd group. Our analysis revealed that the acetic acid concentration was decreased (p > 0.05) while the isobutyric acid concentration was increased (p < 0.05). Further correlation analysis indicated a positive correlation between the content of acetic acid and the relative abundances of Phascolarctobacterium and Candidatus Saccharimonas (R = 0.842, p < 0.01; R = 0.767, p < 0.01), and a negative correlation between that of isobutyric acid and the relative abundance of Blautia glucerasea (R = -0.673, p < 0.05). FFAR2 needs to be activated by SCFAs to exert physiological effects, and acetic acid is its main ligand. The FFAR2 expression and the acetic acid concentration were decreased in the Cd group. We speculate that FFAR2 may be implicated in the regulatory mechanism of the gut-brain axis in Cd-induced neurodevelopmental toxicity.
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Affiliation(s)
- Jian Yang
- School of Public Health, Guangdong Pharmaceutical University, 283, Jianghaidadao, Guangzhou 510006, China
| | - Junyi Li
- School of Public Health, Guangdong Pharmaceutical University, 283, Jianghaidadao, Guangzhou 510006, China
| | - Xiaoshun Zhang
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Occupational Health and Occupational Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Qin Zhou
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Occupational Health and Occupational Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Junyi Wang
- School of Public Health, Guangdong Pharmaceutical University, 283, Jianghaidadao, Guangzhou 510006, China
| | - Qingsong Chen
- School of Public Health, Guangdong Pharmaceutical University, 283, Jianghaidadao, Guangzhou 510006, China
| | - Xiaojing Meng
- Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Occupational Health and Occupational Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Yuan Xia
- School of Public Health, Guangdong Pharmaceutical University, 283, Jianghaidadao, Guangzhou 510006, China
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11
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Fu J, Li J, Sun Y, Liu S, Song F, Liu Z. In-depth investigation of the mechanisms of Schisandra chinensis polysaccharide mitigating Alzheimer's disease rat via gut microbiota and feces metabolomics. Int J Biol Macromol 2023; 232:123488. [PMID: 36731694 DOI: 10.1016/j.ijbiomac.2023.123488] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 12/24/2022] [Accepted: 01/26/2023] [Indexed: 02/01/2023]
Abstract
Schisandra chinensis (S. chinensis) is an herbal medicine used for the treatment of Alzheimer's disease (AD). The purified polysaccharide fraction, namely SCP2, was previously isolated from S. chinensis crude polysaccharide (SCP) and its structure and in vitro activity were investigated. However, the in vivo activity of SCP2 and its potential mechanism for the treatment of AD have yet to be determined. This study used a combination of microbiomics and metabolomics to comprehensively explore the microbiota and metabolic changes in AD rats under SCP2 intervention, with the aim of elucidating the potential mechanisms of SCP2 in the treatment of AD. SCP2 showed significant therapeutic effects in AD rats, as evidenced by improved learning and memory capacity, reduced neuroinflammation, and restoration of the integrity of the intestinal barrier. Fecal metabolomic and microbiomic analyses revealed that SCP2 significantly modulated 19 endogenous metabolites and reversed gut microbiota disorders in AD rats. Moreover, SCP2 significantly increased the content of short-chain fatty acid (SCFAs) in the AD rats. Correlation analysis showed a significant correlation between gut microbes, metabolites and the content of SCFAs. Collectively, these findings will provide the basis for further development of SCP2.
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Affiliation(s)
- Jun Fu
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China.; Jilin Provincial Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun, Institute of Applied Chemistry, Chinese Academy of Sciences & National Center of Mass Spectrometry in Changchun, Changchun, 130022, China
| | - Jixun Li
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China.; Jilin Provincial Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun, Institute of Applied Chemistry, Chinese Academy of Sciences & National Center of Mass Spectrometry in Changchun, Changchun, 130022, China
| | - Yuzhen Sun
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China.; Jilin Provincial Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun, Institute of Applied Chemistry, Chinese Academy of Sciences & National Center of Mass Spectrometry in Changchun, Changchun, 130022, China
| | - Shu Liu
- Jilin Provincial Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun, Institute of Applied Chemistry, Chinese Academy of Sciences & National Center of Mass Spectrometry in Changchun, Changchun, 130022, China
| | - Fengrui Song
- Jilin Provincial Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun, Institute of Applied Chemistry, Chinese Academy of Sciences & National Center of Mass Spectrometry in Changchun, Changchun, 130022, China
| | - Zhongying Liu
- School of Pharmaceutical Sciences, Jilin University, Changchun 130021, China..
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L K, Ng TKS, Wee HN, Ching J. Gut-brain axis through the lens of gut microbiota and their relationships with Alzheimer's disease pathology: Review and recommendations. Mech Ageing Dev 2023; 211:111787. [PMID: 36736919 DOI: 10.1016/j.mad.2023.111787] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 01/05/2023] [Accepted: 01/30/2023] [Indexed: 02/04/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that affects millions of people worldwide. Growing evidence suggests that the gut microbiome (GM) plays a pivotal role in the pathogenesis of AD through the microbiota-gut-brain axis (MGB). Alterations in GM composition and diversity have been observed in both animal models and in human patients with AD. GM dysbiosis has been implicated in increased intestinal permeability, blood-brain barrier (BBB) impairment, neuroinflammation and the development of hallmarks of AD. Further elucidation of the role of GM in AD could pave way for the development of holistic predictive methods for determining AD risk and progression of disease. Furthermore, accumulating evidence suggests that GM modulation could alleviate adverse symptoms of AD or serve as a preventive measure. In addition, increasing evidence shows that Type 2 Diabetes Mellitus (T2DM) is often comorbid with AD, with common GM alterations and inflammatory response, which could chart the development of GM-related treatment interventions for both diseases. We conclude by exploring the therapeutic potential of GM in alleviating symptoms of AD and in reducing risk. Furthermore, we also propose future directions in AD research, namely fecal microbiota transplantation (FMT) and precision medicine.
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Affiliation(s)
- Krishaa L
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, Singapore
| | - Ted Kheng Siang Ng
- Arizona State University, Edson College of Nursing and Health Innovation, USA.
| | - Hai Ning Wee
- Cardiovascular and Metabolic Disorders Programme, Duke-NUS Medical School, Singapore
| | - Jianhong Ching
- Cardiovascular and Metabolic Disorders Programme, Duke-NUS Medical School, Singapore; KK Research Centre, KK Women's and Children's Hospital, Singapore.
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Ubeda C, Vázquez-Carretero MD, Luque-Tirado A, Ríos-Reina R, Rubio-Sánchez R, Franco-Macías E, García-Miranda P, Calonge ML, Peral MJ. Fecal Volatile Organic Compounds and Microbiota Associated with the Progression of Cognitive Impairment in Alzheimer's Disease. Int J Mol Sci 2022; 24:ijms24010707. [PMID: 36614151 PMCID: PMC9821163 DOI: 10.3390/ijms24010707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/22/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
Metabolites produced by an altered gut microbiota might mediate the effects in the brain. Among metabolites, the fecal volatile organic compounds (VOCs) are considered to be potential biomarkers. In this study, we examined both the VOCs and bacterial taxa in the feces from healthy subjects and Alzheimer's disease (AD) patients at early and middle stages. Remarkably, 29 fecal VOCs and 13 bacterial genera were differentiated from the healthy subjects and the AD patients. In general, higher amounts of acids and esters were found in in the feces of the AD patients and terpenes, sulfur compounds and aldehydes in the healthy subjects. At the early stage of AD, the most relevant VOCs with a higher abundance were short-chain fatty acids and their producing bacteria, Faecalibacterium and Lachnoclostridium. Coinciding with the development of dementia in the AD patients, parallel rises of heptanoic acid and Peptococcus were observed. At a more advanced stage of AD, the microbiota and volatiles shifted towards a profile in the feces with increases in hexanoic acid, Ruminococcus and Blautia. The most remarkable VOCs that were associated with the healthy subjects were 4-ethyl-phenol and dodecanol, together with their possible producers Clostridium and Coprococcus. Our results revealed a VOCs and microbiota crosstalk in AD development and their profiles in the feces were specific depending on the stage of AD. Additionally, some of the most significant fecal VOCs identified in our study could be used as potential biomarkers for the initiation and progression of AD.
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Affiliation(s)
- Cristina Ubeda
- Departamento de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain
| | - María D. Vázquez-Carretero
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain
- Correspondence: (M.D.V.-C.); (P.G.-M.); Tel.: +34-954556777 (M.D.V.-C.); +34-954556777 (P.G.-M.)
| | - Andrea Luque-Tirado
- Unidad de Memoria, Servicio de Neurología, Hospital Universitario Virgen del Rocío, 41013 Sevilla, Spain
| | - Rocío Ríos-Reina
- Departamento de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain
| | - Ricardo Rubio-Sánchez
- Laboratorio de Análisis Clínicos, Hospital Universitario Valme, 41014 Sevilla, Spain
| | - Emilio Franco-Macías
- Unidad de Memoria, Servicio de Neurología, Hospital Universitario Virgen del Rocío, 41013 Sevilla, Spain
| | - Pablo García-Miranda
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain
- Correspondence: (M.D.V.-C.); (P.G.-M.); Tel.: +34-954556777 (M.D.V.-C.); +34-954556777 (P.G.-M.)
| | - María L. Calonge
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain
| | - María J. Peral
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain
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14
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Bacterial DNAemia in Alzheimer's Disease and Mild Cognitive Impairment: Association with Cognitive Decline, Plasma BDNF Levels, and Inflammatory Response. Int J Mol Sci 2022; 24:ijms24010078. [PMID: 36613538 PMCID: PMC9820596 DOI: 10.3390/ijms24010078] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/13/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Microbial dysbiosis (MD) provokes gut barrier alterations and bacterial translocation in the bloodstream. The increased blood bacterial DNA (BB-DNA) may promote peripheral- and neuro-inflammation, contributing to cognitive impairment. MD also influences brain-derived neurotrophic factor (BDNF) production, whose alterations contribute to the etiopathogenesis of Alzheimer's disease (AD). The purpose of this study is to measure BB-DNA in healthy elderly controls (EC), and in patients with mild cognitive impairment (MCI) and AD to explore the effect on plasma BDNF levels (pBDNF), the inflammatory response, and the association with cognitive decline during a two-year follow-up. Baseline BB-DNA and pBDNF were significantly higher in MCI and AD than in EC. BB-DNA was positively correlated with pBDNF in AD, plasma Tumor necrosis factor-alpha (TNF-α), and Interleukin-10 (IL-10) levels in MCI. AD patients with BB-DNA values above the 50th percentile had lower baseline Mini-Mental State Examination (MMSE). After a two-year follow-up, AD patients with the highest BB-DNA tertile had a worse cognitive decline, while higher BB-DNA levels were associated with higher TNF-α and lower IL-10 in MCI. Our study demonstrates that, in early AD, the higher the BB-DNA levels, the higher the pBDNF levels, suggesting a defensive attempt; BB-DNA seems to play a role in the AD severity/progression; in MCI, higher BB-DNA may trigger an increased inflammatory response.
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Zhao Y, Jaber VR, Pogue AI, Sharfman NM, Taylor C, Lukiw WJ. Lipopolysaccharides (LPSs) as Potent Neurotoxic Glycolipids in Alzheimer's Disease (AD). Int J Mol Sci 2022; 23:ijms232012671. [PMID: 36293528 PMCID: PMC9604166 DOI: 10.3390/ijms232012671] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/12/2022] [Accepted: 10/19/2022] [Indexed: 01/11/2023] Open
Abstract
Lipopolysaccharides (LPSs) are microbiome-derived glycolipids that are among the most potent pro-inflammatory neurotoxins known. In Homo sapiens, the major sources of LPSs are gastrointestinal (GI)-tract-resident facultative anaerobic Gram-negative bacilli, including Bacteroides fragilis and Escherichia coli. LPSs have been abundantly detected in aged human brain by multiple independent research investigators, and an increased abundance of LPSs around and within Alzheimer's disease (AD)-affected neurons has been found. Microbiome-generated LPSs and other endotoxins cross GI-tract biophysiological barriers into the systemic circulation and across the blood-brain barrier into the brain, a pathological process that increases during aging and in vascular disorders, including 'leaky gut syndrome'. Further evidence indicates that LPSs up-regulate pro-inflammatory transcription factor complex NF-kB (p50/p65) and subsequently a set of NF-kB-sensitive microRNAs, including miRNA-30b, miRNA-34a, miRNA-146a and miRNA-155. These up-regulated miRNAs in turn down-regulate a family of neurodegeneration-associated messenger RNA (mRNA) targets, including the mRNA encoding the neuron-specific neurofilament light (NF-L) chain protein. While NF-L has been reported to be up-regulated in peripheral biofluids in AD and other progressive and lethal pro-inflammatory neurodegenerative disorders, NF-L is significantly down-regulated within neocortical neurons, and this may account for neuronal atrophy, loss of axonal caliber and alterations in neuronal cell shape, modified synaptic architecture and network deficits in neuronal signaling capacity. This paper reviews and reveals the most current findings on the neurotoxic aspects of LPSs and how these pro-inflammatory glycolipids contribute to the biological mechanism of progressive, age-related and ultimately lethal neurodegenerative disorders. This recently discovered gut-microbiota-derived LPS-NF-kB-miRNA-30b-NF-L pathological signaling network: (i) underscores a direct positive pathological link between the LPSs of GI-tract microbes and the inflammatory neuropathology, disordered cytoskeleton, and disrupted synaptic-signaling of the AD brain and stressed human brain cells in primary culture; and (ii) is the first example of a microbiome-derived neurotoxic glycolipid having significant detrimental miRNA-mediated actions on the expression of NF-L, an abundant filamentous protein known to be important in the maintenance of neuronal and synaptic homeostasis.
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Affiliation(s)
- Yuhai Zhao
- LSU Neuroscience Center, Louisiana State University Health Science Center, New Orleans, LA 70112, USA
- Department of Cell Biology and Anatomy, LSU Health Science Center, New Orleans, LA 70112, USA
| | - Vivian R. Jaber
- LSU Neuroscience Center, Louisiana State University Health Science Center, New Orleans, LA 70112, USA
| | | | - Nathan M. Sharfman
- LSU Neuroscience Center, Louisiana State University Health Science Center, New Orleans, LA 70112, USA
| | - Christopher Taylor
- Department of Microbiology, Immunology & Parasitology, LSU Health Science Center, New Orleans, LA 70112, USA
| | - Walter J. Lukiw
- LSU Neuroscience Center, Louisiana State University Health Science Center, New Orleans, LA 70112, USA
- Alchem Biotech Research, Toronto, ON M5S 1A8, Canada
- Department of Ophthalmology, LSU Health Science Center, New Orleans, LA 70112, USA
- Department Neurology, Louisiana State University Health Science Center, New Orleans, LA 70112, USA
- Correspondence:
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