Regulation of Neurotransmitters by the Gut Microbiota and Effects on Cognition in Neurological Disorders

Nutrients, Journal Year: 2021, Volume and Issue: 13(6), P. 2099 - 2099

Published: June 19, 2021

Emerging evidence indicates that gut microbiota is important in the regulation of brain activity and cognitive functions. Microbes mediate communication among metabolic, peripheral immune, central nervous systems via microbiota–gut–brain axis. However, it not well understood how microbiome neurons mutually interact or these interactions affect normal functioning cognition. We summarize mechanisms whereby regulate production, transportation, neurotransmitters. also discuss dysbiosis affects function, especially neurodegenerative diseases such as Alzheimer’s disease Parkinson’s disease.

Language: Английский

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Immunomodulatory potential of gut microbiome-derived short-chain fatty acids (SCFAs)

Acta Biochimica Polonica, Journal Year: 2019, Volume and Issue: unknown

Published: March 4, 2019

Intestinal microbiota is an element of the bacterial ecosystem in all mammalian organisms. These microorganisms play a very important part development, functioning, and modulation immune system from moment birth. In recent years, owing to use modern sequencing techniques, microbiome composition healthy people has been identified based on 16S rRNA analysis. Currently, more attention being given influence host’s cellular metabolism. Analysis microbial metabolites, among them short-chain fatty acids (SCFAs), disruption intestinal homeostasis terms their effects molecular regulatory mechanisms reactions will surely improve understanding etiology many common diseases. SCFAs, mainly butyrate, propionate, acetate, occur specific amounts, proportions can change, depending diet, age The levels SCFAs are substantially influenced by ratio commensal bacteria, disturbance which (dysbiosis) lead disproportion between produced. regarded as mediators communication system. signal they produce transferred, others, cells via free acid receptors (FFARs), belong family G protein-coupled (GPCRs). It also confirmed that inhibit activity histone deacetylase (HDAC) – enzyme involved post-translational modifications, namely process deacetylation and, what new, crotonylation. properties have effect immunomodulatory potential i.e. maintaining anti/pro-inflammatory balance. act not only locally intestines colonized but cells, modulate response multi-protein inflammasome complexes. contribute maintenance urinary (kidneys), respiratory (lungs), central nervous system, sight organ.

Language: Английский

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Mild cognitive impairment has similar alterations as Alzheimer's disease in gut microbiota

Alzheimer s & Dementia, Journal Year: 2019, Volume and Issue: 15(10), P. 1357 - 1366

Published: Aug. 18, 2019

Abstract Objective Gut microbiota changes before the onset of Alzheimer's disease (AD) and alterations could be detected in stage mild cognitive impairment (MCI). The findings might offer diagnostic biomarkers dementia. Background AD is most common cause dementia, MCI predementia state. Recent studies suggest gut microbial communities associated with AD, whereas dementia has not been discovered characterized humans. New/Updated Hypothesis We hypothesize that dysbiosis happens stage. Patients have decreased diversity, for early detection AD. In our preliminary study, we identified differences between normal controls 11 genera from feces blood. No difference was detected. Using model fecal samples all different input, 93% (28 30) patients correctly. Major Challenges diagnosis study based on symptoms neuroimaging, should included precise further validating studies. Besides, as longitudinally, their relationship progress needs to studied prospective Linkage Other Theories Escherichia observed increased at genus level both blood MCI. For biomarker, postmortem brain tissue showed lipopolysaccharides gram‐negative coli fragments colocalize amyloid plaque. this way, pathogenesis would triggered during by shifting. systemic inflammatory reactions caused compounds secreted bacteria may impair blood‐brain barrier promote neuroinflammation and/or neurodegeneration. Furthermore, abnormal metabolites gene functions an impact

Language: Английский

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The Gut Microbiome, Aging, and Longevity: A Systematic Review

Nutrients, Journal Year: 2020, Volume and Issue: 12(12), P. 3759 - 3759

Published: Dec. 7, 2020

Aging is determined by complex interactions among genetic and environmental factors. Increasing evidence suggests that the gut microbiome lies at core of many age-associated changes, including immune system dysregulation susceptibility to diseases. The microbiota undergoes extensive changes across lifespan, age-related processes may influence its related metabolic alterations. aim this systematic review was summarize current literature on aging-associated alterations in diversity, composition, functional features microbiota. We identified 27 empirical human studies normal successful aging suitable for inclusion. Alpha diversity microbial taxa, pathways, metabolites higher older adults, particularly oldest-old compared younger individuals. Beta distances significantly differed various developmental stages were different even between younger-old adults. Differences taxonomic composition potential varied studies, but Akkermansia most consistently reported be relatively more abundant with aging, whereas Faecalibacterium, Bacteroidaceae, Lachnospiraceae reduced. Older adults have reduced pathways carbohydrate metabolism amino acid synthesis; however, exhibited differences distinguished their from young-old such as greater short-chain fatty production increased butyrate derivatives. Although a definitive interpretation limited cross-sectional design published reports, we integrated findings downstream metabolites, offering possible explanations regarding processes.

Language: Английский

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Gut Microbiota, Muscle Mass and Function in Aging: A Focus on Physical Frailty and Sarcopenia

Nutrients, Journal Year: 2019, Volume and Issue: 11(7), P. 1633 - 1633

Published: July 17, 2019

Human gut microbiota is able to influence the host physiology by regulating multiple processes, including nutrient absorption, inflammation, oxidative stress, immune function, and anabolic balance. Aging associated with reduced biodiversity, increased inter-individual variability, over-representation of pathobionts, these phenomena may have great relevance for skeletal muscle mass function. For this reason, presence a gut-muscle axis onset progression age-related physical frailty sarcopenia has been recently hypothesized. In narrative review, we summarize studies supporting possible association between microbiota-related parameters measures mass, performance in animal models humans. Reduced distinct composition fermentative capacity mice, administration probiotics or butyrate mouse wasting improved mass. However, no targeted human microbiome sarcopenia. Limited evidence from shows an composition, involving key taxa such as Faecalibacterium Bifidobacterium, grip strength. Similarly, few conducted on patients parkinsonism showed trend towards different those gait speed. No assessed fecal other performance. several studies, mainly cross-sectional design, suggest frailty, mostly according deficit accumulation model. Namely, was lower representation butyrate-producing bacteria. Therefore, conclude that causal link fitness still uncertain due lack large number covariates, diet, exercise, multimorbidity, polypharmacy, both function older age. relationship remains very promising area research future.

Language: Английский

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Inflammation From Peripheral Organs to the Brain: How Does Systemic Inflammation Cause Neuroinflammation?

Frontiers in Aging Neuroscience, Journal Year: 2022, Volume and Issue: 14

Published: June 16, 2022

As inflammation in the brain contributes to several neurological and psychiatric diseases, cause of neuroinflammation is being widely studied. The causes can be roughly divided into following domains: viral infection, autoimmune disease, from peripheral organs, mental stress, metabolic disorders, lifestyle. In particular, effects caused by organs have yet unclear mechanisms. Many such as gastrointestinal inflammation, chronic obstructive pulmonary rheumatoid arthritis, dermatitis, fatigue syndrome, or myalgic encephalomyelitis (CFS/ME), trigger through pathways. mechanisms action for inflammation-induced include disruption blood-brain barrier, activation glial cells associated with systemic immune activation, on autonomic nerves via organ-brain axis. this review, we consider previous studies relationship between neuroinflammation, focusing regions susceptible inflammation.

Language: Английский

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Dysbiosis, gut barrier dysfunction and inflammation in dementia: a pilot study

BMC Geriatrics, Journal Year: 2020, Volume and Issue: 20(1)

Published: July 20, 2020

Abstract Background Dementia is an increasing public health threat worldwide. The pathogenesis of dementia has not been fully elucidated yet. Inflammatory processes are hypothesized to play important role as a driver for cognitive decline but the origin inflammation clear. We hypothesize that disturbances in gut microbiome composition, barrier dysfunction, bacterial translocation and resulting associated with dysfunction dementia. Methods To test this hypothesis, cohort 23 patients 18 age sex matched controls without impairments were studied. Gut assessed from stool serum samples. Malnutrition was by Mini Nutritional Assessment Short Form (MNA-SF), detailed information on drug use collected. Microbiome composition 16S rRNA sequencing, QIIME 2 Calypso 7.14 tools. Results dysbiosis characterized differences beta diversity changes taxonomic composition. permeability increased evidenced diamine oxidase (DAO) levels systemic confirmed soluble cluster differentiation 14 (sCD14). BMI statin had strongest impact Conclusion biomarkers inflammation. Lachnospiraceae NK4A136 group potential butyrate producer reduced intake factors, Increasing producing bacteria targeting malnutrition may be promising therapeutic targets Trial registration NCT03167983 .

Language: Английский

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Microbial-derived metabolites as a risk factor of age-related cognitive decline and dementia

Molecular Neurodegeneration, Journal Year: 2022, Volume and Issue: 17(1)

Published: June 17, 2022

A consequence of our progressively ageing global population is the increasing prevalence worldwide age-related cognitive decline and dementia. In absence effective therapeutic interventions, identifying risk factors associated with becomes increasingly vital. Novel perspectives suggest that a dynamic bidirectional communication system between gut, its microbiome, central nervous system, commonly referred to as microbiota-gut-brain axis, may be contributing factor for health disease. However, exact mechanisms remain undefined. Microbial-derived metabolites produced in gut can cross intestinal epithelial barrier, enter systemic circulation trigger physiological responses both directly indirectly affecting functions. Dysregulation this (i.e., dysbiosis) modulate cytotoxic metabolite production, promote neuroinflammation negatively impact cognition. review, we explore critical connections microbial-derived (secondary bile acids, trimethylamine-N-oxide (TMAO), tryptophan derivatives others) their influence upon function neurodegenerative disorders, particular interest less-explored role decline.

Language: Английский

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Association between physical activity and changes in intestinal microbiota composition: A systematic review

PLoS ONE, Journal Year: 2021, Volume and Issue: 16(2), P. e0247039 - e0247039

Published: Feb. 25, 2021

Introduction The intestinal microbiota comprises bacteria, fungi, archaea, protists, helminths and viruses that symbiotically inhabit the digestive system. To date, research has provided limited data on possible association between an active lifestyle a healthy composition of human microbiota. This review was aimed to summarize results studies comparing microbiome individuals with different physical activity amounts. Methods We searched Medline/Ovid, NIH/PubMed, Academic Search Complete August–October 2020. Inclusion criteria comprised: (a) cross-sectional focused gut among subjects levels; (b) describing responses any type exercise stimulus; (c) containing adult women men. excluded diet modifications, probiotic or prebiotic consumption, as well diabetes, hypertension, cancer, hormonal dysfunction. Methodological quality risk bias for each study were assessed using Risk Of Bias In Non-randomized Studies—of Interventions tool. from longitudinal are shown independently. Results A total 17 articles eligible inclusion: ten seven studies. Main outcomes vary significantly according amounts in identified discrete changes diversity indexes relative abundance certain bacteria people. Conclusion As literature this field is rapidly growing, it important incorporate diverse methods evaluate other aspects related lifestyles such sleep dietary patterns. Exploration groups viruses, archaea parasites may lead better understanding adaptation sports its potentially beneficial effects host metabolism endurance.

Language: Английский

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An update on cognitive frailty: Its definition, impact, associated factors and underlying mechanisms, and interventions

Geriatrics and gerontology international/Geriatrics & gerontology international, Journal Year: 2021, Volume and Issue: 22(2), P. 99 - 109

Published: Dec. 9, 2021

Since the concept and operational definition of “cognitive frailty” (simultaneous presence physical frailty cognitive impairment without concurrent dementia) were proposed by International Academy Nutrition Aging Association Gerontology Geriatrics, has been widely investigated. This review is intended to address frailty, its consequences, contributing factors underlying mechanisms, as well interventions for frailty. Although definitions assessments vary among researchers, older adults with both are shown be at higher risk adverse health outcomes, including death, disability, hospitalization incident dementia, than those either condition alone. While mechanisms still unclear, associated include sociodemographic factors, social status, nutritional geriatric syndrome, activities, functional comorbidities, medication use, gut‐derived metabolites structural changes in brain. Accumulating evidence indicates need comprehensive assessment that helps identify possible causes develop a multimodal individualized intervention prevent outcomes Further studies required clarify through which interact accelerate particularly outcomes. In addition, an effective flow diagram from primary screening multidimensional needs developed future implementation clinical community settings. Geriatr Gerontol Int 2022; 22: 99–109 .

Language: Английский

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