Gut microbiota in health and disease: an overview focused on metabolic inflammation

2016 ◽  
Vol 7 (2) ◽  
pp. 181-194 ◽  
Author(s):  
R. Nagpal ◽  
M. Kumar ◽  
A.K. Yadav ◽  
R. Hemalatha ◽  
H. Yadav ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Gut Microbiota ◽  
Intestinal Barrier ◽  
Adverse Outcomes ◽  
Special Focus ◽  
Low Grade ◽  
Immune Functions ◽  
Metabolic Inflammation

In concern to the continuously rising global prevalence of obesity, diabetes and associated diseases, novel preventive and therapeutic approaches are urgently required. However, to explore and develop such innovative strategies, a meticulous comprehension of the biological basis of these diseases is extremely important. Past decade has witnessed an enormous amount of research investigation and advancement in the field of obesity, diabetes and metabolic syndrome, with the gut microbiota receiving a special focus in the triangle of nutrition, health and diseases. In particular, the role of gut microbiota in health and diseases has been one of the most vigorous and intriguing field of recent research; however, much still remains to be elucidated about its precise role in host metabolism and immune functions and its implication in the onset, progression as well as in the amelioration of metabolic ailments. Recent investigations have suggested a significant contribution of the gut microbiota in the regulation and impairment of energy homeostasis, thereby causing metabolic disorders, such as metabolic endotoxemia, insulin resistance and type 2 diabetes. Numerous inflammatory biomarkers have been found to be associated with obesity, diabetes and risk of other associated adverse outcomes, thereby suggesting that a persistent low-grade inflammatory response is a potential risk factor. In this milieu, this review intends to discuss potential evidences supporting the disturbance of the gut microbiota balance and the intestinal barrier permeability as a potential triggering factor for systemic inflammation in the onset and progression of obesity, type 2 diabetes and metabolic syndrome.

scholarly journals Cardiac Autonomic Neuropathy: A Progressive Consequence of Chronic Low-Grade Inflammation in Type 2 Diabetes and Related Metabolic Disorders

2020 ◽  
Vol 21 (23) ◽  
pp. 9005
Author(s):  
Nour-Mounira Z. Bakkar ◽  
Haneen S. Dwaib ◽  
Souha Fares ◽  
Ali H. Eid ◽  
Yusra Al-Dhaheri ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Autonomic Neuropathy ◽  
Experimental Models ◽  
Cardiac Autonomic Neuropathy ◽  
Low Grade ◽  
Metabolic Inflammation ◽  
The Metabolic Syndrome ◽  
Cardiovascular Morbidity And Mortality

Cardiac autonomic neuropathy (CAN) is one of the earliest complications of type 2 diabetes (T2D), presenting a silent cause of cardiovascular morbidity and mortality. Recent research relates the pathogenesis of cardiovascular disease in T2D to an ensuing chronic, low-grade proinflammatory and pro-oxidative environment, being the hallmark of the metabolic syndrome. Metabolic inflammation emerges as adipose tissue inflammatory changes extending systemically, on the advent of hyperglycemia, to reach central regions of the brain. In light of changes in glucose and insulin homeostasis, dysbiosis or alteration of the gut microbiome (GM) emerges, further contributing to inflammatory processes through increased gut and blood–brain barrier permeability. Interestingly, studies reveal that the determinants of oxidative stress and inflammation progression exist at the crossroad of CAN manifestations, dictating their evolution along the natural course of T2D development. Indeed, sympathetic and parasympathetic deterioration was shown to correlate with markers of adipose, vascular, and systemic inflammation. Additionally, evidence points out that dysbiosis could promote a sympatho-excitatory state through differentially affecting the secretion of hormones and neuromodulators, such as norepinephrine, serotonin, and γ-aminobutyric acid, and acting along the renin–angiotensin–aldosterone axis. Emerging neuronal inflammation and concomitant autophagic defects in brainstem nuclei were described as possible underlying mechanisms of CAN in experimental models of metabolic syndrome and T2D. Drugs with anti-inflammatory characteristics provide potential avenues for targeting pathways involved in CAN initiation and progression. The aim of this review is to delineate the etiology of CAN in the context of a metabolic disorder characterized by elevated oxidative and inflammatory load.

scholarly journals Intestinal microbiota and their metabolic contribution to type 2 diabetes and obesity

2021 ◽  
Author(s):  
A. L. Cunningham ◽  
J. W. Stephens ◽  
D. A. Harris
Keyword(s):  
Type 2 Diabetes ◽  
Gut Microbiota ◽  
Current Knowledge ◽  
Intestinal Barrier ◽  
Short Chain Fatty Acids ◽  
Global Epidemic ◽  
Technological Advances ◽  
Diabetes And Obesity

AbstractObesity and type 2 diabetes mellitus (T2DM) are common, chronic metabolic disorders with associated significant long-term health problems at global epidemic levels. It is recognised that gut microbiota play a central role in maintaining host homeostasis and through technological advances in both animal and human models it is becoming clear that gut microbiota are heavily involved in key pathophysiological roles in the aetiology and progression of both conditions. This review will focus on current knowledge regarding microbiota interactions with short chain fatty acids, the host inflammatory response, signaling pathways, integrity of the intestinal barrier, the interaction of the gut-brain axis and the subsequent impact on the metabolic health of the host.

scholarly journals Differences in gut microbiota composition in metabolic syndrome and type 2 diabetes subjects in a multi-ethnic population: the HELIUS study

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Mélanie Deschasaux ◽  
Kristien Bouter ◽  
Andrei Prodan ◽  
Evgeni Levin ◽  
Albert Groen ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Gut Microbiota ◽  
Ethnic Groups ◽  
Alpha Diversity ◽  
Microbiota Composition ◽  
Ethnic Population ◽  
Metabolic State ◽  
Gut Microbiota Composition

AbstractRecently, increased attention has been drawn to the composition of the intestinal microbiota and its possible role in metabolic syndrome and type 2 diabetes (T2DM). However, potential variation in gut microbiota composition across ethnic groups is rarely considered despite observed unequal prevalence for these diseases. Our objective was therefore to study the gut microbiota composition across health, metabolic syndrome and T2DM in a multi-ethnic population residing in the same geographical area. 16S rRNA gene sequencing was performed on fecal samples from 3926 participants to the HELIUS cohort (Amsterdam, The Netherlands), representing 6 ethnic groups (Dutch, Ghanaians, Moroccans, Turks, Surinamese of either African or South-Asian descent). Included participants completed a questionnaire and underwent a physical examination and overnight fasted blood sampling. Gut microbiota composition was compared across metabolic status (diabetes with and without metformin use, metabolic syndrome and its subsequent components, health) and ethnicities using Wilcoxon-Mann-Withney tests and logistic regressions. Overall, the gut microbiota alpha-diversity (richness, Shannon index and phylogenetic diversity) decreased with worsening of the metabolic state (comparing health to metabolic syndrome to T2DM) but this was only partially reproduced in ethnic-specific analyses. In line, a lower alpha-diversity was found in relation to all metabolic syndrome components as well as in T2DM subjects using metformin compared to non-users. Alterations, mainly decreased abundances, were also observed at the genus level (many Clostridiales) in metabolic syndrome subjects and more strongly in T2DM subjects with differences across ethnic groups. In particular, we observed decreased abundances of members of the Peptostreptococcaceae family and of Turicibacter and an increased abundance of a member of the Enterobacteriaceae family. Our data highlight several compositional differences in the gut microbiota of individuals with metabolic syndrome or T2DM. These features, confirming prior observations, give some insights into potential key intestinal bacteria related to a worsening of metabolic state. Our results also underscore possible ethnic-specific profiles associated with these microbiota alterations that should be further explored.

scholarly journals Amelioration of metabolic syndrome by metformin associates with reduced indices of low-grade inflammation independently of the gut microbiota

2019 ◽  
Vol 317 (6) ◽  
pp. E1121-E1130 ◽  
Author(s):  
Aneseh Adeshirlarijaney ◽  
Jun Zou ◽  
Hao Q. Tran ◽  
Benoit Chassaing ◽  
Andrew T. Gewirtz
Keyword(s):  
Metabolic Syndrome ◽  
Gut Microbiota ◽  
Early Stage ◽  
Mechanisms Of Action ◽  
Low Grade ◽  
Inflammatory Agent ◽  
Frontline Treatment ◽  
Anti Inflammatory ◽  
Low Grade Inflammation

Metformin beneficially impacts several aspects of metabolic syndrome including dysglycemia, obesity, and liver dysfunction, thus making it a widely used frontline treatment for early-stage type 2 diabetes, which is associated with these disorders. Several mechanisms of action for metformin have been proposed, including that it acts as an anti-inflammatory agent, possibly as a result of its impact on intestinal microbiota. In accord with this possibility, we observed herein that, in mice with diet-induced metabolic syndrome, metformin impacts the gut microbiota by preventing its encroachment upon the host, a feature of metabolic syndrome in mice and humans. However, the ability of metformin to beneficially impact metabolic syndrome in mice was not markedly altered by reduction or elimination of gut microbiota, achieved by the use of antibiotics or germfree mice. Although reducing or eliminating microbiota by itself suppressed diet-induced dysglycemia, other features of metabolic syndrome including obesity, hepatic steatosis, and low-grade inflammation remained suppressed by metformin in the presence or absence of gut microbiota. These results support a role for anti-inflammatory activity of metformin, irrespective of gut microbiota, in driving some of the beneficial impacts of this drug on metabolic syndrome.

scholarly journals Impact of botanical fermented foods on metabolic biomarkers and gut microbiota in adults with metabolic syndrome and type 2 diabetes: a systematic review protocol

BMJ Open ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. e029242 ◽  
Author(s):  
Miin Chan ◽  
Helen Baxter ◽  
Nadja Larsen ◽  
Lene Jespersen ◽  
Elif I Ekinci ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Gut Microbiota ◽  
Inflammatory Markers ◽  
Grey Literature ◽  
Common Finding ◽  
Control Group ◽  
Fermented Foods ◽  
Metabolic Biomarkers

IntroductionDysfunctional gut microbiota is a common finding in patients with metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM). Recent clinical trials have assessed whether botanical fermented foods (BFFs) have beneficial effects on metabolic biomarkers, inflammatory markers and gut microbiota. The aim of this review is to critically evaluate all randomised controlled trials (RCTs) of BFF for evidence of impact on the outcome measures of these disease states.Methods and analysisFour electronic databases (Embase, MEDLINE, CENTRAL and Google Scholar) as well as the grey literature will be searched from inception to present without language or publication status restrictions applied. Eligible RCTs which have enrolled adult participants with T2DM, any MetS components or combinations of these components, treated prophylactically or therapeutically with any botanical fermented food intervention, compared with a control group (no intervention, placebo or active control) will be assessed. Primary outcomes are related to the target conditions, including metabolic biomarkers, inflammatory markers and gut microbiota composition/function. Using Covidence, two independent investigators will conduct title and abstract screening, followed by full-text screening to identify appropriate studies. Methodological quality of the trials will be assessed using the Cochrane risk of bias assessment tool. Findings will be summarised with a narrative synthesis of the differences between included studies. A meta-analysis will be conducted if sufficient data are obtained.Ethics and disseminationEthical approval is not required as primary data will not be collected. Results will be disseminated through peer-reviewed publication, conference presentations and press.PROSPERO registration numberCRD42018117766

scholarly journals Peroxisome Proliferator-Activated Receptor γ and Adipose Tissue—Understanding Obesity-Related Changes in Regulation of Lipid and Glucose Metabolism

2006 ◽  
Vol 92 (2) ◽  
pp. 386-395 ◽  
Author(s):  
Arya M. Sharma ◽  
Bart Staels
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Endocrine Function ◽  
Low Grade ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

Abstract Context: Adipose tissue is a metabolically dynamic organ, serving as a buffer to control fatty acid flux and a regulator of endocrine function. In obese subjects, and those with type 2 diabetes or the metabolic syndrome, adipose tissue function is altered (i.e. adipocytes display morphological differences alongside aberrant endocrine and metabolic function and low-grade inflammation). Evidence Acquisition: Articles on the role of peroxisome proliferator-activated receptor γ (PPARγ) in adipose tissue of healthy individuals and those with obesity, metabolic syndrome, or type 2 diabetes were sourced using MEDLINE (1990–2006). Evidence Synthesis: Articles were assessed to provide a comprehensive overview of how PPARγ-activating ligands improve adipose tissue function, and how this links to improvements in insulin resistance and the progression to type 2 diabetes and atherosclerosis. Conclusions: PPARγ is highly expressed in adipose tissue, where its activation with thiazolidinediones alters fat topography and adipocyte phenotype and up-regulates genes involved in fatty acid metabolism and triglyceride storage. Furthermore, PPARγ activation is associated with potentially beneficial effects on the expression and secretion of a range of factors, including adiponectin, resistin, IL-6, TNFα, plasminogen activator inhibitor-1, monocyte chemoattractant protein-1, and angiotensinogen, as well as a reduction in plasma nonesterified fatty acid supply. The effects of PPARγ also extend to macrophages, where they suppress production of inflammatory mediators. As such, PPARγ activation appears to have a beneficial effect on the relationship between the macrophage and adipocyte that is distorted in obesity. Thus, PPARγ-activating ligands improve adipose tissue function and may have a role in preventing progression of insulin resistance to diabetes and endothelial dysfunction to atherosclerosis.

scholarly journals MECHANISMS IN ENDOCRINOLOGY: Gut microbiota in patients with type 2 diabetes mellitus

2015 ◽  
Vol 172 (4) ◽  
pp. R167-R177 ◽  
Author(s):  
Kristine H Allin ◽  
Trine Nielsen ◽  
Oluf Pedersen
Keyword(s):  
Type 2 Diabetes ◽  
Gut Microbiota ◽  
Metabolic Diseases ◽  
Short Chain Fatty Acids ◽  
Intestinal Content ◽  
Low Grade ◽  
Bacterial Fermentation ◽  
Underlying Mechanisms

Perturbations of the composition and function of the gut microbiota have been associated with metabolic disorders including obesity, insulin resistance and type 2 diabetes. Studies on mice have demonstrated several underlying mechanisms including host signalling through bacterial lipopolysaccharides derived from the outer membranes of Gram-negative bacteria, bacterial fermentation of dietary fibres to short-chain fatty acids and bacterial modulation of bile acids. On top of this, an increased permeability of the intestinal epithelium may lead to increased absorption of macromolecules from the intestinal content resulting in systemic immune responses, low-grade inflammation and altered signalling pathways influencing lipid and glucose metabolism. While mechanistic studies on mice collectively support a causal role of the gut microbiota in metabolic diseases, the majority of studies in humans are correlative of nature and thus hinder causal inferences. Importantly, several factors known to influence the risk of type 2 diabetes, e.g. diet and age, have also been linked to alterations in the gut microbiota complicating the interpretation of correlative studies. However, based upon the available evidence, it is hypothesised that the gut microbiota may mediate or modulate the influence of lifestyle factors triggering development of type 2 diabetes. Thus, the aim of this review is to critically discuss the potential role of the gut microbiota in the pathophysiology and pathogenesis of type 2 diabetes.

Microbiota and epigenetic regulation of inflammatory mediators in type 2 diabetes and obesity

2014 ◽  
Vol 5 (1) ◽  
pp. 33-43 ◽  
Author(s):  
M. Remely ◽  
E. Aumueller ◽  
D. Jahn ◽  
B. Hippe ◽  
H. Brath ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Gut Microbiota ◽  
Epigenetic Regulation ◽  
Control Group ◽  
Low Grade ◽  
Type 2 Diabetics ◽  
Significant Difference

Metabolic syndrome is associated with alterations in the structure of the gut microbiota leading to low-grade inflammatory responses. An increased penetration of the impaired gut membrane by bacterial components is believed to induce this inflammation, possibly involving epigenetic alteration of inflammatory molecules such as Toll-like receptors (TLRs). We evaluated changes of the gut microbiota and epigenetic DNA methylation of TLR2 and TLR4 in three groups of subjects: type 2 diabetics under glucagon-like peptide-1 agonist therapy, obese individuals without established insulin resistance, and a lean control group. Clostridium cluster IV, Clostridium cluster XIVa, lactic acid bacteria, Faecalibacterium prausnitzii and Bacteroidetes abundances were analysed by PCR and 454 high-throughput sequencing. The epigenetic methylation in the regulatory region of TLR4 and TLR2 was analysed using bisulfite conversion and pyrosequencing. We observed a significantly higher ratio of Firmicutes/ Bacteroidetes in type 2 diabetics compared to lean controls and obese. Major differences were shown in lactic acid bacteria, with the highest abundance in type 2 diabetics, followed by obese and lean participants. In comparison, F. prausnitzii was least abundant in type 2 diabetics, and most abundant in lean controls. Methylation analysis of four CpGs in the first exon of TLR4 showed significantly lower methylation in obese individuals, but no significant difference between type 2 diabetics and lean controls. Methylation of seven CpGs in the promoter region of TLR2 was significantly lower in type 2 diabetics compared to obese subjects and lean controls. The methylation levels of both TLRs were significantly correlated with body mass index. Our data suggest that changes in gut microbiota and thus cell wall components are involved in the epigenetic regulation of inflammatory reactions. An improved diet targeted to induce gut microbial balance and in the following even epigenetic changes of pro-inflammatory genes may be effective in the prevention of metabolic syndrome.

scholarly journals Plasma extracellular vesicles in people living with HIV and type 2 diabetes are related to microbial translocation and cardiovascular risk

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beate Vestad ◽  
Tuula A. Nyman ◽  
Malene Hove-Skovsgaard ◽  
Maria Stensland ◽  
Hedda Hoel ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Cardiovascular Risk ◽  
Gut Microbiota ◽  
Extracellular Vesicles ◽  
Microbial Translocation ◽  
Size Exclusion ◽  
Disease Genes ◽  
People Living With Hiv ◽  
Low Grade

AbstractHIV and type 2 diabetes (T2D) are both associated with gut microbiota alterations, low-grade endotoxemia and increased cardiovascular risk. We investigated the potential role of plasma extracellular vesicles (EVs) in relation to these processes. Plasma EVs were isolated by size exclusion chromatography in fasting individuals with HIV and T2D (n = 16), T2D only (n = 14), HIV only (n = 20) or healthy controls (n = 19), and characterized by transmission electron microscopy, western blot, nanoparticle tracking analysis and quantitative proteomics. The findings were compared to gut microbiota alterations, lipopolysaccharide levels and cardiovascular risk profile. Individuals with concomitant HIV and T2D had higher plasma EV concentration, which correlated closely with plasma lipopolysaccharides, triglycerides and Framingham score, but not with gut microbiota alterations. Proteomic analyses identified 558 human proteins, largely related to cardiometabolic disease genes and upstream regulation of inflammatory pathways, including IL-6 and IL-1β, as well as 30 bacterial proteins, mostly from lipopolysaccharide-producing Proteobacteria. Our study supports that EVs are related to microbial translocation processes in individuals with HIV and T2D. Their proteomic content suggests a contributing role in low-grade inflammation and cardiovascular risk development. The present approach for exploring gut-host crosstalk can potentially identify novel diagnostic biomarkers and therapeutic targets.

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