scholarly journals The Gut Microbiota: How Does It Influence the Development and Progression of Liver Diseases

Biomedicines ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 501
Author(s):  
Paulraj Kanmani ◽  
Kanmani Suganya ◽  
Hojun Kim
Keyword(s):  
Gut Microbiota ◽  
Liver Diseases ◽  
Intestinal Inflammation ◽  
Lipoteichoic Acid ◽  
Short Chain Fatty Acids ◽  
Bidirectional Relationship ◽  
Host Health ◽  
Cellular Components ◽  
Gut Microbiota Composition

The gut–liver axis plays important roles in both the maintenance of a healthy liver and the pathogenesis of liver diseases, where the gut microbiota acts as a major determinant of this relationship. Gut bacteria-derived metabolites and cellular components are key molecules that affect the function of the liver and modulate the pathology of liver diseases. Accumulating evidence showed that gut microbiota produces a myriad of molecules, including lipopolysaccharide, lipoteichoic acid, peptidoglycan, and DNA, as well as short-chain fatty acids, bile acids, trimethylamine, and indole derivatives. The translocation of these components to the liver exerts beneficial or pathogenic effects by interacting with liver immune cells. This is a bidirectional relationship. Therefore, the existence of crosstalk between the gut and liver and its implications on host health and diseases are essential for the etiology and treatment of diseases. Several mechanisms have been proposed for the pathogenesis of liver diseases, but still, the mechanisms behind the pathogenic role of gut-derived components on liver pathogenesis remain elusive and not understandable. This review discusses the current progress on the gut microbiota and its components in terms of the progression of liver diseases, and in turn, how liver diseases indirectly affect the intestinal function and induce intestinal inflammation. Moreover, this paper highlights the current therapeutic and preventive strategies used to restore the gut microbiota composition and improve host health.

Gut microbiota modulates COPD pathogenesis: role of anti-inflammatory Parabacteroides goldsteinii lipopolysaccharide

Gut ◽  
2021 ◽  
pp. gutjnl-2020-322599
Author(s):  
Hsin-Chih Lai ◽  
Tzu-Lung Lin ◽  
Ting-Wen Chen ◽  
Yu-Lun Kuo ◽  
Chih-Jung Chang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Intestinal Inflammation ◽  
Chronic Obstructive ◽  
Microbiota Composition ◽  
Active Components ◽  
Toll Like Receptor 4 ◽  
Obstructive Pulmonary Disease ◽  
Anti Inflammatory ◽  
Gut Microbiota Composition

ObjectiveChronic obstructive pulmonary disease (COPD) is a global disease characterised by chronic obstruction of lung airflow interfering with normal breathing. Although the microbiota of respiratory tract is established to be associated with COPD, the causality of gut microbiota in COPD development is not yet established. We aimed to address the connection between gut microbiota composition and lung COPD development, and characterise bacteria and their derived active components for COPD amelioration.DesignA murine cigarette smoking (CS)-based model of COPD and strategies evaluating causal effects of microbiota were performed. Gut microbiota structure was analysed, followed by isolation of target bacterium. Single cell RNA sequencing, together with sera metabolomics analyses were performed to identify host responsive molecules. Bacteria derived active component was isolated, followed by functional assays.ResultsGut microbiota composition significantly affects CS-induced COPD development, and faecal microbiota transplantation restores COPD pathogenesis. A commensal bacterium Parabacteroides goldsteinii was isolated and shown to ameliorate COPD. Reduction of intestinal inflammation and enhancement of cellular mitochondrial and ribosomal activities in colon, systematic restoration of aberrant host amino acids metabolism in sera, and inhibition of lung inflammations act as the important COPD ameliorative mechanisms. Besides, the lipopolysaccharide derived from P. goldsteinii is anti-inflammatory, and significantly ameliorates COPD by acting as an antagonist of toll-like receptor 4 signalling pathway.ConclusionThe gut microbiota–lung COPD axis was connected. A potentially benefial bacterial strain and its functional component may be developed and used as alternative agents for COPD prevention or treatment.

scholarly journals Gut microbiota in obese patients and after bariatric surgery

2019 ◽  
Vol 13 (1) ◽  
pp. 5-16
Author(s):  
Lilit V. Egshatyan ◽  
Dana A. Kushkhanashkhova ◽  
Ekaterina S. Ermilova ◽  
Rashid G. Askerkhanov
Keyword(s):  
Bariatric Surgery ◽  
Gut Microbiota ◽  
Intestinal Microflora ◽  
Bowel Function ◽  
Short Chain Fatty Acids ◽  
Obese Patients ◽  
Qualitative And Quantitative ◽  
Sustained Weight Loss ◽  
Host Health

In this review are discussed experimental and clinical data about the role of gut microbiota and its changes after bariatric surgery. To date, bariatric surgery represents the only treatment that enables substantial and sustained weight loss. The large intestinal microbiota plays an important role in normal bowel function and the maintenance of host health through the formation of short chain fatty acids, modulation of immune system reactivity, and development of colonization resistance. The intestinal microflora is a peculiar indicator of the condition of a microorganism reacting to age, physiological, dietary, and geographical factors from change of qualitative and quantitative structure. Studies have demonstrated that obesity and metabolic syndrome may be associated with profound microbiotal changes. This Review outlines the potential mechanisms by which the major changes in the digestive tract after bariatric surgery can affect the gut microbiota.

scholarly journals The changes of gut microbiota associated with age and lifestyle

2015 ◽  
Vol 12 (2) ◽  
pp. 3-9
Author(s):  
Lilit Vanikovna Egshatyan ◽  
Olga Nikolaevna Tkacheva ◽  
Lyudmila Ivanovna Kafarskaya ◽  
Andrey Nikolaevich Shkoporov ◽  
Aleksandr Viktorovich Tyakht
Keyword(s):  
Gut Microbiota ◽  
Accelerated Aging ◽  
Bowel Function ◽  
Short Chain Fatty Acids ◽  
Qualitative And Quantitative ◽  
Increased Risk ◽  
Host Health ◽  
Normal Metabolism ◽  
Metabolic Endotoxemia

In this review are discussed experimental and clinical data about the role of gut microbiota and its changes associated with age and lifestyle. The large intestinal microbiota plays an important role in normal bowel function and the maintenance of host health through the formation of short chain fatty acids, modulation of immune system reactivity, and development of colonization resistance. The intestinal microflora is a peculiar indicator of the condition of a microorganism reacting to age, physiological, dietary, and geographical factors from change of qualitative and quantitative structure. Studies have demonstrated that obesity and metabolic syndrome may be associated with profound microbiotal changes. Changes in gut microbiota control metabolic endotoxemia - induced chronic inflammation, oxidative stress, and metabolic disorder which are connected with the increased risk of development of cardiovascular diseases and pathology associated with age, which leads to accelerated aging. It is obvious that maintenance of a homeostasis and a normal metabolism is impossible without restoration of a variety of normal associations of intestinal microorganisms.

scholarly journals The Gut-Liver Axis in Health and Disease: The Role of Gut Microbiota-Derived Signals in Liver Injury and Regeneration

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhipeng Zheng ◽  
Baohong Wang
Keyword(s):  
Liver Injury ◽  
Gut Microbiota ◽  
Liver Regeneration ◽  
Liver Diseases ◽  
Molecular Mechanisms ◽  
Short Chain Fatty Acids ◽  
Pathophysiological Process ◽  
Tryptophan Metabolites ◽  
Health And Disease

Diverse liver diseases undergo a similar pathophysiological process in which liver regeneration follows a liver injury. Given the important role of the gut-liver axis in health and diseases, the role of gut microbiota-derived signals in liver injury and regeneration has attracted much attention. It has been observed that the composition of gut microbiota dynamically changes in the process of liver regeneration after partial hepatectomy, and gut microbiota modulation by antibiotics or probiotics affects both liver injury and regeneration. Mechanically, through the portal vein, the liver is constantly exposed to gut microbial components and metabolites, which have immense effects on the immunity and metabolism of the host. Emerging data demonstrate that gut-derived lipopolysaccharide, gut microbiota-associated bile acids, and other bacterial metabolites, such as short-chain fatty acids and tryptophan metabolites, may play multifaceted roles in liver injury and regeneration. In this perspective, we provide an overview of the possible molecular mechanisms by which gut microbiota-derived signals modulate liver injury and regeneration, highlighting the potential roles of gut microbiota in the development of gut microbiota-based therapies to alleviate liver injury and promote liver regeneration.

scholarly journals Interplay Between Exercise and Gut Microbiome in the Context of Human Health and Performance

2021 ◽  
Vol 8 ◽  
Author(s):  
Matthieu Clauss ◽  
Philippe Gérard ◽  
Alexis Mosca ◽  
Marion Leclerc
Keyword(s):  
Gut Microbiota ◽  
Bacterial Species ◽  
Integrated Approach ◽  
Short Chain Fatty Acids ◽  
Microbiota Composition ◽  
Intense Exercise ◽  
Positive Effects ◽  
Bidirectional Relationship ◽  
And Performance ◽  
Gut Microbiota Composition

Gut microbiota and exercise have recently been shown to be interconnected. Both moderate and intense exercise are typically part of the training regimen of endurance athletes, but they exert different effects on health. Moderate exercise has positive effects on the health of average athletes, such as a reduction in inflammation and intestinal permeability and an improvement in body composition. It also induces positive changes in the gut microbiota composition and in the microbial metabolites produced in the gastrointestinal tract. Conversely, intense exercise can increase gastrointestinal epithelial wall permeability and diminish gut mucus thickness, potentially enabling pathogens to enter the bloodstream. This, in turn, may contribute to the increase in inflammation levels. However, elite athletes seem to have a higher gut microbial diversity, shifted toward bacterial species involved in amino acid biosynthesis and carbohydrate/fiber metabolism, consequently producing key metabolites such as short-chain fatty acids. Moreover, rodent studies have highlighted a bidirectional relationship, with exercise impacting the gut microbiota composition while the microbiota may influence performance. The present review focuses on gut microbiota and endurance sports and how this interconnection depends upon exercise intensity and training. After pointing out the limits of the studies so far available, we suggest that taking into account the microbiota composition and its metabolic contribution to human host health could help in monitoring and modulating athletes' health and performance. Such an integrated approach should help in the design of microbiome-based solutions for health or performance.

scholarly journals Intestinal Inflammation in Children with Cystic Fibrosis Is Associated with Crohn’s-Like Microbiota Disturbances

2019 ◽  
Vol 8 (5) ◽  
pp. 645 ◽  
Author(s):  
Raphaël Enaud ◽  
Katarzyna B. Hooks ◽  
Aurélien Barre ◽  
Thomas Barnetche ◽  
Christophe Hubert ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Gut Microbiota ◽  
Intestinal Inflammation ◽  
Fecal Calprotectin ◽  
Fecal Microbiota ◽  
Bifidobacterium Adolescentis ◽  
Microbial Dysbiosis ◽  
First Time ◽  
Gut Microbiota Composition

Cystic fibrosis (CF) is a systemic genetic disease that leads to pulmonary and digestive disorders. In the majority of CF patients, the intestine is the site of chronic inflammation and microbiota disturbances. The link between gut inflammation and microbiota dysbiosis is still poorly understood. The main objective of this study was to assess gut microbiota composition in CF children depending on their intestinal inflammation. We collected fecal samples from 20 children with CF. Fecal calprotectin levels were measured and fecal microbiota was analyzed by 16S rRNA sequencing. We observed intestinal inflammation was associated with microbiota disturbances characterized mainly by increased abundances of Staphylococcus, Streptococcus, and Veillonella dispar, along with decreased abundances of Bacteroides, Bifidobacterium adolescentis, and Faecalibacterium prausnitzii. Those changes exhibited similarities with that of Crohn’s disease (CD), as evidenced by the elevated CD Microbial-Dysbiosis index that we applied for the first time in CF. Furthermore, the significant over-representation of Streptococcus in children with intestinal inflammation appears to be specific to CF and raises the issue of gut–lung axis involvement. Taken together, our results provide new arguments to link gut microbiota and intestinal inflammation in CF and suggest the key role of the gut–lung axis in the CF evolution.

scholarly journals A209 ROLE OF SEROTONIN-AUTOPHAGY AXIS IN REGULATION OF EPITHELIAL CELL FUNCTION AND MICROBIOTA COMPOSITION IN GUT

2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 81-82
Author(s):  
S Haq ◽  
H Wang ◽  
J J Kim ◽  
E Y Kwon ◽  
S Banskota ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Inflammatory Cytokines ◽  
Intestinal Inflammation ◽  
Microbiota Composition ◽  
Ec Cells ◽  
Mucosal Scraping ◽  
Ht 29 ◽  
Gut Microbiota Composition ◽  
Pro Inflammatory Cytokines

Abstract Background Serotonin (5-hydroxytryptamine; 5-HT), an enteric signalling molecule mainly produced by the enterochromaffin (EC) cells of the intestinal epithelium regulates various processes of the gut. Tryptophan hydroxylase 1 (Tph1) is the rate-limiting enzyme of 5-HT biosynthesis in EC cells. In inflammatory bowel disease (IBD) and experimental colitis, there are alterations in 5-HT content and microbiota composition in the gut. Previously we reported, Tph1-deficient (Tph1-/-) mice with reduced 5-HT in the gut exhibit reduced susceptibility to colitis. The mechanism by which 5-HT regulates colitis is unknown. Autophagy, a catabolic process regulates the function of intestinal epithelial cells (IECs), gut microbiota, and protects against intestinal inflammation. Both aberrant 5-HT signalling and autophagy is implicated in colitis. It is unclear whether they interact in regulation of production of pro-inflammatory cytokines from IECs and gut microbiota composition in relation to colitis. Our hypothesis is, an increase in 5-HT signalling inhibits autophagy in the IECs, which results in up-regulation of colitis by increasing the production of pro-inflammatory cytokines, and by selection for a more colitogenic microbiota. Aims To define the role of 5-HT-autophagy axis in the production of pro-inflammatory cytokines from IECs and gut microbiota composition in intestinal inflammation. Methods We investigated level of autophagy with or without 5% dextran sodium sulphate (DSS) in colons, mucosal scraping and IECs of Tph1-/- and their wild-type (WT) littermates. In addition, autophagy and proinflammatory cytokine production were investigated in human colonic epithelial cells (HT-29) following stimulation by 5-HT. We evaluated colitis and gut microbiota composition in WT, Tph1-/-, epithelial-specific autophagy gene Atg7 deficient (Atg7ΔIEC), and Atg7ΔIECTph1-/- (double knock out; DKO) mice. Results Tph1 -/- mice, with less 5-HT in the gut than WT mice following DSS administration exhibited an up-regulation of autophagy markers in the colon, mucosal scraping and IECs along with reduction of colitis severity. 5-HT treatment of HT-29 cells resulted in down-regulation of autophagy and upregulation of pro-inflammatory cytokine, IL-8. DKO mice exhibited increased severity of DSS-colitis, and altered microbiota composition compared to Tph1-/- mice. Conclusions These findings suggest, an increase in 5-HT in colitis inhibits autophagy in the IECs that contribute to alteration of the gut microbiota and disease severity. Blocking 5-HT signalling may promote autophagy in the IECs and alleviate the severity of colitis. Understanding the contribution of 5-HT in autophagy may identify new therapeutic target in IBD and other intestinal inflammatory conditions that exhibit dysregulated autophagy. Funding Agencies CAG, CIHR

scholarly journals Children Developing Celiac Disease Have a Distinct and Proinflammatory Gut Microbiota in the First 5 Years of Life

2020 ◽  
Author(s):  
Qian Huang ◽  
Yi Yang ◽  
Vladimir Tolstikov ◽  
Michael A. Kiebish ◽  
Jonas F Ludvigsson ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Gut Microbiota ◽  
Intestinal Inflammation ◽  
Plasma Metabolites ◽  
List Type ◽  
Healthy Controls ◽  
Microbiota Composition ◽  
Immune Mediated ◽  
Gut Microbiota Composition

ABSTRACTObjectiveCeliac disease (CD) is an immune-mediated disease characterized by small intestinal inflammation. CD is associated with HLA-DQ2 and HLA-DQ8 haplotypes, however, genetics alone cannot explain the increasing incidence rates. The main goal of this study was to determine the role of the gut microbiota in CD pathogenesis in the first five years of life.DesignWe conducted a longitudinal study focusing on three developmental phases of the gut microbiota (ages 1, 2.5 and 5 years). The fecal samples were obtained from 16 children who developed CD and 16 matched controls. We used 16S sequencing combined with functional analysis, flow cytometry, immunoglobulin A (IgA) sequencing (IgA-seq), and plasma metabolomics to determine a microbial link to CD pathogenesis.ResultsWe identified a distinct gut microbiota composition in CD progressors (CDP, children who developed CD during or after their gut microbiota were sampled) in each developmental phase. Pathogenesis and inflammation-related microbial pathways were enriched in CDP. Moreover, they had significantly more IgA coated bacteria and the IgA targets were significantly different compared to controls. Proinflammatory and pathogenesis-related metabolic pathways were enriched in CDP. Further, we identified inflammatory metabolites, particularly microbiota-derived taurodeoxycholic acid (TDCA) as increased in CDP.ConclusionOur study defines an inflammatory gut microbiota for the CDP including its composition, function, IgA response and related plasma metabolites. The inflammatory nature of CD gut microbiota during development is potentially related to the onset of the disease. Targeting inflammatory bacteria in this critical window could affect the pathogenesis and prognosis of CD.Significance of this studyWhat is already known on this subject?Celiac Disease (CD) is a gluten induced immune-mediated disease in genetically predisposed individuals.CD incidence is increasing worldwide which genetics alone cannot explain. Previous studies have shown that the gut microbiota of CD patients differ from that of healthy populations. However, the role of the microbiome in CD pathogenesis and its role in chronic inflammation is yet be established.What are the new findings?In a prospective longitudinal study in children using samples representing all three phases of gut microbiota development (ages 1, 2.5 and 5), we identified significant differences in the composition and function of gut microbiota at each phase. Pathogenesis and inflammation-related functions are enriched in the gut microbiome of CD progressors.We applied IgA-sequencing to identify inflammatory bacteria in both healthy subjects and CD progressors. Flow Cytometry analysis identified more IgA coated bacteria at ages 1 and 5 in CD progressors, indicating an early inflammatory response. CD bacterial IgA targets also differed significantly from healthy controls.We analyzed plasma metabolites obtained at age 5. The CD plasma metabolome was significantly different from healthy controls. Particularly, proinflammatory plasma metabolites, including microbiota-derived taurodeoxycholic acid (TDCA) and isobutyryl-L-carnitine, were increased two-fold in CD progressors.How might it impact clinical practice in the foreseeable future?Our results establish a link between gut microbiota composition and chronic inflammation in CD during child development. The highly IgA-coated bacteria identified in IgA sequencing and inflammatory bacteria potentially contribute to CD pathogenesis. Targeting these bacteria in the early stages of CD development could be a preventative tool.TDCA is a microbiota-derived proinflammatory metabolite increased two-fold in CD progressors. Increased TDCA levels may be used as a predictive/diagnostic tool in genetically predisposed subjects. Moreover, targeting TDCA-producing bacteria (e.g., Clostridium XIVa species) could potentially help to control the intestinal inflammation in CD.Developing anti-inflammatory probiotics/prebiotics might be viable therapeutics for altering microbiota composition in children genetically predisposed for CD. These microbes/compounds may also complement a gluten-free diet in patients that continue to experience persistent CD symptoms.

scholarly journals Dietary κ-carrageenan facilitates gut microbiota-mediated intestinal inflammation

2020 ◽  
Author(s):  
Wei Wu ◽  
Jiawei Zhou ◽  
Juanjuan Chen ◽  
Hui Han ◽  
Jingwangwei Liu ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Intestinal Inflammation ◽  
Bifidobacterium Longum ◽  
Short Chain Fatty Acids ◽  
Mucosal Damage ◽  
Microbiota Composition ◽  
Mucus Layer ◽  
Fecal Transplantation ◽  
Germ Free ◽  
Gut Microbiota Composition

Abstract Background: After nearly half a century, the inflammatory effects of carrageenan (CGN), a ubiquitous food additive, remain controversial. Little is known about its impact on the gut microbiota and intestinal homeostasis.Results: Mice fed κ-CGN showed no significant inflammatory symptoms, but showed altered colonic microbiota composition, thereby decreasing bacteria-derived short-chain fatty acids (SCFAs) and increased penetrability of the mucus layer. In mice administered the pathogenic bacterium Citrobacter rodentium, inflammation and mucosal damage were further aggravated in the presence of κ-CGN. Mucus layer defects and altered SCFA levels could be reproduced by fecal transplantation from κ-CGN-fed mice, but not from germ-free κ-CGN-fed mice. These symptoms could be partially repaired by administering the probiotics Bifidobacterium longum NCC-2705 and Faecalibacterium prausnitzii.Conclusions: We report a novel evidence that κ-CGN may not be directly inflammatory, but creates an environment that favors inflammation by perturbation of gut microbiota composition and then facilitates expansion of pathogens, which may be partially reversed by the introduction of probiotics.

scholarly journals The Role of Short-Chain Fatty Acids in Mediating Very Low-Calorie Ketogenic Diet-Infant Gut Microbiota Relationships and Its Therapeutic Potential in Obesity

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3702
Author(s):  
Naser A. Alsharairi
Keyword(s):  
Gut Microbiota ◽  
Ketogenic Diet ◽  
Therapeutic Potential ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Protective Effects ◽  
Low Calorie ◽  
Pregnancy And Lactation ◽  
Gut Microbiota Composition

As the very low-calorie ketogenic diet (VLCKD) gains increased interest as a therapeutic approach for many diseases, little is known about its therapeutic use in childhood obesity. Indeed, the role of VLCKD during pregnancy and lactation in influencing short chain fatty acid (SCFA)-producing bacteria and the potential mechanisms involved in the protective effects on obesity are still unclear. Infants are characterized by a diverse gut microbiota composition with higher abundance of SCFA-producing bacteria. Maternal VLCKD during pregnancy and lactation stimulates the growth of diverse species of SCFA-producing bacteria, which may induce epigenetic changes in infant obese gene expression and modulate adipose tissue inflammation in obesity. Therefore, this review aims to determine the mechanistic role of SCFAs in mediating VLCKD-infant gut microbiota relationships and its protective effects on obesity.

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