Project description:Background: Alcohol misuse, binge drinking pattern, and gender-specific effects in the middle-aged population has been clearly underestimated. In the present study, we focused on understanding gender-specific effects of alcohol exposure on the gut-liver axis and the role of gut microbiota in modulating gender-specific responses to alcohol consumption. Methods: Fifty-two-week-old female and male C57BL/6 mice were fasted for 12 h, and then administered a single oral dose of ethanol (EtOH) (6 g/kg). Controls were given a single dose of PBS. Animals were sacrificed 8 h later. Alternatively, fecal microbiota transplantation (FMT) was performed in 52-week-old male mice from female donors of the same age. Permeability of the large intestine (colon), gut microbiota, liver injury, and inflammation was thoroughly evaluated in all groups. Results: Middle-aged male mice exposed to EtOH showed a significant increase in gut permeability in the large intestine, evaluated by FITC-dextran assay and ZO-1, OCCLUDIN and MUCIN-2 immuno-staining, compared to PBS-treated animals, whilst female mice of the same age also increased their gut permeability, but displayed a partially maintained intestinal barrier integrity. Moreover, there was a significant up-regulation of TLRs and markers of hepatocellular injury, cell death (AST, TUNEL-positive cells) and lipid accumulation (ORO) in male mice after EtOH exposure. Interestingly, FMT from female donors to male mice reduced gut leakiness, modified gut microbiota composition, ameliorated liver injury and inflammation, TLR activation and the senescence phenotype of middle-aged mice. Conclusion: Our findings highlighted the relevance of gender in middle-aged individuals who are exposed to alcohol in the gut-liver axis. Moreover, our study revealed that gender-specific microbiota transplantation might be a plausible therapy in the management of alcohol-related disorders during aging.
Project description:Alcohol is among the most widely consumed dietary substances. While excessive alcohol consumption damages the liver, heart and brain, clinical observations also suggest that alcohol has strong immunoregulatory properties. However, little is known about the mechanistic effects of alcohol on the immune system. T cell functions such as migration, immune synapse formation and activation depend on the reorganization of the cytoskeleton. In this study, we show that acetate, the metabolite of alcohol, effectively inhibits the migratory capacity of T cells through increased tissue acetate levels that lead to acetylation of cortactin, a protein that binds filamentous actin and facilitates branching. Current knowledge of cortactin’s role in T cells is limited. Here we demonstrate and confirm that primary mouse and human T cells express cortactin and acetylation of cortactin inhibits actin filament binding leading to reduced filament branching, lamellipodia formation and T cell migration. Mutated acetylation-resistant cortactin rescued the acetate-induced inhibition of T cell migration. Primary mouse cortactin knock-out T cells exhibited severely reduced T cell migration. Furthermore, acetate-induced cytoskeletal changes effectively inhibited activation, proliferation, and immune synapse formation in T cells exposed to acetate at tissue concentrations reached by alcohol consumption. In summary, these data show that acetate, the key metabolite of alcohol, is inhibiting T cell mediated immune responses by modulating the biomechanics of T cells through their cytoskeletal function.
Project description:Alcohol is among the most widely consumed dietary substances. While excessive alcohol consumption damages the liver, heart and brain, clinical observations also suggest that alcohol has strong immunoregulatory properties. However, little is known about the mechanistic effects of alcohol on the immune system. In this context, we investigated the effect of acetate, the metabolite of alcohol, on primary mouse T cells, unspecifically activated with dynabeads.
Project description:The mammalian gastrointestinal tract contains a diverse ecosystem of microbial species collectively making up the gut microbiome. Emerging evidence highlights a critical relationship between gut microbiota and neurocognitive development. Consumption of unhealthy yet palatable dietary factors associated with obesity and metabolic dysfunction (e.g., saturated fat, added sugar) produces microbiota dysbiosis and negatively impacts neurocognitive function, particularly when consumed during early life developmental periods. Here we explore whether excessive early life consumption of added sugars negatively impacts neurocognitive development via the gut microbiome. Using a rodent model of habitual sugar-sweetened beverage (SSB) consumption during the adolescent stage of development, we first show that excessive early life sugar intake impairs hippocampal-dependent memory function when tested during adulthood while preserving other neurocognitive domains. Gut microbiome genomic sequencing analyses reveal that early life SSB consumption alters the abundance of various bacterial populations, including elevations in operational taxonomic units within the genus Parabacteroides (P. distasonis and P. johnsonii) whose abundance negatively correlated with memory task performance. Additional results reveal that in vivo Parabacteroides enrichment of cultured P. distasonis and P. johnsonii bacterial species in adolescent rats severely impairs memory function during adulthood. Hippocampus transcriptome analyses identify gene expression alterations in neurotransmitter synaptic signaling, intracellular kinase signaling, metabolic function, neurodegenerative disease, and dopaminergic synaptic signaling-associated pathways as potential mechanisms linking microbiome outcomes with memory impairment. Collectively these results identify microbiota dysbiosis as a mechanism through which early life unhealthy dietary patterns negatively impact neurocognitive outcomes.
Project description:The etiology of alcohol dependence is not completely understood. Increasing evidence reveals that gut microbiota dysbiosis is associated with certain psychiatric disorders, including alcoholism, through the 'microbiota-gut-brain' axis. The aims were to evaluate the effect of alcohol abuse on the gut microbiota, intestinal permeability and serum metabolic profile and to determine whether alcohol-induced alterations in gut microbiota are correlated with gut permeability and serum metabolic phenotype changes. 16S rRNA gene high-throughput sequencing and nontarget metabolomics techniques were applied in an alcohol-dependent rat model in the present study. The results showed that alcohol intake altered the composition and structure of the colonic microbiota, especially the relative abundance of the commensal microbes <i>Lachnospiraceae</i> and <i>Prevotellaceae</i>, which was significantly decreased. Alcohol-dependent rats developed gut leakiness and a serum metabolic phenotype disorder. The valine, leucine and isoleucine biosynthesis pathways and arginine and proline metabolism pathways were obviously influenced by alcohol intake. Moreover, alcohol consumption disturbed the brain's neurotransmitter homeostasis. The regression analysis showed that alcohol-induced colonic microbiota dysbiosis was strongly associated with increased intestinal permeability and serum metabolic phenotype and neurotransmitter disorders. These results revealed that gut microbiota dysbiosis and serum metabolites alteration might be a cofactor for developing of alcohol dependence. <b>IMPORTANCE</b> The gut microbiota dysbiosis is associated with certain psychiatric disorders through the 'microbiota-gut-brain' axis. Here we revealed that alcohol consumption induced the colonic microbiota dysbiosis, increased intestinal permeability, altered the serum metabolic phenotype in rats, and there were a strong correlation between gut microbiota dysbiosis and serum metabolites disorders. Thus, gut microbiota dysbiosis and serum metabolites alteration may be a cofactor for development of alcohol dependence.
Project description:Background and Aims: Many inflammatory diseases are associated with microbial dysbiosis, which may considerably alter the production of short-chain fatty acids (SCFAs). SCFAs are produced in the large bowel through bacterial fermentation of dietary fiber and play an important role in maintaining gut homeostasis. SCFAs, particularly acetate and butyrate, show beneficial immunomodulatory effects contributing to the prevention of inflammatory and allergic reactions. Thus, reduced production of SCFAs may impact on the mucosal immune responses critical to fighting pathogens. This study aims to determine the influence of SCFAs on a murine model of colonic bacterial infection. Methods: In the present study, we used acetate- (HAMSA) or butyrate- (HAMSB) yielding diets to deliver high concentrations of individual SCFAs to the large bowel of mice infected with C. rodentium. We assessed the effects of these SCFAs on clinical burden and gut pathogenicity in correlation with changes in bacteria growth, fecal microbiota composition, function and changes in the immunological profile. Results: Here we show in vitro that acetate and butyrate directly inhibited growth of the attaching and effacing (A/E) pathogen C. rodentium in a bacteriostatic manner. This correlated with reduced expression of Tir, a gene responsible for bacterial adherence and pathogenicity. Interestingly, HAMSA-fed mice presented reduced clinical scores during C. rodentium infection associated with high concentrations of fecal acetate. This was linked with compositional and functional changes in the microbiota when examining 16s sequencing and proteomics analysis. The HAMSA mediated is protection involved increased expression IL-22 and Muc-2 in the colon and increased numbers of CD8αα+ TCRγδ T cells in the colonic epithelium. These effects were dependent on GPR43, a metabolite-sensing GPCR that binds acetate. Conclusions: We established a promising new approach to moderate bacterial gut infections by manipulating the gut microbiota and mucosal immune tolerance through diets that yield the SCFA acetate.
Project description:Understanding how the human gut microbiota and host are impacted by probiotic bacterial strains requires carefully controlled studies in humans, and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks prior to, 7 weeks during, and 4 weeks following consumption of a commercially-available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied prior to and after gavage with all five sequenced FMP strains. 140 samples total. Evaluation of changes in a model community's structure over time after exposure to a consortium of 5 fermented milk product (FMP) strains.
Project description:<h4><strong>BACKGROUND:</strong></h4><p>Gut microbiota profiles are closely related to cardiovascular diseases through mechanisms that include the reported deleterious effects of metabolites, such as trimethylamine N-oxide (TMAO), which have been studied as diagnostic and therapeutic targets. Moderate red wine (RW) consumption is reportedly cardioprotective, possibly by affecting the gut microbiota.</p><h4><strong>OBJECTIVES:</strong></h4><p>To investigate the effects of RW consumption on the gut microbiota, plasma TMAO, and the plasma metabolome in men with documented coronary artery disease (CAD) using a multiomics assessment in a crossover trial.</p><h4><strong>METHODS:</strong></h4><p>We conducted a randomized, crossover, controlled trial involving 42 men (average age, 60 y) with documented CAD comparing 3-wk RW consumption (250 mL/d, 5 d/wk) with an equal period of alcohol abstention, both preceded by a 2-wk washout period. The gut microbiota was analyzed via 16S rRNA high-throughput sequencing. Plasma TMAO was evaluated by LC-MS/MS. The plasma metabolome of 20 randomly selected participants was evaluated by ultra-high-performance LC-MS/MS. The effect of RW consumption was assessed by individual comparisons using paired tests during the abstention and RW periods.</p><h4><strong>RESULTS:</strong></h4><p>Plasma TMAO did not differ between RW intervention and alcohol abstention, and TMAO concentrations showed low intraindividual concordance over time, with an intraclass correlation coefficient of 0.049 during the control period. After RW consumption, there was significant remodeling of the gut microbiota, with a difference in β diversity and predominance of Parasutterella, Ruminococcaceae, several Bacteroides species, and Prevotella. Plasma metabolomic analysis revealed significant changes in metabolites after RW consumption, consistent with improved redox homeostasis.</p><h4><strong>CONCLUSIONS:</strong></h4><p>Modulation of the gut microbiota may contribute to the putative cardiovascular benefits of moderate RW consumption. The low intraindividual concordance of TMAO presents challenges regarding its role as a cardiovascular risk biomarker at the individual level. This study was registered at clinical trials.gov as NCT03232099.</p>
Project description:Understanding how the human gut microbiota and host are impacted by probiotic bacterial strains requires carefully controlled studies in humans, and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks prior to, 7 weeks during, and 4 weeks following consumption of a commercially-available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied prior to and after gavage with all five sequenced FMP strains. 73 samples total. Evaluation of changes in a model community's metatranscriptome over time after exposure to a consortium of 5 fermented milk product (FMP) strains (40 samples); evaluation of the gene expression of the FMP strains in other in vitro conditions, including MRS medium (B. animalis subsp. lactis only, 4 samples) and a commercial FMP fermentation (all 5 strains, 6 samples); evaluation of the gene expression of native human microbiomes before and after the consumption of a commercial FMP (23 samples).