Project description:Gut microbiome research is rapidly moving towards the functional characterization of the microbiota by means of shotgun meta-omics. Here, we selected a cohort of healthy subjects from an indigenous and monitored Sardinian population to analyze their gut microbiota using both shotgun metagenomics and shotgun metaproteomics. We found a considerable divergence between genetic potential and functional activity of the human healthy gut microbiota, in spite of a quite comparable taxonomic structure revealed by the two approaches. Investigation of inter-individual variability of taxonomic features revealed Bacteroides and Akkermansia as remarkably conserved and variable in abundance within the population, respectively. Firmicutes-driven butyrogenesis (mainly due to Faecalibacterium spp.) was shown to be the functional activity with the higher expression rate and the lower inter-individual variability in the study cohort, highlighting the key importance of the biosynthesis of this microbial by-product for the gut homeostasis. The taxon-specific contribution to functional activities and metabolic tasks was also examined, giving insights into the peculiar role of several gut microbiota members in carbohydrate metabolism (including polysaccharide degradation, glycan transport, glycolysis and short-chain fatty acid production). In conclusion, our results provide useful indications regarding the main functions actively exerted by the gut microbiota members of a healthy human cohort, and support metaproteomics as a valuable approach to investigate the functional role of the gut microbiota in health and disease.
Project description:We have previously demonstrated that the gut microbiota can play a role in the pathogenesis of conditions associated with exposure to environmental pollutants. It is well accepted that diets high in fermentable fibers such as inulin can beneficially modulate the gut microbiota and lessen the severity of pro-inflammatory diseases. Therefore, we aimed to test the hypothesis that hyperlipidemic mice fed a diet enriched with inulin would be protected from the pro-inflammatory toxic effects of PCB 126.
Project description:Gut microbiota comparation of Young mice (n=10), Old mice, Young_yFMT (Young mice 14 days after transplant feces from young mice, n=10) and Young_oFMT (Young mice 14 days after transplant feces from old mice, n=10), Antibiotic group (Cefazolin, n=8).
Project description:Transcriptome analysis using the liver from young versus old mice, fed either normally or under caloric restriction reveals reorganization of distinct circadian signatures related to metabolic aging and nutrient-dependent counterbalance of aging by caloric restriction
Project description:Hematopoietic stem cell (HSC) aging is accompanied by hematopoietic reconstitution dysfunction, including loss of regenerative and engraftment ability, myeloid differentiation bias and elevated risks of hematopoietic malignancies. Gut microbiota, a key regulator of host health and immunity, has been recently reported to impact hematopoiesis. However, there is currently no empirical evidence elucidating the direct impact of gut microbiome on aging hematopoiesis. To assess these potential effects, we performed fecal microbiota transplantation (FMT) from young mice to aged mice and observed an increment in both the absolute number and the engraftment ability of HSCs. Single cell RNA sequencing depicted overall transcriptional changes of HSCs as well as the bone marrow microenvironment and indicated that gut microbiota from young mice enhanced cell cycle activity of HSCs, attenuated canonical inflammatory signals and mitigated inflammation-associated phenotypes in aging hematopoiesis. Integrated microbiome-metabolome analysis uncovered that FMT reshaped gut microbiota construction and metabolite landscape, while the administration of Lachnospiraceae and tryptophan-associated metabolites promoted the recovery of hematopoiesis and rejuvenated aged HSCs. Together, our results highlighted the paramount importance of the gut microbiota in HSC aging and provided a strong rationale to limit hematopoietic exhaustion and treat hematologic disorders.
Project description:Astrocytes are key cells in brain aging, helping neurons to undertake healthy aging or otherwise letting them enter into a spiral of neurodegeneration. We aimed to characterize astrocytes cultured from senescence-accelerated prone 8 (SAMP8) mice, a mouse model of brain pathological aging, along with the effects of caloric restriction, the most effective rejuvenating treatment known so far. Analysis of the transcriptomic profiles of SAMP8 astrocytes cultured in control conditions and treated with caloric restriction serum was performed using mRNA microarrays. A decrease in mitochondrial and ribosome mRNA, which was restored by caloric restriction, confirmed the age-related profile of SAMP8 astrocytes and the benefits of caloric restriction. An amelioration of antioxidant and neurodegeneration-related path- ways confirmed the brain benefits of caloric restriction. Studies of oxidative stress and mitochondrial function demonstrated a reduction of oxidative damage and partial improvement of mito- chondria after caloric restriction. In summary, caloric restriction showed a significant tendency to normalize pathologically aged astrocytes through the activation of pathways that are protective against the age-related deterioration of brain physiology. Key words: astrocytes; caloric restriction; mitochondria; oxidative stress; RNA microarrays; SAMP8.
Project description:Gut microbiota dysbiosis characterizes systemic metabolic alteration, yet its causality is debated. To address this issue, we transplanted antibiotic-free conventional wild-type mice with either dysbiotic (“obese”) or eubiotic (“lean”) gut microbiota and fed them either a NC or a 72%HFD. We report that, on NC, obese gut microbiota transplantation reduces hepatic gluconeogenesis with decreased hepatic PEPCK activity, compared to non-transplanted mice. Of note, this phenotype is blunted in conventional NOD2KO mice. By contrast, lean microbiota transplantation did not affect hepatic gluconeogenesis. In addition, obese microbiota transplantation changed both gut microbiota and microbiome of recipient mice. Interestingly, hepatic gluconeogenesis, PEPCK and G6Pase activity were reduced even once mice transplanted with the obese gut microbiota were fed a 72%HFD, together with reduced fed glycaemia and adiposity compared to non-transplanted mice. Notably, changes in gut microbiota and microbiome induced by the transplantation were still detectable on 72%HFD. Finally, we report that obese gut microbiota transplantation may impact on hepatic metabolism and even prevent HFD-increased hepatic gluconeogenesis. Our findings may provide a new vision of gut microbiota dysbiosis, useful for a better understanding of the aetiology of metabolic diseases. all livers are from NC-fed mice only.
Project description:The mouse stool samples were collected from different diets fed mice and bacterial cells were harvest for metaproteomic analysis for understanding the role ofdiet on gut microbiota.