Project description:Age-dependent changes of the gut-associated microbiome have been linked to increased frailty and systemic inflammation. This study found that age-associated changes of the gut microbiome of BALB/c and C57BL/6 mice could be reverted by co-housing of aged (22 months old) and adult (3 months old) mice for 30-40 days or faecal microbiota transplantation (FMT) from adult into aged mice. This was demonstrated using high-throughput sequencing of the V3-V4 hypervariable region of bacterial 16S rRNA gene isolated from faecal pellets collected from 3-4 months old adult and 22-23 months old aged mice before and after co-housing or FMT.
Project description:Gut microbial β-glucuronidase (GUS) enzymes play important roles in drug efficacy and toxicity, intestinal carcinogenesis, and mammalian-microbial symbiosis. Recently, the first catalog of human gut GUS proteins was provided for the Human Microbiome Project stool sample database and revealed 279 unique GUS enzymes organized into six categories based on active-site structural features. Because mice represent a model biomedical research organism, here we provide an analogous catalog of mouse intestinal microbial GUS proteins-a mouse gut GUSome. Using metagenome analysis guided by protein structure, we examined 2.5 million unique proteins from a comprehensive mouse gut metagenome created from several mouse strains, providers, housing conditions, and diets. We identified 444 unique GUS proteins and organized them into six categories based on active-site features, similarly to the human GUSome analysis. GUS enzymes were encoded by the major gut microbial phyla, including Firmicutes (60%) and Bacteroidetes (21%), and there were nearly 20% for which taxonomy could not be assigned. No differences in gut microbial gus gene composition were observed for mice based on sex. However, mice exhibited gus differences based on active-site features associated with provider, location, strain, and diet. Furthermore, diet yielded the largest differences in gus composition. Biochemical analysis of two low-fat-associated GUS enzymes revealed that they are variable with respect to their efficacy of processing both sulfated and nonsulfated heparan nonasaccharides containing terminal glucuronides.IMPORTANCE Mice are commonly employed as model organisms of mammalian disease; as such, our understanding of the compositions of their gut microbiomes is critical to appreciating how the mouse and human gastrointestinal tracts mirror one another. GUS enzymes, with importance in normal physiology and disease, are an attractive set of proteins to use for such analyses. Here we show that while the specific GUS enzymes differ at the sequence level, a core GUSome functionality appears conserved between mouse and human gastrointestinal bacteria. Mouse strain, provider, housing location, and diet exhibit distinct GUSomes and gus gene compositions, but sex seems not to affect the GUSome. These data provide a basis for understanding the gut microbial GUS enzymes present in commonly used laboratory mice. Further, they demonstrate the utility of metagenome analysis guided by protein structure to provide specific sets of functionally related proteins from whole-genome metagenome sequencing data.
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 performed a phase I clinical trial to assess the safety and feasibility of fecal microbiota transplantation (FMT) and re-induction of anti-PD-1 immunotherapy in patients with anti-PD-1-refractory metastatic melanoma. FMT donors were two metastatic melanoma patients who achieved a durable complete response. FMT recipient patients were metastatic melanoma patients who failed at least one anti-PD-1 line of treatment. Each recipient patient received FMT implants from only one of the two donors. FMT was conducted by both colonoscopy and oral ingestion of stool capsules, followed by anti-PD-1 re-treatment (Nivolumab, BMS). Recipient patients underwent pre- and post-treatment stool sampling, tissue biopsy of both gut and tumor, and total body imaging. Clinical responses were observed in three patients, including two partial responses and one complete response. Notably, treatment with FMT was associated with favorable changes in immune cell infiltrates and gene expression profiles in both the gut lamina propria and the tumor microenvironment.
Project description:Parkinson's disease (PD) is a common neurodegenerative disease in middle-aged and elderly people. The disorder of gut microbiota is involved in the pathophysiological process of various neurological diseases, and many studies have confirmed that gut microbiota is involved in the progression of PD. As one of the most effective methods to reconstruct gut microbiota, fecal microbiota transplantation (FMT) has been considered as an important treatment for PD. However, the mechanism of FMT treatment for PD is still lacking, which requires further exploration and can facilitate the application of FMT. As a model organism, Drosophila is highly conserved with mammalian system in maintaining intestinal homeostasis. In this study, there were significant differences in the gut microbiota of conventional Drosophila colonized from PD patients compared to those transplanted from normal controls. And we constructed rotenone-induced PD model in Drosophila followed by FMT in different groups, and investigated the impact of gut microbiome on transcriptome of the PD host. Microbial analysis by 16S rDNA sequencing showed that gut microbiota could affect bacterial structure of PD, which was confirmed by bacterial colonization results. In addition, transcriptome data suggested that gut microbiota can influence gene expression pattern of PD. Further experimental validations confirmed that lysosome and neuroactive ligand-receptor interaction are the most significantly influenced functional pathways by PD-derived gut microbiota. In summary, our data reveals the influence of PD-derived gut microbiota on host transcriptome and helps better understanding the interaction between gut microbiota and PD through gut-brain axis. The present study will facilitate the understanding of the mechanism underlying PD treatment with FMT in clinical practice.