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:Host-microbiome-dietary interactions play crucial roles in regulating human health, yet direct functional assessment of their interplays, cross-regulations and downstream disease impacts remains challenging. We adopted metagenome-informed metaproteomics (MIM), in both mice and humans, to simultaneously explore host, dietary, and species-level microbiome interactions across diverse scenarios, including commensal and pathogen colonization, nutritional modifications, and antibiotic-induced perturbations. Implementation of MIM in murine auto-inflammation and in human IBD characterized a ‘compositional dysbiosis’ and a concomitant, species-specific ‘functional dysbiosis’ driven by suppressed commensal responses to inflammatory host signals. Microbiome transfers unraveled early-onset kinetics of these host-commensal cross-responsive patterns, while predictive analyses identified candidate fecal host-microbiome IBD biomarker protein pairs outperforming S100A8/S100A9 (calprotectin). Importantly, a simultaneous fecal nutrient assessment enabled determination of IBD-related consumption patterns, dietary treatment compliance and small-intestinal digestive aberrations. Collectively, a parallelized dietary-bacterial-host MIM assessment functionally uncovers trans-kingdom interactomes shaping gastrointestinal ecology, while offering personalized diagnostic and therapeutic insights into microbiome-associated disease.
Project description:Host-microbiome-dietary interactions play crucial roles in regulating human health, yet direct functional assessment of their interplays, cross-regulations and downstream disease impacts remains challenging. We adopted metagenome-informed metaproteomics (MIM), in both mice and humans, to simultaneously explore host, dietary, and species-level microbiome interactions across diverse scenarios, including commensal and pathogen colonization, nutritional modifications, and antibiotic-induced perturbations. Implementation of MIM in murine auto-inflammation and in human IBD characterized a ‘compositional dysbiosis’ and a concomitant, species-specific ‘functional dysbiosis’ driven by suppressed commensal responses to inflammatory host signals. Microbiome transfers unraveled early-onset kinetics of these host-commensal cross-responsive patterns, while predictive analyses identified candidate fecal host-microbiome IBD biomarker protein pairs outperforming S100A8/S100A9 (calprotectin). Importantly, a simultaneous fecal nutrient assessment enabled determination of IBD-related consumption patterns, dietary treatment compliance and small-intestinal digestive aberrations. Collectively, a parallelized dietary-bacterial-host MIM assessment functionally uncovers trans-kingdom interactomes shaping gastrointestinal ecology, while offering personalized diagnostic and therapeutic insights into microbiome-associated disease.
Project description:Activation of inflammatory pathways in human IBD IL-6:STAT3 pathways are activated in the affected colon in IBD. However, the functional implications of this are not known. We hypothesized that pro-inflammatory IL-6:STAT3 dependent networks would be up regulated in the colon of pediatric patients with Crohn Disease (CD) and Ulcerative Colitis (UC), and that these would regulate leukocyte survival, proliferation, and recruitment to the gut. These experiments tested differential colon gene expression relative to these pathways in healthy, CD, and UC samples. Colon biopsy samples were obtained from CD and UC patients at diagnosis, CD patients during therapy, and healthy controls. The global pattern of gene expression was determined using GeneSpring software, and biological networks were identified using Ingenuity software. Data suggested that two IL-6:STAT3 dependent networks are up regulated in pediatric IBD both at diagnosis and during therapy which regulate leukocyte recruitment and survival. The degree of up regulation of these genes compared to healthy controls was remarkably conserved across the two CD groups and the UC groups, suggesting common mechanisms of mucosal inflammation. Keywords: Single time point in CD, UC, and healthy controls.