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 explore whether a low-energy diet intervention for Metabolic dysfunction-associated steatohepatitis (MASH) improves liver disease by means of modulating the gut microbiome. 16 individuals were given a low-energy diet (880 kcal, consisting of bars, soups, and shakes) for 12 weeks, followed by a stepped re-introduction to whole for an additional 12 weeks. Stool samples were obtained at 0, 12, and 24 weeks for microbiome analysis. Fecal microbiome were measured using 16S rRNA gene sequencing. Positive control (Zymo DNA standard D6305) and negative control (PBS extraction) were included in the sequencing. We found that low-energy diet improved MASH disease without lasting alterations to the gut microbiome.
Project description:Many ancient parchments are defaced by red or purple maculae associated with localized destruction of collagen fibres. Although the main characteristics of this damage were present in most of the manuscripts analysed by many authors, no common microbial or fungal denominator has been found so far, and little or no correspondence between the microbial or fungal species isolated from materials could be addressed. In this study, culture-independent molecular methods and scanning electron microscopy (SEM) were used to identify fungal and bacterial communities on parchments affected by the purple stains. Protocols for c extraction and nucleic-acid-based strategies were selected for assays examining the community structure of fungi and bacteria on biodeteriorated parchment. Both SEM and molecular analysis detected the presence of bacterial and fungal cells in the damaged areas. Halophilic, halotolerant proteolytic bacterial species were selected by the saline environment provided by the parchment samples. As common microbial denominators, members of the Actinobacteria, mainly Saccharopolyspora spp. and species of Aspergillus, were detected in all investigated cases. It is proposed that a relationship exists between the phenomenon of purple spots on ancient parchments and that of the 'red heat' phenomenon, known to be present in some products manufactured with marine salt.