Project description:Seasonal influenza outbreaks represent a large burden for the healthcare system as well as the economy. While the role of the microbiome in the context of various diseases has been elucidated, the effects on the respiratory and gastrointestinal microbiome during influenza illness is largely unknown. Therefore, this study aimed to characterize the temporal development of the respiratory and gastrointestinal microbiome of swine using a multi-omics approach prior and during influenza infection. Swine is a suitable animal model for influenza research, as it is closely related to humans and a natural host for influenza viruses. Our results showed that IAV infection resulted in significant changes in the abundance of Moraxellaceae and Pasteurellaceae families in the upper respiratory tract. To our surprise, temporal development of the respiratory microbiome was not affected. Furthermore, we observed significantly altered microbial richness and diversity in the gastrointestinal microbiome after IAV infection. In particular, we found increased abundances of Prevotellaceae, while Clostridiaceae and Lachnospiraceae decreased. Furthermore, metaproteomics showed that the functional composition of the microbiome, known to be robust and stable under healthy conditions, was heavily affected by the influenza infection. Metabolome analysis proved increased amounts of short-chain fatty acids in the gastrointestinal tract, which might be involved in faster recovery. Furthermore, metaproteome data suggest a possible immune response towards flagellated Clostridia induced during the infection. Therefore, it can be assumed that the respiratory infection with IAV caused a systemic effect in the porcine host and microbiome.
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.