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Viciani, E.

Publications and source records attributed to Viciani, E..

2 recordsLinked to original sources

Functional and taxonomic comparison of mouse and human gut microbiotas using extensive culturing and metagenomics

Mouse models are essential for biomedical science and drug discovery, yet it is not known how the bacteria in the mouse microbiota - important determinants of phenotypes of health and disease -affect their relevance to human disease. To interrogate the taxonomic and functional differences between the human and mouse gut microbiotas, we developed the Mouse Microbial Genome Collection (MMGC), a compilation of 276 genomes from cultured isolates and 45,218 metagenome-assembled genomes (MAGs) from 1,960 publicly available mouse metagenomes. The MMGC reveals that while only 2.65% of bacterial species are shared between mouse and human, over 80% of annotatable functions are present in both microbiomes. Using drug metabolism and butyrate synthesis as examples, we illustrate that although the species harbouring these key functions can differ between hosts, the MMGC enables identification of functionally equivalent taxa in the mouse and human microbiotas. The MMGC thereby facilitates the informed use of mice in biomedical research by providing access to the conservation and taxonomic locations of bacterial functions of interest.

microbiology

Host adaptation in gut Firmicutes is associated with sporulation loss and altered colonisation patterns

Human-to-human transmission of symbiotic, anaerobic bacteria is a fundamental evolutionary adaptation essential for membership of the human gut microbiota. However, despite its importance, the genomic and biological adaptations underpinning symbiont transmission remain poorly understood. Here, we show that sporulation ability, which promotes transmission of anaerobic bacteria, has been independently lost in many distinct evolutionary lineages of gut bacteria belonging to the Firmicutes phyla. Analysis of 1358 genome-sequenced Firmicutes reveals loss of sporulation is associated with features of host-adaptation such as genome reduction and specialized metabolic capabilities. Consistent with these data, analysis of 28,000 gut metagenomes from people around the world demonstrates that bacteria now incapable of sporulation are more abundant but less prevalent in the human population compared to spore-forming bacteria. Our results suggest host adaptation in gut Firmicutes is an evolutionary trade-off between transmission range and colonisation abundance, leading to distinct transmission cycles. We reveal host transmission as an underappreciated process that shapes the evolution, assembly and functions of gut Firmicutes.

microbiology