Experimental evidence for adaptation to species-specific gut microbiota in house mice. Experimental evidence for adaptation to species-specific gut microbiota in house mice

The gut microbial communities of mammals have co-diversified with host species, and changes in the gut microbiota can have profound effects on host fitness. Therefore, the gut microbiota may drive adaptation in mammalian species, but this possibility is underexplored. Here, we show that the gut microbiota has co-diversified with mice in the genus Mus over the past ~6 million years, and we present experimental evidence that the gut microbiota has driven adaptive evolution of the house mouse, M. m. domesticus. Phylogenetic analyses of metagenome-assembled bacterial genomic sequences revealed that gut bacterial lineages have been retained within and diversified alongside Mus species over evolutionary time. Transplantation of gut microbiotas from various Mus species into germ-free M. m. domesticus showed that foreign gut microbiotas slowed growth rate and upregulated macrophage inflammatory protein in hosts. These results suggest adaptation by M. m. domesticus to its gut microbiota since diverging from other Mus species.