Gut microbiota and host divergence times

The gut microbiota of animals plays a key role in host evolution. However, the possible relationship between gut microbiota and host divergence time remains unknown. Here, we investigated the gut microbiota of eight Glires species (four lagomorpha species and four rodent species) distributed throughout the Qinghai-Tibet plateau and Inner Mongolia grassland. Lagomorphs and rodents had distinct gut microbial composition. Three out of four lagomorpha species were dominated by Firmicutes, while rodents were predominated by Bacteroidetes in general. The alpha diversity values (Shannon diversity and evenness) exhibited significant differences between any two species within lagomorphs, whereas there were no significant differences among rodents. The structure of gut microbiota between lagomorphs and rodents showed significant differences. In addition, we calculated host phylogeny and divergence times, and used a phylogenetic approach to reconstruct how the animal gut microbiota has diverged from their ancestral species. Some important functional bacteria (e.g. Prevotella and Clostridium) showed marked changes within lagomorphs. The weighted uniFrac and Bray-Curtis dissimilarity of Glires gut microbiota were positively correlated with host divergence time. Our results demonstrated the co-evolution relationship between the gut microbiota and hosts. It suggests that dissimilarity of animal gut microbiota may predict host divergence time.