Grazing Is Associated With Dietary Diversity and Gastrointestinal Microbiota in Subterranean Rodents

Diet significantly influences gut microbiota composition. Grazing activities alter local vegetation communities, which in turn are related to changes in the availability of food resources for wildlife. However, the relationships between grazing and the dietary diversity and gut microbiota in subterranean rodents remain poorly understood. Using the plateau zokor (Eospalax baileyi) as a model species, chloroplast trnL and 16S rRNA gene sequencing were employed to characterize dietary composition and gastrointestinal microbial communities in zokors from grazing and non-grazing (control) areas. The analysis revealed significant differences in dietary diversity and composition of zokors between grazing and non-grazing areas. Meanwhile, the gastrointestinal microbial community diversity differed significantly between groups. Beneficial microbes (e.g., Lachnospiraceae and Christensenellaceae) showed higher abundance in the control group, while pathogenic Proteobacteria were enriched in the grazing groups. Notably, the complexity of stomach microbial co-occurrence networks increased in the grazing group, and functional differentiation of the gastrointestinal microbiota was observed between the control and grazing groups. Community assembly analysis displayed that stochastic processes dominated the assembly of stomach and gut microbiota, though these processes diminished in the grazing group, where divergent ecological processes emerged. Furthermore, we identified robust associations between zokor diets and stomach/gut microbiota, with specific microbial taxa significantly correlated with particular plants. Collectively, these findings highlight that grazing is associated with dietary changes and gut microbiota shifts in subterranean rodents, thereby advancing our understanding of the ecological impacts of grazing on terrestrial ecosystems.