Diet diversity and gut microbial diversity

Mammals’ diets potentially influence the composition of symbiotic gut microbiota. Reports regarding diet-microbiota relationships generally focus on the efforts of simple nutritional ingredients or caloric intake. However, mammals often consume a diverse mixture of foods in natural environments, and each animal individual has unique diet profile and gut microbiota composition. Little is known about which factors influence the diet and gut microbiota composition, and the relationship between diet diversity and gut microbial diversity in wild mammals. Using 16S rRNA gene sequencing, we characterized the gut microbiota from 24 plateau pikas(Ochotona curzoniae) at three altitudinal sites. In addition, we performed ITS gene sequencing of the same individuals to characterize the diet of each pika. We found that altitude significantly affected the composition and structure of diet and gut microbiota, whereas animal sex and weight had no any effects in shaping the diet or gut microbiota. Notably, the alpha diversity (Shannon diversity and observed OTUs) of diet was not significantly correlated with that of gut microbiota, whereas the beta diversity (Jaccard and Bray-Curtis dissimilarity) of diet is positively correlated with that of gut microbiota. Our results suggest that diet diversity is not associated with pika gut microbiota diversity, whereas individuals that are more similar in diet harbor more similar gut microbiota.