The composition and function of pika gut microbiota

The gut mirobiota in mammals play a key role in host nutrition and health. However, little is known regarding those factors that shape variations of the gut microbiota composition and, importantly, their functions. Here, we investigated the gut microbiota, short chain fatty acid (SCFA) profile and cellulolytic activity across 111 samples from two common pika populations in China, including Plateau pikas from Qinghai-Tibet Plateau and Daurian pikas from Inner Mongolia Grassland. Similar to other small mammals, pika gut microbiota were dominated by the phyla Firmicutes, Bacteroidetes, Proteobacteria and Spirochaetes. At genus level, four predominant bacterial genera, including Prevotella, Oscillospira, Ruminococcus and Treponema were also core bacterial taxa. The gut microbial community of pikas showed higher levels of microbial biodiversity, total SCFA concentration and cellulolytic activity in summer or plateau pikas when compared to in winter or Daurian pikas. The structural segregation of pika gut microbial communities between seasons or host species was evident, and co-varied with SCFA profile and cellulolytic activity. Our results suggested that pika gut microbiota composition and function co-vary in response to seasons and host species.