Family structure influences the gut microbiota of the Sino-Mongolian beaver (Castor fiber birulai) rather than age and gender

Gut microbiota is crucial for the health and survival of wildlife. In this study, metagenomic analysis was performed on fecal samples of endangered Sino-Mongolian beavers (Castor fiber birulai) from three groups rescued in the wild, to explore the potential factors affecting the gut microbiota of the Sino-Mongolian beaver. The results revealed that family structure is the primary factor influencing the gut microbiota of beavers (R = 0.897, P = 0.015), rather than age (R = 0.2, P = 0.135) and gender (R = −0.118, P = 0.692). This may be due to the obligate monogamy and strict family-based social structure of beavers. Meanwhile, the non-family group (solitary or couple) exhibited significantly unhealthy gut microbial composition and higher disease risk compared to the family group (parents with their offspring). Among the pathways that were significantly more abundant in non-family groups, 71 % (5 out of 7) were associated with diseases. This suggests that ensuring the family formation and size of the Sino-Mongolian beaver could maintain their homeostasis and healthy survival status, thereby better protecting this endangered subspecies.