Seasonal patterns of the gut microbiota in the Assamese macaques (Macaca assamensis) in a limestone forest in Guangxi, China

Exploring the interaction between the gut microbiota and the host is beneficial for understanding the host’s adaptive potential and evolution. Whether Assamese macaques living in limestone habitats in Guangxi undergo cyclical shifts in their gut microbiota in the face of seasonal environmental changes, especially abundant rainfall from May to October and significantly reduced rainfall from November to April, remains unelucidated. In this study, 16S rRNA sequencing was used to analyze the gut microbiota composition of wild macaques in the limestone forest, Guangxi, and the seasonal pattern of their gut microbiota was explored using the combined data of diet composition, food availability index, and climate factors. The results indicated that Firmicutes and Proteobacteria were the dominant phyla in the gut of the Assamese macaques, and over 98% of these bacterial taxa exhibited no significant seasonal differences in relative abundance and the community structure of gut microbiota. This may be related to their diet throughout the year containing over 90% of young leaves and fruits, and the intake of mature leaves and flowers closely associated with the gut microbiota lacks significant seasonal differences, which also corresponds to the relative stability of the gut microbiota. Additionally, rainfall and humidity are closely related to the gut microbiota, but their effect was insufficient to significantly fluctuate the gut microbiota, indicating that the climatic change is tolerable for the macaques. Combined with the feeding choices of these macaques in the limestone habitat, their digestive strategy from the perspective of gut microbiota was determined.