Gut bacterial and fungal communities of François' langur (Trachypithecus francoisi) changed coordinate to different seasons

Jinyuan Liu ¹ Qixian Zou ² Diyan Li ¹ Tao Wang ³ Jialiang Han ^4*

• ¹ School of Pharmacy, Chengdu University, Chengdu, China
• ² Mayanghe National Nature Reserve Administration, Tongren, China
• ³ School of Basic Medical Sciences, Chengdu University, Chengdu, China
• ⁴ Office of Academic Affairs, Chengdu University, Chengdu, China

François' langur (Trachypithecus francoisi), an endangered primate, inhabits the limestone forests of Vietnam and China. The gut microbiota plays a critical role in maintaining gastrointestinal stability and enabling hosts to adapt to diverse dietary conditions. This microbial community is highly dynamic, undergoing substantial changes in response to variations in food resources and seasonal shifts. However, the specific impacts of these variations on the gut bacterial and fungal communities of François' langur remain poorly understood. To examine seasonal differences in the gut bacterial and fungal communities of François' langur, we collected fresh fecal samples from 22 individuals residing in the Mayanghe National Nature Reserve, Guizhou Province, China. We analyzed these samples to evaluate the composition of the gut microbiota across four seasons. Our results revealed significant seasonal changes in the gut microbiota at both the phylum and genus levels, indicating that seasonal factors strongly influence the microbial diversity and structure in François' langur. The α-diversity of the gut bacterial community in François' langur is notably higher during warmer seasons compared to colder months, while the fungal community exhibits the opposite trend, with greater diversity in colder seasons. These findings demonstrate that seasonal variations significantly influence the diversity and structure of François' langur gut microbiota. Among bacteria, Akkermansia, a mucin-degrading genus commonly associated with vertebrate gut health, is more prominent in the summer, accounting for 1.3% of the total gut microbiota. In the fungal community, Cercophora, known for its ability to break down plant biomass, primarily cellulose, may contribute to the degradation of plant-based dietary components. Within the gut, these fungi likely enhance the host's ability to extract energy from a plant-rich diet. This study provides essential insights into the seasonal dynamics of François' langur gut microbiota. These findings offer a valuable reference for future research on this endangered species and serve as a foundation for developing informed conservation strategies.