Table_5_Seasonal variations in the gut microbiota of white-headed black langur (Trachypithecus leucocephalus) in a limestone forest in Southwest Guangxi, China.xlsx

Investigating gut microbiota is important for understanding the physiological adaptation of animals to food availability changes in fragmented habitats and consequently providing new ideas for the conservation of endangered wild animals. In this study, we explored the gut microbiota of the endangered white-headed black langur (Trachypithecus leucocephalus), which is endemic to the limestone forests of Southwest Guangxi, China, to understand its adaptation strategies to seasonal changes in habitat using 16S rRNA sequencing. Our results revealed significant seasonal variations in the gut microbiota of white-headed black langurs. In particular, the alpha diversity was higher in the rainy season than in the dry season, and the beta diversity was significantly different between the two seasons. At the phylum level, the relative abundance of Firmicutes, Actinobacteriota, and Proteobacteria was higher in the dry season than that in the rainy season, whereas that of Bacteroidetes, Spirochaetota, and Cyanobacteria was significantly higher in the rainy season than that in the dry season. At the family level, Oscillospiraceae and Eggerthellaceae were more abundant in the dry season than in the rainy season, whereas Lachnospiraceae, Ruminococcaceae, and Monoglobaceae were more abundant in the rainy season than in the dry season. These results could have been obtained due to seasonal changes in the diet of langurs in response to food plant phenology. In addition, the neutral community model revealed that the gut microbiota assembly of these langurs was dominated by deterministic processes and was more significantly affected by ecological factors in the dry season than in the rainy season, which could be linked to the higher dependence of these langurs on mature leaves in the dry season. We concluded that the seasonal variations in the gut microbiota of white-headed black langurs occurred in response to food plant phenology in their habitat, highlighting the importance of microbiota in responding to fluctuating ecological factors and adapting to seasonal dietary changes.

探究肠道菌群对于理解动物适应破碎生境中食物可用性变化之生理机制具有重要意义，进而为濒危野生动物的保育提供新的思路。本研究以我国西南石灰岩森林特有物种——濒危白头叶猴（Trachypithecus leucocephalus）为研究对象，通过16S rRNA测序技术，解析其肠道菌群在生境季节性变化中的适应策略。研究发现，白头叶猴肠道菌群在季节性变化中表现出显著的差异。具体而言，在雨季，其α多样性高于旱季，而β多样性在两个季节间存在显著差异。在门水平上，厚壁菌门（Firmicutes）、放线菌门（Actinobacteriota）和变形菌门（Proteobacteria）在旱季的相对丰度高于雨季，而拟杆菌门（Bacteroidetes）、螺旋菌门（Spirochaetota）和蓝藻门（Cyanobacteria）在雨季的相对丰度显著高于旱季。在科水平上，拟杆菌科（Oscillospiraceae）和埃格特菌科（Eggerthellaceae）在旱季的丰度高于雨季，而毛螺菌科（Lachnospiraceae）、瘤胃球菌科（Ruminococcaceae）和单胞菌科（Monoglobaceae）在雨季的丰度高于旱季。这些结果可能是由于叶猴在食物植物物候变化下对饮食季节性变化的适应。此外，中性群落模型揭示，这些叶猴的肠道菌群组装主要受确定性过程支配，且在旱季比雨季更受生态因素的影响，这可能与其对成熟叶片的更高依赖性有关。据此，我们得出结论，白头叶猴肠道菌群的季节性变化是对其生境中食物植物物候变化的响应，凸显了微生物群在应对波动性生态因素和适应季节性饮食变化中的重要性。