Gut microbiota plays an important role in health and metabolism and is affected by diet. This means that the gut microbiota of sympatric species is different due to niche separation. In this study, high-throughput 16S rRNA sequencing was used to study the gut microbiota of sympatric François’ langurs and rhesus macaques using 57 fecal samples collected from the limestone forests of the Guangxi Chongzuo White-headed Langur National Nature Reserve. The results indicated no significant difference in gut microbial diversity between the two primate species. However, marked differences were found in gut microbial composition. François’ langurs had a greater abundance of Firmicutes, Verrucomicrobia, TM7, and Planctomycetes, and a lower abundance of Bacteroidetes, Tenericutes, Proteobacteria, WPS-2, Fibrobacteres, and Lentisphaerae than rhesus macaques. At the genus level, François’ langurs had a greater abundance of norank Ruminococcaceae, unclassified Clostridiales, norank Clostridiales, Akkermansia, and unclassified Ruminococcaceae, whereas macaques had a higher proportion of Prevotella, Coprococcus, and Oscillospira. Predictive functional analysis reveals that the gut microbiota of François’ langurs is richer in cellular processes pathways than that of rhesus macaques, which were richer in genetic information processing and organismal systems. In summary, significant differences in gut microbiota were evident between the two sympatric primate species, which is probably due to the diet separation and morphology of the digestive tract. This suggests niche separation between the sympatric limestone-dwelling rhesus macaques and François’ langurs.

肠道菌群在健康和新陈代谢中起重要作用，并受饮食影响。这意味着同位物种的肠道菌群由于生态位分离而不同。在这项研究中，采用高通量16S rRNA测序技术，利用从广西崇左白头叶猴国家级自然保护区的石灰岩森林收集的57份粪便样品，研究了同胞弗朗索瓦氏叶猴和恒河猴的肠道菌群。结果表明两种灵长类动物的肠道微生物多样性无显着差异。然而，发现肠道微生物组成存在明显差异。François的叶猴比猕猴猕猴桃有更多的菌毛，Verrucomicrobia，TM7和Planctomycetes，而拟杆菌，Tenericutes，Proteobacteria，WPS-2，纤维杆菌和Lentisphaerae的丰富度较低。Akkermansia，和未分类Ruminococcaceae，而猕猴有较高比例的普氏菌，Coprococcus和Oscillospira。预测性功能分析表明，弗朗索瓦叶猴的肠道菌群比恒河猕猴的肠道过程中的细菌过程更丰富，而猕猴的遗传信息处理和生物系统中的丰富。综上所述，两种同属灵长类动物在肠道菌群上存在明显差异，这很可能是由于饮食分离和消化道形态所致。这表明居住在石灰岩的恒河猴和弗朗索瓦叶猴之间的利基分离。