show Abstracthide AbstractThe microbial composition of host-associated microbiomes is influenced by various factors, including co-evolutionary interactions, host genetics, domestication processes, and the environment. In this study, we investigated the contribution of environmental microbiota from freshwater bodies to the gastrointestinal microbiomes of wild khulans (Equus hemionus hemionus).We performed 16S rRNA gene sequencing to analyze the microbial composition using PacBio technology.Our results showed limited microbial sharing between wild khulans and the water and sediment samples from waterholes, suggesting that the environment may not act as a major source of gut bacteria for khulans nor do khulans contaminate water sources extensively. The higher microbial diversity and richness in wild khulan microbiomes (versus captive) may be attributed to their adaptation to the challenging nutritional environment in the Gobi desert. Captive khulans, unlike their wild counterparts, displayed reduced microbial diversity that could be influenced by dietary changes during captivity.