4. Discussion
4.1 Diversity of the gut microbiota of wild and captive R.
brelichi
The living environment of wild animals is mainly caused by environmental
changes (captive breeding or semi-release, etc.) caused by the
protection of species characteristics, which affect the gut microbial
composition of wild animals to a certain extent, especially endangered
wild animals (Zeng, 2020). Multiple studies have shown that the richness
and diversity of the gut microbiota were reduced to varying degrees
after captivity in Macaca fascicularis (Sawaswong et al., 2021),Moschus berezovskii (Li et al., 2017), R. roxellanae (Zhao
et al., 2023), and Ailuropoda melanoleuca (Cheng et al., 2020),
with some of the natural flora potentially being lost. In this study,
the gut microbial richness and diversity of captive R. brelichi were significantly higher than those of wild R. brelichi , which
was consistent with the results of a previous study of captive and wildR. roxellanae by Wang et al. (2023). As a typical leaf-eating
primate, R. brelichi has access to a more uniform diet in the
wild but a richer range of food in captivity, including leaves from a
variety of trees, as well as a range of fruits, vegetables, and sources
of protein. We believe that this factor may be an important explanation
for the richer and more diverse gut microbiota of captive R.
brelichi (Campbell et al., 2020). In addition, captive breeding limits
the roaming and foraging behaviors of R. brelichi , and increases
their close contact with each other and with humans. It is speculated
that captivity increases the likelihood of the transmission of
intestinal microbiota through oral and fecal routes, and potentially
pathogenic microorganisms may be more abundant in the gut microbiota ofR. brelichi in captivity.
4.2 Composition and difference of gut microbiota in wild and captive