Characteristics of the Gut Microbiota in Different Segments of the Gastrointestinal Tract of Big-Eyed Bamboo Snake (Pseudoxenodon macrops)

Snakes are model animals to study energy balance, but studies on the gut microbiota of the animals are rather scarce. To fill the gap, we used metagenome sequencing to investigate the microbial community composition and adaptability in the stomach, small intestine, and large intestine of Big-eyed Bamboo Snake. The results showed that there was no significant differences in α-diversity among different gastrointestinal segments. Pseudomonadota, Bacteroidota, and Bacillota were the most abundant phyla. The dominant genera in the stomach and small intestine were similar, while those in the large intestine were distinct. The abundance of <i>Bacteroides, Citrobacter</i> and <i>Clostridium</i> was significantly higher in the large intestine than in the small intestine. The LEfSe analysis revealed that the small intestine had the most characteristic bacteria, with a total of 20 species, while the stomach and large intestine each had two species. Additionally, in the current study, we also focused on the impact of the microbial community structure on functions through functional annotations in the KEGG and CAZy. There were significant differences in the KEGG level 2 between the stomach and the small intestine. The LEfSe analysis revealed the differences in the CAZy level 2 between the large intestine and the small intestine. Overall, our study provided a comparative and contrastive analysis of the gut microbiota in different gastrointestinal segments of Big-eyed Bamboo Snake, offering valuable insights for the co-evolution mechanism of the host and the gut microbiota.