Characteristics of Microbiota in Different Segments of the Digestive Tract of Orange-Collared Keelback (Rhabdophis himalayanus)

The gastrointestinal tract of animals plays an essential role in digestion and nutrient absorption. The diversity of gut microbiota is critical for maintaining the physiological functions of animals. However, current research has focused primarily on mammals; research on the gut microbiota of reptiles, particularly snakes, remains limited. This study utilized metagenomic sequencing and untargeted metabolomics to investigate the microbial community composition and functional potential in the stomach, large intestine, and small intestine of the Orange-collared Keelback (Rhabdophis himalayanus). The results demonstrate that the three most dominant phyla in the R. himalayanus gut microbiota are Pseudomonadota, Actinomycetota, and Bacillota. Moreover, analysis of microbial communities across the stomach, small intestine, and large intestine shows no significant differences in α-diversity and β-diversity among the three regions. Linear Discriminant Analysis Effect Size (LEfSe) reveals significant differences in the gut microbiota abundance. MetaStats analysis further reveals significant differences in the abundance of both microbial taxa and CAZymes. Although overall metabolite profiles did not differ significantly among gastrointestinal regions, pairwise analyses identified differentially abundant metabolites associated with amino acid, lipid, nucleotide, and cofactor metabolism. Gut microbiota from different parts of the digestive tract may reveal a unique characteristic of the gut microbiome of R. himalayanus and the impact of microbial community structure on function. Collectively, these findings expand our understanding of gastrointestinal microbial communities and associated functional potential in an understudied snake species.