Abstract
BACKGROUND: The gut microbiota is regarded as one of the key factors regulating host health. The gut microbiota and its connection to fecal metabolites are crucial for supporting fetal development and ensuring maternal health during reproductive stages. Although studies have examined Asian elephants, the composition and function of the gut microbiota in pregnant and non-pregnant captive Asian elephants have not been reported. METHODS: We compared the fecal microbiota and fecal metabolites of pregnant (G1), non-pregnant (never gotten pregnant after reaching sexual maturity, G2), and subadult (G3) captive Asian elephants using metagenomic sequencing and untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) metabolomics. RESULTS: We found significant differences in the gut microbiota among the G1, G2, and G3 groups. The phylum Bacteroidetes showed notable differences between G1 and G2. The analysis of fecal metabolomics revealed significant differences in 49 metabolites between G1 and G2, of which 25 were upregulated and 24 were downregulated. These results suggested significant differences in the composition of gut microbiota and fecal metabolites during reproductive stages, while gut microbial diversity remained stable. These findings inform our ongoing research on the potential health conditions of captive Asian elephants, with the aim of better understanding the role of the gut microbiota in reproductive regulation.