Seasonal and Regional Dietary Heterogeneity Is Associated With Gut Microbiota Differentiation in Przewalski's Gazelle (Procapra przewalskii).

Wild ungulates on the Qinghai-Tibet Plateau experience seasonal shifts in food resources, yet integrated evidence linking diets with gut microbiota and metabolic profiles remains limited. We combined fecal DNA metabarcoding, 16S rRNA sequencing, metagenomics, and untargeted metabolomics to analyze diet, gut microbiota composition, functional pathways, and fecal metabolic profiles in 82 fecal samples of Przewalski's gazelle (Procapra przewalskii) from three regions. Seasonal comparisons were conducted within each region and regional comparisons within each season. Winter diets showed regional specificity, with Poaceae and Cyperaceae enriched in the N region, Poaceae and Fabaceae in the S region, and Iridaceae in the W region, whereas summer diets shifted toward forb families including Asteraceae, Apiaceae, Brassicaceae, and Polygonaceae. Gut microbiota composition and KEGG Level 3 functions differed between seasons. Representative taxa enriched in winter included UCG-007 within Oscillospiraceae, Akkermansia, Mailhella, and Papillibacter, whereas taxa enriched in summer included Candidatus Saccharimonas, [Eubacterium]_brachy_group, and Colidextribacter. Representative pathways included Biosynthesis of cofactors, Biosynthesis of nucleotide sugars, Biosynthesis of various nucleotide sugars, and Glyoxylate and dicarboxylate metabolism in winter, whereas representative pathways in summer included the Phosphotransferase system (PTS), Ribosome, Aminoacyl-tRNA biosynthesis, and Peptidoglycan biosynthesis. Fecal metabolomic profiles differed among regions within both seasons, and dietary dissimilarity was significantly correlated with metabolomic, genus-level microbial, and KEGG Level 3 functional dissimilarities. Correlation analyses linked LEfSe-identified plant families to dominant genus-level taxa and KEGG Level 3 pathways. Together, these results support a close link between dietary variation and changes in gut microbiota composition, functional potential, and fecal metabolic profiles.