Gut microbiota mediates dietary adaptation across spatially varying diets in the endangered Przewalski's gazelle (Procapra przewalskii).

The extreme and heterogeneous Qinghai-Tibet Plateau challenges wildlife survival. Przewalski's gazelle (Procapra przewalskii) is confined to the northeastern Plateau around Qinghai Lake, where habitat fragmentation exposes isolated populations to distinct plant resources. How this species adapts to dietary heterogeneity via internal physiology remains unclear. Here, we integrated dietary analysis, shotgun metagenomics, and untargeted metabolomics to examine relationships among diet, gut microbiome function, and metabolic outputs across three regions. We observed population-specific differences in plant consumption, gut microbial composition, and functional potential, notably in carbohydrate degradation, plant secondary metabolite transformation, and energy metabolism. Metabolomics revealed shifts in short-chain fatty acids and lipid- and energy-related pathways. Co-occurrence networks and partial least squares path modeling (PLS-PM) indicated diet influences metabolites indirectly via the gut microbiome as a key mediator. Our findings establish a "diet-gut microbiome-metabolic output" framework, highlighting microbial mechanisms underpinning local adaptation and informing conservation of endangered plateau species.