The Qaidam Basin on the Qinghai–Tibet Plateau is an extreme arid environment, posing severe survival challenges. The goitered gazelle (Gazella subgutturosa) is a keystone species in this fragile ecosystem, yet the ecological role of its gut microbiota and its associations with environmental drivers remain poorly understood. We collected fecal samples from gazelles across seven regions of the basin. Metagenomic sequencing was employed to characterize the gut microbiome. Statistical analyses (Mantel tests, multiple regression on matrices, co-occurrence networks) were used to link microbial composition and function with key environmental factors. The gut microbiota was dominated by fiber-degrading phyla (Firmicutes, Bacteroidota) and enriched in metabolic pathways, aligning with a high-fiber diet. Regarding environmental drivers of gut microbial composition variations, isothermality and soil organic carbon were significant predictors, likely via vegetation and environmental inoculation. Regarding environmental drivers of gut microbial function variations, winter solar radiation was uniquely associated with metabolic function without altering microbial composition, suggesting a functional plasticity—the capacity to shift metabolic profiles independently of taxonomic turnover—in response to environmental variation. The gut microbiota of the goitered gazelle exhibits a stable core composition alongside environmentally responsive functional modules. This suggests the microbiome may serve as a significant mediator of host resilience, highlighting adaptation as a dynamic interplay between host, microbiome, and environment. These insights are crucial for microbiome-assisted conservation.

This study focused on the links between soil physicochemical properties and the gut microbiota of goitered gazelles (Gazella subgutturosa) in the hyper-arid Qaidam Basin. By integrating 16S rRNA gene sequencing, soil physicochemical analysis (11 soil indicators), and microbial source tracking (FEAST) on samples of feces (n = 58), soil (n = 35), and water (n = 35) collected from six typical regions. We systematically revealed the mechanisms by which soil properties influence the gut microbiome of wildlife in an arid desert ecosystem based on source tracking and Multiple Regression on distance Matrices (MRM) analysis. The results showed that soil total phosphorus (TP) was significantly positively correlated with the α-diversity of gut microbiota (coefficient = 0.4/0.23/0.332; p < 0.05), while soil organic carbon (SOC) was significantly negatively correlated (coefficient = −0.44/−0.436; p < 0.05), indicating that soil nutrients indirectly predict host microbial diversity by regulating vegetation productivity and forage quality. β-diversity analysis further demonstrated that spatial heterogeneity in soil pH (coefficient = 0.3083; p < 0.05) and TP (coefficient = 0.227; p < 0.05) significantly drove the structural differentiation of gut microbial communities. Source-tracking results based on FEAST revealed significant regional differences in the proportional contribution of environmental microorganisms to the gut microbiota, with individuals in resource-poor habitats (ALK region) exhibiting higher input from soil microbes (8.0672% ± 6.9291%; p < 0.05). In conclusion, this study clarifies the ecological mechanism by which soil physicochemical properties regulate the diversity and composition of herbivore gut microbiota through a “soil–plant–food–gut microbiota” cascading pathway, providing important empirical evidence for understanding animal–microbe–environment interactions and adaptive evolution in extreme environments.