White-lipped deer (Cervus albirostris) is a nationally protected wild animal species in China, as well as a unique and endangered species, according to the International Union for Conservation of Nature (IUCN) Red List. Captivity may alleviate the pressure from poaching and contribute to the repopulation and conservation of the population in the wild. The gut microbiota is described as a complex, interactive internal system that has effects on diseases of the host, with many interactions. However, the influence of captivity on the composition and assembly process of gut microbiota in white-lipped deer is unclear. This study applied high-throughput 16S rRNA sequencing technology to determine differences in the gut microbiota between captive (CW) and wild (WW) white-lipped deer. We used the null model, neutral community model, and niche width to identify whether captivity affects the composition and assembly process of gut microbiota. The results show that WW has a higher number of Firmicutes and a lower number of Bacteroidetes compared with CW at the phylum level, and it has more opportunistic pathogens and specific decomposition bacteria at the genus level. Principal coordinate analysis also indicated significant differences in the composition and function of gut microbiota in CW and WW. Moreover, the results reveal that captivity shifts the ecological assembly process of gut microbiota by raising the contribution of deterministic processes. In conclusion, our results demonstrate that captivity might potentially have an unfavorable effect on white-lipped deer by continually exerting selective pressure.

The gut microbiota in animals is a dynamic ecosystem influenced by both the host itself and the environment it inhabits. It is known that short-term captivity can significantly impact the gut microbiota of plateau zokors, leading to substantial inter-individual variation. However, the specific changes in the assembly process of the gut microbiota in plateau zokors during captivity remain unclear. In this study, we conducted a comparative analysis on the assembly process of the gut microbiota in 22 male plateau zokors from the same location in Qinglin Township, Datong County, Qinghai Province, before (W) and after (L) laboratory rearing. We performed a single-factor correlation network analysis on the top 50 genera with relative abundance in each group. The results revealed that captivity increased the complexity of the gut microbiota in plateau zokors, indicating a higher number of interactions between different microbial species. However, this increase in complexity was accompanied by a decrease in stability, suggesting a higher degree of variability and potential disruption in the microbial community. According to the results of the neutral community model, the gut microbiota of plateau zokors in the W had a higher Nm value (Nm = 48,135) compared to the L (Nm = 39,671), indicating that species dispersal of the gut microbiota was greater in the wild than in captivity. In the wild, the modified stochasticity ratio (MST) was less than 0.5, suggesting that deterministic processes dominated. However, after 15 days of laboratory rearing, the MST became greater than 0.5, indicating a shift toward stochastic processes, and this difference was highly significant (p < 0.001). This differs from research related to aboveground animals. This study provides theoretical support for the application of gut microbiota in subterranean endangered species.

The gut microbiota is integral to the health and adaptability of wild herbivores. Interactions with soil microbiota can shape the composition and function of the gut microbiota, thereby influencing the hosts’ adaptive strategies. As a result, soil microbiota plays a pivotal role in enabling wild herbivores to thrive in extreme environments. However, the influence of soil microbiota from distinct regions on host’s gut microbiota has often been overlooked. We conducted the first comprehensive analysis of the composition and diversity of gut and soil microbiota in goitered gazelles across six regions in the Qaidam Basin, utilizing source tracking and ecological assembly process analyses. Significant differences were observed in the composition and diversity of soil and gut microbiota among the six groups. Source tracking analysis revealed that soil microbiota in the GangciGC (GC) group contributed the highest proportion to fecal microbiota (8.94%), while the Huaitoutala (HTTL) group contributed the lowest proportion (1.80%). The GC group also exhibited the lowest α-diversity in gut microbiota. The observed differences in gut microbial composition and diversity among goitered gazelles from six regions in the Qaidam Basin were closely tied to their adaptive strategies. Ecological assembly process analysis indicated that the gut microbiota were primarily influenced by stochastic processes, whereas deterministic processes dominated most soil microbial groups. Both the differences and commonalities in gut and soil microbiota play essential roles in enabling these gazelles to adapt to diverse environments. Notably, the utilization pattern of soil microbiota by gut microbiota did not align with regional trends in gut microbial α-diversity. This discrepancy may be attributed to variations in environmental pressures and the gut’s filtering capacity, allowing gazelles to selectively acquire microbiota from soil to maintain homeostasis. This study highlights the significant regional variation in gut and soil microbiota diversity among goitered gazelle populations in the Qaidam Basin and underscores the critical role of soil-derived microbiota in their environmental adaptation.

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.