Gut microbial remodeling as an ecological strategy for host metabolic management under environmental stress on the Xizang Plateau.

The adaptive responses of gut bacteria and host metabolism in Xizang sheep to the decline in forage quality and the extremehigh-altitude environment remain largely unclear. This study utilized Xizang sheep as a model, and employed 16S rRNA sequencing, metabolomics, and RT-qPCR to investigate changes in the composition and functional pathways of the gut bacteria, as well as hepatic and muscular metabolism, in response to these stressors. The results indicated that in response to these stressors, the complexity of the gut microbial network in Xizang sheep was reduced, yet the overall positive correlations within the community were enhanced, accompanied by a significant increase in the abundance of Fibrobacterota and Lachnoclostridium, while the abundance of Bacteroides decreased. Furthermore, metabolomic analysis based on gene co-expression network (WGCNA) revealed that the glycerophospholipid metabolism pathway in the liver was suppressed, while the lysine degradation pathway was activated in muscle. These findings reveal the physiological adaptations of the gut bacteria, liver, and muscle of Xizang sheep in response to seasonal variations in grass quality at high altitudes. This research provides a theoretical framework for understanding ruminant adaptation to high-altitude environments.