Hypoxic exposure makes plateau migrators susceptible to high altitude polycythemia (HAPC). Astragalus membranaceus (AM) is an edible and medicinal plant with remarkable immunomodulatory activities. The purpose of this study was to discover if AM could be a candidate for the prevention of HAPC and its mechanism. Here, network pharmacology was applied to screen active compounds, key targets, and enriched pathways of AM in the treatment of HAPC. Molecular docking evaluated the affinity between compounds and core targets. Subsequently, the mechanisms of AM were further verified using the hypoxia exposure-induced mice model of HAPC. The network pharmacology analysis and molecular docking results identified 14 core targets of AM on HAPC, which were predominantly mainly enriched in the HIF-1 pathway. In the HAPC animal models, we found that AM inhibited the differentiation of hematopoietic stem cells into the erythroid lineage. It also suppressed the production of erythrocytes and hemoglobin in peripheral blood by reducing the expression of HIF-1α, EPO, VEGFA, and Gata-1 mRNA. Furthermore, AM downregulated the expression of IL-6, TNF-α, and IFN-γ mRNA, thereby alleviating organ inflammation. In conclusion, AM supplementation alleviates hypoxia-induced HAPC in mice, and TNF-α, AKT1, HIF-1α, VEGFA, IL-6, and IL-1B may be the key targets.

Background: High-altitude hypoxia disrupts intestinal homeostasis by impairing the epithelial barrier, triggering inflammation, and promoting microbial translocation. Berberine (BER), a natural isoquinoline alkaloid with antimicrobial and anti-inflammatory properties, has shown potential in protecting intestinal integrity; however, its efficacy under hypoxic conditions and its interaction with the gut microbiota remain unclear. Methods: A chronic hypoxia mouse model was used to investigate the protective effects of BER against intestinal injury. Microbiota dependency was assessed through antibiotic-mediated depletion and fecal microbiota transplantation (FMT), combined with 16S rRNA gene sequencing, metabolomics, and immune profiling. The functional role of a BER-responsive bacterium was validated by oral administration in antibiotic-treated mice. Results: BER supplementation restored epithelial barrier integrity, including tight junctions, antimicrobial peptide expression, and goblet cell function, while reducing inflammation and epithelial apoptosis under hypoxic conditions. BER also reshaped gut microbial composition and network structure, accompanied by coordinated alterations in cecal metabolites, particularly purine metabolites and bile acids. Microbiota depletion abolished the protective effects of BER, whereas FMT from BER-treated donors recapitulated these effects, confirming a microbiota-dependent mechanism. Among BER-responsive taxa, Bacteroides thetaiotaomicron (B. thetaiotaomicron) emerged as a key effector, correlating with metabolite profiles and barrier integrity. Oral administration of B. thetaiotaomicron alone protected against hypoxia-induced intestinal injury, restoring mucin production and antimicrobial peptide expression, and attenuating inflammation and apoptosis. Mechanistically, both BER and B. thetaiotaomicron reactivated bile acid–FXR signaling and normalized intestinal immune homeostasis, including T-cell subset distribution. Conclusion: These findings demonstrate that BER protects against hypoxia-induced intestinal injury through microbiota-dependent metabolic and immune regulation. B. thetaiotaomicron acts as a central mediator of this protective effect, highlighting microbiota-targeted strategies as potential interventions for maintaining intestinal homeostasis under hypoxic stress.