In addition, the overactivation of O-antigen repeat unit biosynthesis, which is involved in the synthesis of bacterial surface antigens, may lead to enhanced antigenicity of gut bacteria, triggering an exaggerated local immune response in the gut and exacerbating intestinal inflammation. This pathway was significantly downregulated in the MPH group, suggesting that Bu Xu Ping Chuan膏 (a traditional Chinese medicine) may reduce the systemic inflammatory burden in COPD patients by inhibiting the potential for endotoxin synthesis within the microbiota and decreasing the production and release of LPS. This finding is consistent with the observed trend of reduced abundance of the Escherichia-Shigella genus (Gram-negative bacteria) at the genus level, indicating an intrinsic consistency.