Poria cocos polysaccharide alleviates multidrug-resistant Klebsiella pneumoniae -induced acute lung injury by modulating the gut–lung axis via gut microbiota remodeling

< 0.05). Mechanistically, PCP restored intestinal barrier function by upregulating tight junction proteins (occludin and claudin-1) and mucosal defense factors (SIgA and MUC-2), and reversed gut dysbiosis by restoring microbial diversity and enriching beneficial taxa. These protective effects were largely attenuated in pseudo-germ-free mice, suggesting that the protection offered by PCP against MDR-KP-induced ALI is dependent on the gut microbiota. In conclusion, oral PCP alleviates MDR-KP-induced ALI through a gut microbiota-mediated pathway by remodeling the gut microbiota, reinforcing intestinal barrier integrity, and regulating the gut-lung axis, providing a novel gut-targeted therapeutic strategy against drug-resistant KP infections.