<i>Akkermansia muciniphila</i>attenuated lipopolysaccharide-induced acute lung injury by modulating the gut microbiota and SCFAs in mice

Abstract

Gut microbiota are closely related to lipopolysaccharide (LPS)-induced acute lung injury (ALI). <i>Akkermansia muciniphila</i> (<i>A. muciniphila</i>) maintains the intestinal barrier function and regulates the balance of reduced glutathione/oxidized glutathione. However, it may be useful as a treatment strategy for LPS-induced lung injury. Our study aimed to explore whether <i>A. muciniphila</i> could improve lung injury by affecting the gut microbiota. The administration of <i>A. muciniphila</i> effectively attenuated lung injury tissue damage and significantly decreased the oxidative stress and inflammatory reaction induced by LPS, with lower levels of myeloperoxidase (MDA), enhanced superoxide dismutase (SOD) activity, decreased pro-inflammatory cytokine levels, and reduced macrophage and neutrophil infiltration. Moreover, <i>A. muciniphila</i> maintained the intestinal barrier function, reshaped the disordered microbial community, and promoted the secretion of short-chain fatty acids (SCFAs). <i>A. muciniphila</i> significantly downregulated the expression of TLR2, MyD88 and NF-kappa B (<i>P</i> < 0.05). Butyrate supplementation demonstrated a significant improvement in the inflammatory response (<i>P</i> < 0.05) and mitigation of histopathological damage in mice with ALI, thereby restoring the intestinal butyric acid concentration. In conclusion, our findings indicate that <i>A. muciniphila</i> inhibits the accumulation of inflammatory cytokines and attenuates the activation of the TLR2/Myd88/NF-κB pathway due to exerting anti-inflammatory effects through butyrate. This study provides an experimental foundation for the potential application of <i>A. muciniphila</i> and butyrate in the prevention and treatment of ALI.