Lactobacillus rhamnosus RL-H3-005 ameliorates Enterococcus faecium-induced pulmonary inflammation. - GreenMedInfo Summary

Pulmonary inflammation represents a serious global health challenge with increasing incidence. Probiotic supplementation has emerged as an innovative therapeutic strategy targeting the gut-lung axis, although its underlying mechanisms remain incompletely understood. This study investigated the effects of Lactobacillus rhamnosus RL-H3-005 on pathogenic Enterococcus faecium E745-induced pulmonary inflammation in mice. RL-H3-005 supplementation significantly alleviated lung injury through suppression of oxidative stress and macrophage M1 polarization. Gut microbiota analysis revealed that RL-H3-005 enriched beneficial genera including Bacteroides and Muribaculum, enhanced short-chain fatty acid (SCFAs) production, and strengthened intestinal barrier function, consequently reducing lipopolysaccharides (LPS) and pro-inflammatory cytokine levels. Targeted metabolomics demonstrated that RL-H3-005 restored serum metabolic profiles, particularly in valine, leucine, and isoleucine biosynthesis and degradation pathways. Significant negative correlations were observed between RL-H3-005-enriched metabolites and M1 macrophage markers, suggesting a gut-lung regulatory mechanism. These findings highlight RL-H3-005 as a promising intervention for inflammatory lung conditions through gut microbiota-mediated modulation of host metabolism.