Recombinant Echinococcus granulosus myophilin alleviates airway inflammation in mice with ovalbumin-induced allergic asthma via the gut microbiota-metabolite-immune axis

BACKGROUND: Parasitic infections or their secreted components exhibit therapeutic effects against certain allergic diseases. Allergic asthma is a chronic inflammatory airway disease with potentially severe symptoms and increasing prevalence worldwide. Recombinant Echinococcus granulosus myophilin (rEg.myophilin) induces a Th1 immune response in mouse spleens; however, the effects and mechanisms of rEg.myophilin in allergic asthma remain unclear. METHODS: We investigated the anti-inflammatory effects of rEg.myophilin on airway inflammation in mice with ovalbumin (OVA)-induced allergic asthma through histopathology, flow cytometry, and enzyme-linked immunosorbent assay. 16S rRNA sequencing and non-targeted metabolomics of mouse fecal samples and correlation analyses of microbiota, metabolites, and inflammatory indicators were used to explore the mechanistic role of rEg.myophilin in allergic asthma. RESULTS: rEg.myophilin significantly ameliorated OVA-induced allergic airway inflammation. Pathological findings revealed a marked reduction in lung inflammatory cell infiltration, collagen deposition, and mucus secretion. rEg.myophilin also corrected the imbalance in Th1/Th2 cell ratios in lung tissues and reduced the abundance of Tenericutes and Candidatus_Arthromitus. Among the 19 metabolites with significant differences among Con, OVA, and OVA+rEg.myophilin groups, those linked to linoleic acid metabolism, indicating that rEg.myophilin may act through the linoleic acid metabolic pathway to alleviate allergic asthma. Spearman's correlation analysis revealed positive/negative correlations between several differential metabolites, differential microbiota, and immune indicators. CONCLUSIONS: rEg.myophilin alleviates OVA-induced allergic asthma in mice by modulating interactions among intestinal microbiota, metabolites, and immune cells. This research provides theoretical insights and novel biological targets for the prevention and treatment of allergic asthma.