A single species bacterial therapy reduces type 2 immune responses in the gut to prevent food allergy

Abstract The rising prevalence of food allergy is strongly correlated with dysbiosis the gut microbiome. Rescuing this by reintroducing specific bacteria a promising method to prevent or treat allergy. We have shown that monocolonization Anaerostipes caccae, species representative healthy infant microbiota, protects against an allergic response milk protein b-lactoglobulin (BLG). Recently we developed synbiotic bacterial therapy (A. caccaeplus prebiotic lactulose) which rescues phenotype gnotobiotic mice colonized fecal dysbiotic, cow’s (CMA) infant. Synbiotic treatment minimizes anaphylactic intragastric BLG challenge and reduces circulating BLG-specific IgE IgG1. To understand how single bacterium regulates mucosal immunity during onset IgE-mediated first examined alarmin response. CMA express high transcript levels both IL25and TLSPin ileal epithelial cells after sensitization plus cholera toxin. abrogated response, potentially via increased mucus production. also reduced proportion number T follicular (Tf) helper in ileal-draining lymph node (LN) Tf-regulatory colon-draining LN, suggesting role T/B cell regulation. Ongoing experiments are examining affects localization expansion producing tissues including Peyer’s patches mesenteric LNs. These findings will help uncover mechanisms specific, protective inform development effective live biotherapeutics.