The alleviated symptoms in ovalbumin-allergic mice treated with selenium-enriched tea polysaccharide by modulation of intestinal flora and gut metabolites

Ovalbumin (OVA) in egg is one of the predominant causes of food allergy around the world. In the present study, the alleviating effect of selenium-enriched tea polysaccharide (Se-TPS) on OVA allergy was evaluated, and the underlying mechanistic insights were investigated. Se-TPS significantly alleviated the clinical manifestations and diarrhea of allergic mice, accelerated the recovery of jejunal injury, and decreased the immune organ index. Meanwhile, Se-TPS decreased the levels of immunoglobulin E (IgE), histamine, and IL-4 in serum, increased the levels of IFN-γ, and promoted the balance of Th1/Th2 cells. Furthermore, the intervention of Se-TPS reshaped the gut microbiota structure of OVA-allergic mice. Se-TPS increased the abundance of Lachnospiraceae_NK4A136_group, unclassified_f_Lachnospiraceae, and Alistipes, whereas decreased the Faecalibaculum abundance. Analysis of intestinal metabolites showed that Se-TPS treatment caused a significant increase in homocitrulline and 7a-hydroxyandrost-4-ene-3,17-dione levels. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment results indicated that Se-TPS treatment may alleviate allergic symptoms by enhancing the anti-inflammatory ability of OVA-allergic mice through neuroimmunity.