Nasal instillation of probiotic extracts inhibits experimental allergic rhinitis

Aim: Allergic rhinitis (AR) is a common disease. The therapeutic efficacy of AR needs to be improved. This study aims to evaluate the effects of local administration of probiotic extracts on inhibiting experimental AR. Methods: Epithelial cells (ECs) were primed by exposing to Clostridium butyricum extracts (CBe) in the culture to upregulate the expression of IL-10. A mouse AR model was developed to assess the therapeutic potential of CBe in AR. Results: CBe markedly induced the expression of IL-10 in ECs. Co-culture of naive B cells with CBe-primed ECs significantly increased IL-10 expression in the B cells (iB10 cells). The iB10 cells showed immune suppressive function in suppressing effector CD4⁺ T-cell proliferation. Treatment with nasal drops containing CBe efficiently inhibited experimental AR in mice. Conclusion: Local administration of CBe can efficiently inhibit experimental AR.