Protective effect of Bifidobacterium infantis CGMCC313-2 on ovalbumin-induced airway asthma and β-lactoglobulin-induced intestinal food allergy mouse models

AIM To determine whether oral administration of Bifidobacterium infantis CGMCC313-2 (B. infantis CGMCC313-2) inhibits allergen-induced airway inflammation and food allergies in a mouse model. METHODS Ovalbumin (OVA)-induced allergic asthma and β-lactoglobulin-induced food allergy mouse models were used in this study. Following oral administration of B. infantis CGMCC313-2 during or after allergen sensitization, histopathologic changes in the lung and intestine were evaluated by hematoxylin and eosin (HE) staining. In the allergic asthma mouse model, we evaluated the proportion of lung-infiltrating inflammatory cells. OVA-specific IgE and IgG1 levels in serum and cytokine levels in bronchoalveolar lavage fluid (BALF) were also assessed. In the food allergy mouse model, the levels of total IgE and cytokines in serum were measured. RESULTS Oral administration of B. infantis CGMCC313-2 during or after allergen sensitization suppressed allergic inflammation in lung and intestinal tissues, while the proportion of infiltrating inflammatory cells was significantly decreased in the BALF of allergic asthma mice. Moreover, B. infantis CGMCC313-2 decreased the serum levels of total IgE in food allergy mice, and reductions in IgE and IgG1 were also observed in OVA-induced allergic asthma mice. The expression of interleukin-4 (IL-4) and IL-13 in both serum and BALF was suppressed following the administration of B. infantis CGMCC313-2, while an effect on serum IL-10 levels was not observed. CONCLUSION B. infantis CGMCC313-2 inhibits the secretion of allergen-induced IgE, IL-4 and IL-13, and attenuates allergic inflammation.