Oral administration of a mixture of probiotics protects against food allergy via induction of CD103+ dendritic cells and modulates the intestinal microbiota

Although the prevalence of food allergies is rising, the standard of care for these allergies is suboptimal. Probiotics have been reported to regulate the allergic immune response, but the underlying mechanisms are not fully understood. In this study, we aimed to evaluate the effect of a mixture of probiotics on food allergy in an ovalbumin (OVA)-induced murine model. Treatment with the probiotics attenuated OVA -induced allergic symptoms in mice. Flow cytometry analysis showed that oral administration of probiotics induced mucosal CD103(+) dendritic cells (DCs), which promoted differentiation of regulatory T cells (Tregs). 16S rRNA analysis revealed that the probiotics modulated the composition of microbiota, especially by increasing the proportion of the Deferribacteres and Verrucomicrobia phyla and the Mucispirillum and Clostridium XlVa genera, which in turn regulated the immune system. Our findings provide molecular insight into the application of a mixture of probiotics to alleviate food allergies and even gut immune homeostasis.