Airway Exposure as Another Sensitization Route for Triggering Food Allergy Induced by Egg Ovalbumin Oral Challenge: The Potential of Lung-Gut Immune Communication

Food allergies have become an increasingly serious public health issue worldwide. Ovalbumin (OVA) is the primary egg allergen, and while it has long been linked to oral sensitization, new research about the dual allergen exposure hypothesis shows that airway allergen exposure is a contributor to food allergy pathogenesis. In this study, a murine food allergy model with airway sensitization was established. Airway OVA sensitization with oral challenge induced dose- and duration-dependent allergic phenotypes, Th2 and Th17 skewing, and mast cell and eosinophil infiltration in the lungs and intestines. The microbiota dysbiosis was manifested by reduced levels of Lactobacillus . Further results suggest that CCL25/CCR9-mediated T cell gut-homing may be involved in the intestinal allergic reactions induced by airway sensitization with an oral challenge. These findings confirm that airway food allergen sensitization with oral challenge drives lung-gut immune communication, providing new experimental evidence for safety assessment of food proteins through nonoral sensitization routes.