Food allergens affect the intestinal tight junction permeability in inducing intestinal food allergy in rats.

The intestinal tract plays an important role in food allergy and the intestinal mucosa barrier is critical for maintenance of its function. The underlying mechanisms of how food allergens modulate the intestinal permeability in inducing intestinal food allergy remain elusive. The aim of this study was to explore the mechanism of how food allergens influence the function of intestinal barrier and induce intestinal food allergy. Ovalbumin (OVA) was chosen to establish intestinal food allergy models in juvenile and adult rats that were confirmed by IgE and IgG assay. Intestinal tissue morphology was analyzed by HE staining. Intestinal permeability was dynamically monitored using a Lactulose (L)-Mannitol (M) assay. The morphology of the tight junctions in the intestinal mucosa barrier were analyzed under TEM. The expression of key molecules in tight junction regulation was evaluated by Real-time PCR. We found: 1) The sensitization rate in juvenile rats was higher than in adult rats; 2) Intestine fluff erosion was more serious in juvenile rats than in adult rats in the duodenum and ileum; 3) Intestinal permeability was severely damaged, according to the results of the Lactulose (L)-Mannitol (M) assay; 4) Tight junction damage on the mucosal barrier was observed; Real-time PCR results showed that the expression of some key molecules that are involved in tight junction regulation was also affected. Our data suggested that the allergy sensitization rate of Ovalbumin (OVA) in the juvenile group is higher than in adults and food allergens may increase intestinal mucosal permeability through intestinal tight junction regulation in inducing intestinal food allergy.