Oral administration of Lactiplantibacillus plantarum 22A-3 exerts anti-allergic activity against intestinal food allergy mouse models sensitized and challenged with ovalbumin

In recent years, researches on food components with anti-allergic effects have been gathering attention, because of the expectation for the establishment of a safe and effective treatment for food allergy. Previous studies have reported that Lactiplantibacillus plantarum 22A-3 (LP22A3) inhibited degranulation of mast cells and reduced IgE production. We have developed a gastrointestinal allergy system in which mice are sensitized by intraperitoneal and oral administration of OVA and then challenged by oral administration of high doses of OVA. As a result, an increase in the amount of IgE in the blood and a decrease in the temperature of the colon were confirmed, and it was clarified that food allergy was induced by oral administration of high dose of OVA as the challenge. Oral administration of LP22A3 ameliorated allergic responses significantly by reducing the amount of IgE in the blood and to recovered the decrease of rectal temperature. However, LP22A3 did not affect the intestinal barrier function. Administered LP22A3 significantly suppressed mRNA expression of OX40L and IL-4. These results suggested that LP22A3 suppressed Th2 differentiation and IL-4 production via downregulation of OX40L, and consequently suppressed IgE production. LP22A3 might provide a safe and effective treatment for allergic diseases due to ability modulating intestinal immune system.