Novel Food Supplement Containing a Combination of Postbiotics and Plant-Derived Compounds Regulates Epithelial Barrier Integrity and Immune Response in Human Enterocytes

Background: Alterations of epithelial barrier integrity and immune response play a key role in the pathogenesis of allergic diseases and represent promising targets for nutritional interventions. Selected postbiotics and plant-derived compounds have been proposed as potential modulators of epithelial barrier and immune function. Methods: We investigated the effects of a novel food supplement combining heat-inactivated Lacticaseibacillus rhamnosus GG, butyrate, Quercetin, and Perilla frutescens extracts on epithelial barrier function and innate immunity in an experimental model of the human epithelial gut barrier. Results: Exposure to the food supplement resulted in epithelial barrier integrity enhancement, consisting of increased transepithelial electrical resistance, tight-junction protein expression, mucus production, and enterocyte differentiation. Moreover, the formulation markedly stimulated the expression of the innate immunity peptides β-defensin-2 and cathelecidin LL-37. Conclusions: The novel food supplement induces a beneficial modulation of the epithelial gut barrier and immune response. These findings support its potential use as a functional food strategy to restore mucosal homeostasis and to promote immune tolerance in allergic diseases.