Background. Food additives are responsible for certain allergic types of symptoms. Here Caco-2 cell monolayers were used as a model of the intestinal epithelium for the study of the effect of a food grade surfactant. We determined whether or not the presence of a surfactant enhances the transportation of food allergens across human intestinal epithelial Caco-2 cells. Methods: This study investigated sucrose monoester fatty acids, which are a food grade surfactant. As an in vitro model of human epithelial cells, Caco-2 cells were grown in monolayers and exposed to different doses of the surfactant in conjunction with ovomucoid, a major egg white allergen. The integrity of the monolayer was assessed by measuring transepithelial electrical resistance (TEER). The permeability of tight junctions and transport of the antigen were studied. Results: TEER correlated with the permeability of tight junctions. TEER significantly decreased upon exposure to a surfactant, indicating an increase in ovomucoid permeability without degradation. The surfactant induced shortening in microvilli, actin disbandment and structural separation of tight junctions. The results indicate that food grade surfactants can increase the paracellular uptake of food allergens. Copyright (C) 2003 S. Karger AG, Basel.