In the co-culture model, human intestinal epithelial cells are cultured on transwell filters. In the basolateral compartment of these wells activated peripheral blood mononuclear cells are added. This model may resemble the effector immune response in the intestinal mucosa of food allergic patients after oral challenge. The capacity of epithelial cells to modulate the effector immune response is studied upon epithelial exposure to oligosaccharides, probiotics or toll like receptor agonists. In addition, epithelial permeability can be studied. Cell lines and primary cells are available to address IgE mediated mast cell degranulation and mediator release. Modulation of this allergic effector response by poly-unsaturated fatty acids is currently under investigation.