The study by Piche et al. indicated that an impaired gut barrier was a critical factor in the predisposition to intestinal diseases, such as irritable bowel syndrome (IBS), and the results demonstrated that mucosal soluble mediators can reproduce functional permeability changes and molecular alterations, including zonula occludens-1 (ZO-1) mRNA expression, as observed in patients with IBS [74]. This evidence concerns the gene TJP1 and irritable bowel syndrome.