A possible explanation for the differences in cytokine release of PI-IBS patients in comparison to healthy controls could be a differential expression of Toll-like receptors (TLRs) on immune cells, as IBS patients displayed altered expressions of intestinal TLR2, TLR4, TLR7, and TLR8 receptors [28–30]. This evidence concerns the gene TLR4 and irritable bowel syndrome.