TNF and irritable bowel syndrome: Although the underlying mechanism was unclear, those cytokines have been reported to play important roles via Toll-like receptors (TLR) in the development of IBS symptoms, including the effect on peripheral and central nervous systems to develop hypersensitivity and gut hypomotility (TNF-α), stimulation of gut submucosal neurons (IL-6), intestinal barrier integrity (TNF-α, IL-6) and maintenance of gut homeostasis (IL-1β, IL-6, IL-10) [16, 17, 29].