Their function in chronic inflammation is well known, as stated by Dlugoz et al., where the authors concluded that there is an upregulation in TLRs in the physiopathology of IBS due to their findings of the expression of TLR4, TLR5, and TLR9 in the small bowel mucosa of 23 patients with IBS [16]. Here, TLR4 is linked to irritable bowel syndrome.