Toll-Like Receptor Expression in Irritable Bowel Syndrome: On the Alert for a Microbial Threat?

Evidence suggests that mucosal and luminal factors, including low-grade immune activation, increased mucosal permeability and altered host-microbiota interactions, contribute to IBS pathophysiology. In this issue of the American Journal of Gastroenterology, Brint and colleagues provide the first evidence of increased expression of toll-like receptors (TLRs) in patients with IBS. TLRs are known to be involved in the translation of bacterial signals into anti-bacterial innate immune responses. These results hold promise for a better understanding of the role of microbiota and immune activation in the pathophysiology of IBS and also provide novel pharmacological targets for this common troublesome disorder.