Anti-inflammatory effect of dietary fibers is Toll-like receptor dependent

A range of dietary carbohydrate fibers are present in fruits and grains and thus constitute an important part of our diet. As such these fibers are responsible for many health beneficial effects and are attributed to have anti-inflammatory effects in the gut. However, the molecular mechanism of interaction between dietary fibers and the immune system is not known yet. Recently, we have shown that β2-1 fructans protect the barrier function of epithelial cells through activation of Toll-Like receptors (TLR). Therefore, we hypothesized that the carbohydrate fibers interact with innate immune receptors like TLR in the intestine to impart their health beneficial effects. TLRs play an important role in maintaining the tight junctions in intestine and also immune homeostasis of the gut. To analyze the interaction of dietary fibers with TLRs we used TLR reporter cell lines. Only particular dietary fibers were found to inhibit TLR activation, leading to reduced NF-κB activation. To confirm the anti-inflammatory effects, we studied the effect of the identified dietary fibers administration in a Doxorubicin induced mucositis model. Doxorubicin is a chemotherapeutic agent which in addition to its anti-cancer effect, causes intense inflammation in the intestine leading to mucositis. Administration of the selected dietary fibers in mice was found to be beneficial to reduce inflammation symptoms of mucositis. Thus, we propose a novel anti-inflammatory food intervention for doxorubicin induced mucositis.