SCFAs, a class of crucial metabolites of intestinal microbiota, show anti-inflammatory activity by binding and activating endogenous receptors, such as GPR41 and GPR43, to prevent immune reactions, improve the level of IL-10 and inhibit the production of IL17, thus protecting the intestinal barrier, suppressing excessive signaling of TLR and alleviating IBD symptoms [59,60,61]. The gene discussed is IL17A; the disease is inflammatory bowel disease.