KAR significantly upregulated the expression of AHR in macrophages, further promoting IL-10 secretion, through establishing a 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced mouse model of IBS; meanwhile, clinical experiments showed that AHR expression in macrophages of IBS patients was negatively correlated with IBS severity, therefore, KAR may be an important dietary polyphenol for future intervention in the development of IBS. The gene discussed is AHR; the disease is irritable bowel syndrome.