OCLN and colitis: In a rat model of colitis, baicalin was found to increase the expression of IL‐10 by increasing the number of Treg cells in the lamina propria of the colon, while decreasing the number of Th17 cells and the expression of IL‐17A in the colon, and then increased the expression levels of ZO‐1 and Occludin, as well as Muc2 protein in the mucosal layer, which may be associated with increased concentrations of butyric acid in the colon (Zhu et al. 2020).