CLDN2 and ulcerative colitis: Intragastric administration of QCWZD significantly upregulated serum MSP level and RON expression in the colon, reduced the pAkt levels, increased colonic occluding and ZO-1 expression, and downregulated claudin-2 expression, so as to inhibit the intestinal inflammation, improve the intestinal mucosal barrier function, and finally achieve the purpose of repairing intestinal mucosa and treating ulcerative colitis.