Evidently, whether the trypsin is secreted by T. spiralis or by inflamed intestine, AZ3451 could inhibit the trypsin-induced activation of PAR2, thereby reducing the phosphorylation level of ERK1/2 and up-regulating the expression of intestinal TJs proteins, consequently decreasing intestinal permeability and ameliorating intestinal inflammation. Here, F2RL1 is linked to gastroenteritis.