CLDN3 and colitis: Moreover, beneficial bacteria (probiotics) promote gut barrier integrity by specifically promoting CLDN3 expression.19 Other studies have shown similar positive association of CLDN3 expression with gut barrier integrity.38 These data, when combined with the fact that CLDN3 expression is markedly suppressed in IBD patients and murine models of colitis, emphasize the significance of promoting CLDN3 in improving the prognosis of IBD.