TJP1 and irritable bowel syndrome: Zonula occludens (ZO-1) (unpaired two-tailed t-test, t8 = 4.822, p = 0.0013) and occludin (unpaired two-tailed t-test, t8 = 4.544, p = 0.0019) expression levels were lower in the IBS group compared to those in the CON group (Figure 1M–O).