The expression levels of Muc1, Muc3, claudin-1, and Zo-1 were increased in WTPO and fat-1 transgenic mice, indicating that omega-3 fatty acids improve the intestinal epithelial barrier; thus, preventing the infiltration of bacterial endotoxins into the lamina propria of the intestinal tract and attenuating colon inflammation. The gene discussed is CLDN1; the disease is colitis.