OCLN and atherosclerosis: Gut microbiota dysbiosis can impair the intestinal barrier function by disrupting intestinal tight junction proteins including zonula occludens-1 (ZO-1) and occludin, thereby increasing intestinal permeability and allowing more lipopolysaccharide (LPS) to enter the circulation, which in turn stimulates the toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signal cascades, thus activating various inflammatory factors and potentially resulting in atherosclerosis [5].