OCLN and polycystic ovary syndrome: Dysbiosis of intestinal flora impairs the intestinal barrier and decreases the expression of the tight junction proteins occludin and zonula occludin-1 (ZO-1) in the intestinal mucosa, thus promoting increased intestinal permeability and the release of endotoxins into the circulation, which bind to the corresponding receptors to conduct signals, leading to chronic inflammation, insulin resistance (IR) and hyperandrogenemia (HA), affecting immune and metabolic homeostasis (Lam et al., 2012).