PLOD1 and polycystic ovary syndrome: Besides, researches indicate that the gut microbiota-bile acid interleukin-22 axis or the brain-gut axis may be the potential mechanism in the development progress of PCOS, and the dysbiosis of the gut microbiota is strongly relevant to endocrine disorders, including LH, FSH, LH/FSH, anti-Mullerian hormone (AMH), and testosterone, in PCOS patients [38, 42–44].