GHRL and polycystic ovary syndrome: It was found that Ghrelin and PYY were significantly lower in PCOS patients compared with normal women, while serum LH levels and LH/FSH ratio were significantly reduced after successful probiotic transplantation, and improved PCOS-related clinical indicators and increased SCFA levels; while no significant changes were seen in serum LH and SCFA levels in the unsuccessful probiotic transplantation group (Zhang J. et al., 2019).