In the study of untargeted fecal metabolomics, we found that Methallenestril and PS (22:5 (4Z, 7Z, 10Z, 13Z, 16Z) / LTE4) were found to be significantly increased in the PCOS model group and significantly decreased after r-irisin intervention, suggesting that these two metabolites may be important markers of r-irisin affecting the PCOS phenotype. Here, FNDC5 is linked to polycystic ovary syndrome.