S-equol reduces the incidence of menopausal symptoms, osteoporosis, skin aging, hair loss, prostate cancer, and ovarian cancer by selectively activating estrogen receptors, and has a variety of biological and clinical uses (Lee et al., 2018).The findings suggest that the differential microbiota may play an important role in the occurrence of melasma as a characteristic part of the microbiota in these patients. The gene discussed is ESR1; the disease is freckles.