Equol Production Status is An Effective Predictor of Nonalcoholic Steatohepatitis in Women

Equol is a metabolite of daidzein, a major soybean isoflavone with estrogenic and antioxidant activities. As the production of equol depends on the presence of certain members of the intestinal microflora, not all individuals can produce equol. The incidence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) increases in menopausal women, and estrogen is associated with the progression of NAFLD/NASH. Therefore, the status of equol production might also be related to the pathogenesis of NAFLD/NASH in women. We, thus, examined the relationship between NASH histological features and equol production. Thirty-eight NAFLD patients who underwent liver biopsy were included in this study. In women, the degree of fibrosis and ballooning in nonproducers was significantly higher than that in producers. The percentage of nonproducers with NAFLD activity score (NAS) ≥5 was significantly higher than that of producers. None of the histological features were significantly different between nonproducers and producers in men. Decision tree analysis identified the predictors of NAS ≥5 in women. The status of equol production was the strongest predictor, followed by fasting glucose. Equol can be noninvasively detected in urine, suggesting its application as a screening test for predicting the diagnosis and progression of NASH in women.