Effects of Soy Isoflavones, Resistant Starch and Antibiotics on Polycystic Ovary Syndrome (PCOS)-Like Features in Letrozole-Treated Rats

Abstract

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in reproductive-aged women. Recently, various dietary interventions have been used extensively as a novel therapy against PCOS. In the present study, we show that soy isoflavone metabolites and resistant starch, together with gut microbiota modulations, were successful in decreasing the severity of PCOS-like reproductive features while increasing the expression of gut barrier markers and butyric acid in the gut. In the letrozole-induced PCOS model rats, the intake of both 0.05% soy isoflavones and 11% resistant starch, even with letrozole treatment, reduced the severity of menstrual irregularity and polycystic ovaries with a high concentration of soy isoflavones and equol in plasma. Antibiotic cocktail treatment suppressed soy isoflavone metabolism in the gut and showed no considerable effects on reducing the PCOS-like symptoms. The mRNA expression level of occludin significantly increased with soy isoflavone and resistant starch combined treatment. Bacterial genera such as Blautia, Dorea and Clostridium were positively correlated with menstrual irregularity under resistant starch intake. Moreover, the concentration of butyric acid was elevated by resistant starch intake. In conclusion, we propose that both dietary interventions and gut microbiota modulations could be effectively used in reducing the severity of PCOS reproductive features.

Modified Banxia Xiexin Decoction Ameliorates Polycystic Ovarian Syndrome With Insulin Resistance by Regulating Intestinal Microbiota

“…firstly proposed the hypothesis of “gut barrier-endotoxemia-inflammation”, considering that changes in dietary conditions can lead to intestinal microbiota disorders, impaired gut mucosal barrier, and increased intestinal mucosal permeability, which allow the produced “lipopolysaccharide (LPS)” to enter the bloodstream and then cause IR and PCOS ( Vrieze et al., 2010 ; Tremellen and Pearce, 2012 ). The disturbance of the microbiota can induce abnormal glucose metabolism, hyperandrogenemia, and abnormal follicular development in PCOS ( Xie et al., 2016 ; Qi et al., 2019 ; Han et al., 2021 ), and a healthy gut microbiota protects against reproductive and metabolic dysregulation ( Torres et al., 2019 ; Liyanage et al., 2021 ).…”

Efficacy of Flavonoids on Animal Models of Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

“…A total of 18 articles [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ] investigated 7 types of flavonoids on PCOS animal models. All the included studies were conducted between 2015 and 2022.…”

“…Results from the subgroup analyses suggest that only one study which used soy isoflavone did not show a statistic reduction of the count of cystic follicles. In this study, the treatments were divided into three groups: the soy isoflavone group, the resistant starch group, and the soy isoflavone combined with resistant starch group, which individually showed a significant reduction in cyst formation [ 31 ]. We only included the soy isoflavone group as the intervention method, which may have led to the heterogeneity.…”

“… Forest plot of flavonoids for the count of corpus luteum [ 31 , 36 , 37 , 38 , 39 , 41 , 44 , 46 , 47 ]. …”

Extension of the Life Span by Acarbose: Is It Mediated by the Gut Microbiota?

“…Resistant starch can resist degradation by digestive enzymes in the small intestine and reach the large intestine, suggesting that resistant starch modulates gut homeostasis, similar to acarbose [ 18 ]. Resistant starch can increase the abundance of SCFAs, especially butyric acid [ 19 , 20 ]. The effect of acarbose on longevity may be mediated by glucose physiology and microbial activity in the intestine.…”