# Soy Isoflavones and PCOS: Role in Hormonal and Metabolic Mechanisms
## 4 Polycystic Ovary Syndrome and Soy Isoflavones
### Gut Microbiota  
The gut microbiota is currently an intensively studied element in the pathogenesis of PCOS. Numerous studies have shown significant differences in the composition of the gut microbiota in patients with PCOS compared to healthy women [25; 26; 27]. A recently published systematic review and meta-analysis [181] confirmed that women with PCOS have reduced microbial evenness and phylogenetic diversity of the gut microbiome. A decreased abundance of bacteria from the genera _Lachospira_ and _Prevotella_ has been observed, along with an increased presence of _Bacteroides_, _Parabacteroides_, _Lactobacillus_, _Fusobacterium_, and _Escherichia/Shigella_. The gut dysbiosis observed in PCOS patients--manifested, among other things, by a lower abundance of bacteria producing short-chain fatty acids (SCFAs), involved in bile acid metabolism and glucose regulation--may indicate an imbalance \begin{table}
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**Authors,** & **Study Design,** & **Characteristics of the Study** & **Intervention/Aim of the Study** & **Main Results** & **Conclusions** \\ \hline Amant & Experimental & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ Amant & Experimental & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ Amant & Experimental & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ Amant & Experimental & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ Amant & Experimental & & & & & \\  & & & & & \\  & & & & & \\ Amant & Experimental & & & & & \\ Amant & Experimental & & & & \\  & & & & & \\ Amant & Experimental & & & & \\  & & & & & \\  & & & & & \\ Amant & Experimental & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ Amant & Experimental & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\ [PERSON] et al., & (two-way & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\
2024, [138] & randomisation) study; & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & \\  & & & & & \\  & & & & & \\  & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & \\  & & & & & \\  & & & & & \\  & & & & & \\  & & & & \\  & & & & & \\  & & & & \\ \end{tabular}
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Table 4: _Cont._in the gut microbiota. This imbalance is characterised by a shift towards dominance of pro-inflammatory microorganisms at the expense of anti-inflammatory species [182]. The \"Dysbiosis of Gut Microbiota\" (DOGMA) hypothesis is one of the conceptual frameworks aiming to explain the mechanisms underlying PCOS development [183]. It proposes that quantitative and qualitative changes in the gut microbiota composition may lead to impaired intestinal barrier integrity, increasing its permeability and enabling the translocation of lipopolysaccharidesaccharides (LPS) into the systemic circulation. The subsequent activation of the immune system may interfere with insulin receptor function, leading to hyperinsu-linemia, which in turn stimulates excessive ovarian androgen production and disrupts follicular development. Despite the high content of isoflavnes in soy products, their bioavailability is limited--only a small fraction is absorbed in the small intestine. The majority reaches the large intestine where it is further metabolised by the intestinal microbiota [24]. The pharmacological effects of isoflavnes may be enhanced or diminished depending on the ability of the gut microbiota to produce equal--the biologically active metabolite of daidzein. Individuals capable of equal production are referred to as \"equol producers\". It is estimated that approximately 25-50% of the population exhibits this capacity, with a higher prevalence in Asian populations, while in Western populations, the average is around 35% [72; 73; 74]. Research suggests a synergistic interaction between soy isoflavnes and the gut microbiota [17; 184; 185].