Dietary interventions for modulating the gut microbiome in PCOS management.

Background: Polycystic ovary syndrome (PCOS) is a multifactorial endocrine disorder affecting about 10% of reproductive-age women. It is defined by insulin resistance, androgen excess, and chronic inflammation, which drive both reproductive and metabolic complications. Growing evidence suggests that gut microbiome dysbiosis contributes to PCOS by altering intestinal permeability, promoting endotoxemia, and worsening hormonal and metabolic dysfunction. Diet, as a modifiable factor, may offer a therapeutic route to restore microbial balance and improve outcomes. Objectives: This review aims to (1) synthesize evidence on how diet shapes gut microbiome composition in PCOS; (2) evaluate the effects of specific dietary patterns on microbial diversity, insulin sensitivity, lipid metabolism, and hormonal regulation; and (3) identify dietary components that may improve clinical outcomes. Methods: Evidence from observational studies, randomized trials, and meta-analyses was reviewed to assess how dietary interventions influence gut microbiome modulation and PCOS outcomes. Dietary patterns-including the Mediterranean diet, low-glycemic index diets, anti-inflammatory diets, time-restricted eating, and probiotic supplementation-were examined for their effects on microbiota and metabolic or hormonal measures. Results: Dietary interventions can beneficially alter gut microbiota, reduce systemic inflammation, improve insulin sensitivity, and lower androgen levels. The Mediterranean diet enhances microbial diversity and is associated with reduced PCOS risk. Low-glycemic index diets improve metabolic and hormonal profiles by lowering insulin demand. Anti-inflammatory diets and time-restricted eating may restore microbial rhythmicity and reduce inflammatory and endocrine imbalances. Probiotic supplementation, particularly with Lactobacillus and Bifidobacterium, strengthens gut integrity and benefits metabolic and hormonal outcomes. A multi-component dietary plan integrating high-fiber foods, probiotics, anti-inflammatory nutrients, low glycemic load, and structured eating patterns is proposed. Conclusion: Modulating the gut microbiome through diet is a promising, non-invasive, cost-effective strategy for PCOS management. By targeting insulin resistance, androgen excess, and inflammation, nutrition-based interventions can improve metabolic and reproductive outcomes. Long-term randomized trials are needed to strengthen causal evidence and guide personalized dietary approaches.