Abnoos Mokhtariardekani
1 
, Farzin Banei
2 , Zahra Boshagh
3 , Pegah Ranjbari
4 , Zahra Hamidi Madani
5 , Elahe Zaremoghadam
6,7 , Sara Abutalebi Nasrabad
8* 1 Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Science and Physiology Research Center, Kerman University of Medical Sciences, Kerman, Iran
2 Department of Neurology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
3 Department of Microbiology, Arak Islamic Azad University of Science and Research, Arak, Iran
4 Department of Obstetrics and Gynecology, School of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
5 Department of Obstetrics and Gynecology, Reproductive Health Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
6 Department of Internal Medicine, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran
7 Digestive Diseases Research Institute, Shariati Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
8 Department of Obstetrics and Gynecology, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Abstract
The gut microbiome, a complex ecosystem of trillions of microorganisms, has a critical role in metabolic regulation, immune function, and hormonal balance, systems all implicated in polycystic ovary syndrome (PCOS). Evidence suggests that women with PCOS exhibit distinct gut microbial profiles, including reduced microbial diversity, decreased abundance of beneficial bacteria, and increased levels of pro-inflammatory and endotoxin-producing species. These shifts are associated with insulin resistance, obesity, low-grade inflammation, and androgen excess—hallmarks of PCOS. Furthermore, gut microbiota influences bile acid metabolism, short-chain fatty acid production, and gut barrier integrity, thereby modulating systemic inflammation and endocrine function. Interventions such as probiotics, prebiotics, dietary modifications, and fecal microbiota transplantation show promise in ameliorating PCOS symptoms through microbiota modulation. Despite these advances, challenges remain, including heterogeneity in study designs, small sample sizes, and the need for longitudinal data.