Systematic Review of Gut Microbiota Composition, Metabolic Alterations, and the Effects of Treatments on PCOS and Gut Microbiota Across Human and Animal Studies

Aya Hanna¹Hassan Abbas¹Fayez Yassine¹Alia Albush¹Melhem Bilen^1,2,3*

• ¹Department of Experimental Pathology and Immunology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
• ²Center for Infectious Diseases Research, American University of Beirut Medical Center, Beirut, Beyrouth, Lebanon
• ³WHO Collaborating Center for Reference and Research on Bacterial Pathogens, Beirut, Lebanon

Polycystic ovary syndrome (PCOS) is an endocrine disorder affecting around 12% of women globally, associated with infertility and various comorbidities. Emerging evidence suggests a crucial role of gut microbiota in PCOS pathophysiology. This systematic review analyzes human and animal studies comparing gut microbiota composition, gut-derived metabolites, and treatment interventions in PCOS patients versus healthy controls. A comprehensive literature search was conducted using PubMed, Scopus, and Web of Science. Our analysis revealed decreased alpha diversity in PCOS patients, with more pronounced beta diversity changes in animal models. Specific bacterial taxa, such as Bacteroides vulgatus, Escherichia-Shigella, and Lactobacillus, were implicated in PCOS pathogenesis. Discrepancies between human and animal studies highlight the need for humanized mouse models. Interventions like probiotics and fecal microbiota transplantation (FMT) showed varying efficacy, with FMT emerging as a promising but invasive option. Alterations in gut-derived metabolites, including short-chain fatty acids and bile acids, underscore the complex interplay between PCOS and metabolic pathways. Further research with standardized methods and larger sample sizes is needed to elucidate the microbiome’s role in PCOS and its potential as a therapeutic target.