The Implication of Mechanistic Approaches and the Role of the Microbiome in Polycystic Ovary Syndrome (PCOS): A Review

Abstract

As a complex endocrine and metabolic condition, polycystic ovarian syndrome (PCOS) affects women’s reproductive health. These common symptoms include hirsutism, hyperandrogenism, ovulatory dysfunction, irregular menstruation, and infertility. No one knows what causes it or how to stop it yet. Alterations in gut microbiota composition and disruptions in secondary bile acid production appear to play a causative role in developing PCOS. PCOS pathophysiology and phenotypes are tightly related to both enteric and vaginal bacteria. Patients with PCOS exhibit changed microbiome compositions and decreased microbial diversity. Intestinal microorganisms also alter PCOS patient phenotypes by upregulating or downregulating hormone release, gut-brain mediators, and metabolite synthesis. The human body’s gut microbiota, also known as the “second genome,” can interact with the environment to improve metabolic and immunological function. Inflammation is connected to PCOS and may be caused by dysbiosis in the gut microbiome. This review sheds light on the recently discovered connections between gut microbiota and insulin resistance (IR) and the potential mechanisms of PCOS. This study also describes metabolomic studies to obtain a clear view of PCOS and ways to tackle it.

Association between gut microbiota and menstrual disorders: a two-sample Mendelian randomization study

“…Escherichia/Shigella is an Enterobacteriaceae bacterium that has been shown to cause intestinal inflammation and increased intestinal permeability when overexpressed, making it a recognized pathogenic bacterium ( Mukherjee et al, 2023 ). Its secreted lipopolysaccharide induces acute intestinal injury, increases blood–brain barrier permeability, and activates neuroinflammation ( Dong et al, 2021 ).…”

“…In the gastrointestinal system, the gut microbiota plays an important role in digestion regulation, but its importance goes much beyond that. The structure of the gut microbiota affects the onset and progression of metabolic and endocrine diseases ( Mukherjee et al, 2023 ). Randomized controlled trials of the gut microbiota, as opposed to observational studies, may aid in proving causation.…”

Inflammation mediates the effect of adiposity and lipid metabolism indicators on the embryogenesis of PCOS women undergoing in vitro fertilization/intracytoplasmic sperm injection

“…Studies have elucidated that excessive adipose tissue can cause the imbalance of the immune system and activate pro-inflammatory processes, characterized by high levels of TNF-α, pro-inflammatory interleukins, and chemokines ( 3 , 37 – 39 ). The mechanisms triggering the inflammatory state in obese women have also been extensively studied, including cell enlargement and death in the obese tissue, imbalanced adipokine production, fatty acid dyshomeostasis, local hypoxia, mitochondria dysfunction, dysbiosis in the gut microbiome, mechanical stress, and endoplasmic reticulum stress ( 3 , 19 , 40 ). Moreover, epigenetic regulations, including DNA methylation, histone acetylation, and changes in noncoding RNA levels, have been reported to affect the inflammatory response and oxidative stress in PCOS women ( 16 ).…”

Relationship between Polycystic Ovary Syndrome and Metabolic Syndrome

“…Further research is needed to determine if there is a difference in the microbiome of Mexican women with PCOS and PCOS/MetS compared to healthy women. 35…”