Gut and genital tract microbiomes: Dysbiosis and link to gynecological disorders

Abstract

Every year, millions of women are affected by genital tract disorders, such as bacterial vaginosis (BV), endometrial cancer, polycystic ovary syndrome (PCOS), endometriosis, and uterine fibroids (UFs). These disorders pose a significant economic burden on healthcare systems and have serious implications for health and fertility outcomes. This review explores the relationships between gut, vaginal, and uterine dysbiosis and the pathogenesis of various diseases of the female genital tract. In recent years, reproductive health clinicians and scientists have focused on the microbiome to investigate its role in the pathogenesis and prevention of such diseases. Recent studies of the gut, vaginal, and uterine microbiomes have identified patterns in bacterial composition and changes across individuals’ lives associated with specific healthy and diseased states, particularly regarding the effects of the estrogen–gut microbiome axis on estrogen-driven disorders (such as endometrial cancer, endometriosis, and UFs) and disorders associated with estrogen deficiency (such as PCOS). Furthermore, this review discusses the contribution of vitamin D deficiency to gut dysbiosis and altered estrogen metabolism as well as how these changes play key roles in the pathogenesis of UFs. More research on the microbiome influences on reproductive health and fertility is vital.

The role of probiotics in improving menstrual health in women with primary dysmenorrhoea: A randomized, double-blind, placebo-controlled trial (the PERIOD study)

“…Gut dysbiosis refers to any perturbation in the diversity and/or number of healthy populations of intestinal microbiota that can occur through diet, age, ethnicity, medication, smoking, and alcohol intake. 37 Gut dysbiosis affects beta-glucuronidase enzyme activity, which is the main deconjugation pathway of estrogen in the intestinal microbiota. This, in turn, affects estrogen metabolism and exacerbates estrogen-driven conditions like endometriosis, which is another major cause of dysmenorrhea.…”

Mechanisms of endometrial aging: lessons from natural conceptions and assisted reproductive technology cycles

“…Though long held to be a sterile environment, mounting evidence now supports the existence of a physiologic endometrial microbe population which is impacted by hormonal changes and represents another element of the embryo-endometrial interface ( Toson et al, 2022 ). Multiple studies support a connection between the female reproductive tract microbiome and infertility ( Rowe et al, 2020 ; Cela et al, 2022 ; Elkafas et al, 2022 ), but the mechanisms by which changes in the endometrial microbiome contribute to female infertility remain unknown. Further, although the bacterial composition of the endometrium is known to be influenced by age ( Fujii and Oguchi, 2023 ), the role of probiotics and the endometrial microbiota have not been well-studied in the context of age-related decline in fertility.…”

The Upper Reproductive System Microbiome: Evidence beyond the Uterus

“…Imbalances in microbial composition have been demonstrated to affect both neighboring and remote anatomical locations. 63 For instance, gut microbiome has been correlated to cardiovascular, gastrointestinal, and central nervous system related diseases like Alzheimer's and Parkinson's. 64 Additionally, disturbances in the gut and vaginal microbiome have been hypothesized to play key roles in cervical, uterine, and ovarian cancer, 65 although their roles in the initiation or development of these pathologies remain unclear ( Table 1 ).…”