Effects of pelvic microbiome features on female reproductive health

Among the many causes of female infertility, there are features of the composition of the "normal" microbiome, characterized by: interspecific changes in the ratio of representatives of the genus Lactobacillus; quantitative imbalance of lactobacilli with representatives of other types of microorganisms contained in the vagina and uterus; pelvic inflammatory disease (PID); tendency to form biofilms contributing to the progression of antibiotic resistance, etc. Pelvic organs contain their own typical microbiome, which accounts for 9% of the total bacterial population in women. Among the spectrum of microorganism species, the female sex tract is mostly dominated by Lactobacillus species, which are considered among the most important microorganisms. Although the existence of the vaginal microbiome has long been established, the upper section of the reproductive tract was considered a sterile environment, with the assumption that the presence of bacteria is associated with adverse clinical manifestations. However, modern research has revealed certain patterns of the microbiome colonizing the uterus, endometrium, fallopian tubes, ovaries and placenta. Bacterial colonization of these sites is different from vaginal, despite evidence that vaginal bacteria can ascend into the upper genital tract through the cervix. The review presents systematic scientific evidence on the microbiome of the lower and upper reproductive tract of women. The issues of pelvic microbiome influence on a woman's reproductive health are considered. The feasibility of assessing the state of the pelvic microbiome at all stages of monitoring the health of a woman in the system of gynecological institutions, which can become a useful screening tool for successful reproductive function, is justified.