Abstract:

The microecological balance of the female reproductive tract is the core of maintaining reproductive health, and the genus Lactobacillus, as the dominant flora, plays a crucial role. In the vagina, the dominant species such as Lactobacillus crispatus and Lactobacillus jensenii can maintain environmental stability through acid production, secretion of antibacterial substances, and immune regulation, which is a sign of a healthy microecology. In contrast, the dominance of Lactobacillus iners or a state of high diversity increases the risks of bacterial vaginosis, persistent human papilloma virus (HPV) infection, and preterm birth. However, the function of Lactobacillus iners is affected by the strain source and host status. Multiple 16S rRNA sequencing studies have shown that a low-biomass microbiota community can be detected in the endometrium, and there is still controversy over whether Lactobacillus is the dominant genus in its community composition. Uterine cavity microecological dysbiosis (decrease in Lactobacillus, increase in pathogenic bacteria, or enrichment of specific bacteria) is closely related to chronic endometritis, intrauterine adhesions, and endometriosis. Currently, in terms of intervention strategies, the application of specific probiotic strains or targeted engineered bacteria has potential in the adjuvant treatment of bacterial vaginosis or HPV infection, prevention of recurrence after intrauterine adhesion surgery, and promotion of endometrial repair. However, there are still challenges in the level of existing evidence, the precision of strain selection, and the translational application of engineered bacteria. In the future, in-depth research at the strain and functional gene levels, combined with multi-omics and strict methodologies, is needed to promote the precise diagnosis and treatment of the female reproductive tract microecology.

Key words: Lactobacillus, Gastrointestinal microbiome, RNA, ribosomal, 16S, Dysbiosis, Genital diseases, female