Under normal circumstances, female vaginal microenvironment is affected by menstrual cycle, hormone level (including pregnancy status), diseases (diabetes, immunosuppressive diseases), antibiotic drug use, sexual partners and other factors. The pH value of the vaginal microenvironment is about 3.8-4.5. The main microorganisms commonly found in the vagina include Lactobacillus, Staphylococcus, Streptococcus, Escherichia coli, Candida, and Gardnerella vaginalis.