The genital system of women has been colonized by various species of microorganisms since the beginning of life. In the postnatal period, the method of birth is important; when a child is born naturally, passing the female genital tract, it acquires bacteria present in the mother’s vagina, and when through the cesarean section, the child’s organism is first colonized by the mother’s skin microbiota and hospital strains. In female newborns during the first days after the natural birth, the presence of Lactobacillus rods, which acidify the vagina, is readily observed. Later, however, they disappear and during the childhood period, the pH of the vagina becomes alkaline. Only in the period of puberty and full puberty, as a result of the increase in the level of estrogen in the female body, the amount of Lactobacillus strains increases and this continues up to the menopause period, when pathogenic strains begin to dominate. The female vagina is home to not only numerous bacteria, but also fungi, including mainly Candida yeast and filamentous fungi at a lower extent. Dysbiosis of the vagina may be caused by the predominance of pathogenic bacteria over Lactobacillus, resulting in bacterial vaginosis or excess of Candida yeast, resulting in candidiasis. An effective method leading to the homeostasis of the female sexual system is the use of vaginal probiotics, which should consist of strains characteristic to a given female population.