Modulation of Vaginal Microbiota by Lactobacillus Sp As a Probiotic and Immunomodulatory Agent in Postmenopausal Women with Bacterial Vaginosis

Postmenopausal women experience hormonal changes, particularly in estrogen and progesterone levels. The reduction or even cessation of estrogen secretion in postmenopausal women leads to an increased dominance of pathogenic bacteria in the vagina, which during the premenopausal period was inhibited by Lactobacillus sp. The presence of Lactobacillus in the vaginal epithelium acts as a barrier against external pathogens and produces metabolic byproducts that are unfavorable for the growth of other bacteria. The availability of glycogen, which is influenced by estrogen levels, supports the presence of Lactobacillus as an energy source. This association explains why women entering menopause are at increased risk of developing bacterial vaginosis. In addition, it is known that female reproductive hormones regulate both innate and adaptive immune responses and modulate endocrine functions that influence Th1 and Th2 cytokines, suppress excessive inflammation, and restore homeostasis.

This study conduct to investigate the effects of probiotic therapy on the vaginal microbiota changes in menopausal women and its impact on immunological profiles. Administering Lactobacillus sp. probiotics is expected to modulate bacterial growth disrupted during perimenopause and help restore homeostasis.

All postmenopausal women, during sample collected period, who meet the inclusion criteria will be enrolled as research subjects. Initially, vaginal swabs and venous blood samples will be collected to assess the bacterial vaginosis condition and hematological profiles. Once bacterial vaginosis is diagnosed, subjects will receive standard antibiotic therapy, metronidazole oral 400-500 mg twice daily or 0,75% metronidazole gel 5 grams intravaginally once daily for 5 days. 48 hours after antibiotic administration, participants will be randomly divided into two groups: the treatment group, receiving Floragyn® probiotics, and the placebo group, receiving Cal95®. Probiotic or placebo treatment will be administered orally once daily for two weeks. A healthy control group will also be included for comparison and will receive Floragyn® for two weeks.

Four weeks after the last probiotic dose, vaginal swabs and venous blood samples will be collected. The analysis will include pH, glucose, protein levels, and microbiome composition from the vaginal swabs, while venous blood samples will be analyzed for interleukin 6 and 10 levels, as well as inflammatory markers such as platelets, leukocytes, and differential leukocyte counts. The collected data will be analyzed to evaluate microbiome alterations and inflammatory markers in the treatment and placebo groups.