A Pilot Study to Evaluate the Efficacy and Safety of Lactobacillus Species Suppositories on Vaginal Health and pH

Overview

Most of the methods involved in the treatment of BV include antibiotics. Some of the antibiotics used for this include metronidazole, clindamycin and fluconazole. The antibiotics inhibit the growth of anaerobes that support G. vaginalis and other microbes without affecting lactobacilli. This leads to the treatment of BV while also preventing its recurrence. However, the use of antibiotics may lead to antibiotic resistance and cause various side-effects such as thrush, dizziness, rash, nausea, etc. In the case of many antibiotics, the cure rates were incredibly poor and the BV recurrence rates reached as high as 80 %. Probiotic therapy has slowly been replacing antibiotics for the treatment and prevention of BV and other infections. These probiotics usually contain lactobacilli and help maintain a healthy vaginal environment. They can either be consumed through curd and other milk products that contain probiotics (mostly lactobacilli) or they can be used in the form of suppositories that are placed in the vagina. In probiotics containing lactobacilli, the lactic acid produced by the bacteria lowers the vaginal pH to the ideal range of 3.5 to 4.5 and prevents infection recurrence. Lactobacilli containing suppositories have been successfully used in the past to treat BV, being marketed as a safe and effective way to prevent and treat infections for women in various stages of their lives.

The vaginal microbiome is said to be the first line of defence against vaginal infection, due to competitive exclusion and the destruction of pathogenic microbes. The vagina remains relatively sterile until a woman reaches puberty, after which the hormonal changes cause the colonization of lactobacilli in the vaginal environment. Any alterations in the microbiota are seen to cause symptomatic conditions. These conditions may include bacterial vaginosis (BV), vaginal candidiasis and trichomoniasis. The reduction in circulating hormone levels in older women as they near menopause triggers various physiological changes in the vagina. Vulvovaginal atrophy, dryness, itchiness, redness, loss of elasticity, inflammation and atypical secretions are some of the changes that occur in the vagina as estrogen and progesterone levels decrease in the blood. The aforementioned reduction in hormone levels would also lead to a decline in the concentration of lactobacilli in the vaginal environment. The lactobacilli produce lactic acid, which creates an acidic vaginal environment conducive to the growth of lactobacilli, while preventing the growth of other anaerobic bacterial species. The dominant lactobacilli also prevent the binding of other bacteria to the epithelial cells and the lactic acid produced by lactobacilli blocks histone deacetylases, thereby enhancing gene transcription and DNA repair within their cells. Moreover, the lactobacilli also inhibit the induction of pro-inflammatory cytokines while promoting homeostasis. Some of the species from the Lactobacilli genus that have been identified as residents of the vaginal environment include L. crispatus, L. gasseri, L. iners, and L. jensenii Therefore, it is seen that women who experience lowering of hormone levels i.e. as they approach menopause, the chances of contracting vaginal infection increases due to the lower concentrations of lactobacilli. Bacteria such as Gardnerella, Atopobium, Mobiluncus, Prevotella, Streptococcus, Ureaplasma and Megasphaera, which were previously left dormant due to the lactobacilli, may increase in concentration and increase the susceptibility of these women to contract infections such as bacterial vaginosis. Bacterial vaginosis is usually caused by the overabundance of G. vaginalis and other anaerobes, and can be clinically diagnosed using the Amsel criteria. This technique requires at least three positive findings of the four diagnostic criteria: a fishy odor after a 10% potassium hydroxide test for vaginal secretion, the presence of non-inflammatory vaginal discharge, clue cells on microscopic examination, and vaginal fluid pH \> 4.5. The nugent score is also a well-validated technique to diagnose BV. In this study, the safety and efficacy of the vaginal suppository VagiBIOM will be studied in aging women with BV infection. The effect of the suppository on vaginal pH and the physiological changes in the vagina will be examined, along with its impact on vaginal infection.