Probiotics for vaginosis and vulvovaginal candidiasis

Experimental research indicates that the various Lactobacillus strains of probiotics are effective in treating and preventing bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) by reducing the number of harmful bacteria, maintaining the acidic microenvironment, and inhibiting the immune response to restore the vaginal microecology.

However, the benefits of probiotics do not necessarily transfer to the clinical setting for VVC, according to a review in the journal Current Opinion in Pharmacology.¹

Some studies of probiotics for treating VVC have conflicting results, perhaps due to differences in probiotic strain, delivery mechanism, and treatment schedules. The advantage of probiotics for the infection is also somewhat predicated on whether the patient has acute infection, recurrent infection, or is at increased risk for infection.

The Chinese authors noted that the food market has numerous and different pharmaceutical forms of probiotics, including capsules, tablets, pessaries, and powders.

A study published last year in PLOS Pathogens found that several new vaginal strains demonstrated superior probiotic profiles over current commercial strains when comparing 57 vaginal Lactobacillus strains from young African women to strains from commercial probiotic products for vaginal health.²

The study concluded that for the most part, Lactobacillus strains inhibited Prevotella bivia (P. bivia) more uniformly than Gardnerella vaginalis (G. vaginalis) isolates. In addition, all vaginal Lactobacillus isolates were resistant to metronidazole, but that susceptibility to clindamycin varied. Moreover, vaginal Lactobacillus strains were more prone to broad susceptibility to penicillin, amoxicillin, rifampicin and rifabutin.

The probable safety of five of the best-performing vaginal Lactobacillus strains in the study were confirmed via whole-genome-sequencing, for which antimicrobial resistance elements were mostly absent, while putative intact prophages were present in the genomes of two of the five strains.

Another study, published in Scientific Reports in January 2021, found that the Lacticaseibacillus rhamnosus TOM 22.8 strain, when isolated from the vaginal ecosystem of a healthy woman, exhibited a broad spectrum of antagonistic activity against vaginal pathogens, adhesion capacity to both the vaginal VK2/E6E7 cell line and human colorectal adenocarcinoma cells (Caco-2 cells), along with anti-inflammatory and antioxidant activities.³

The study suggests that the strain contains promising probiotic features. When administered, the oral or vaginal strain caused a significant pathogen reduction after 10 days and maintained eubiosis up to 30 days after the end of the treatment.

The authors of the review propose that other common probiotics like Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, Escherichia, and Bacillus be tested for the prevention or treatment of BV and VVC.

“Hunting for novel probiotic strains and uncovering the precise mechanism of probiotics, especially with the new concept gut–vagina axis, to maintain the homeostasis of vaginal microbiota should be a great challenge in the future,” wrote the authors.

References:

1. Han Y, Ren Q-L. Does probiotics work for bacterial vaginosis and vulvovaginal candidiasis. Curr Opin Pharmacol. Volume 61, December 2021, pages 83-90. doi:org/10.1016/j.coph.2021.09.004

2. Happel A-U, Kullin B, Gamieldien H, et al. Exploring potential of vaginal Lactobacillus isolates from South African women for enhancing treatment for bacterial vaginosis. PLoS Pathog. 2020. 16(6): e1008559. doi:org/10.1371/journal.ppat.1008559

3. Pino A, Rapisarda AMC, Vitale SG, et al. A clinical pilot study on the effect of the probiotic Lacticaseibacillus rhamnosus TOM 22.8 strain in women with vaginal dysbiosis. Sci Rep. 2021. 11, 2592. doi.org/10.1038/s41598-021-81931-z