Vaginosis: Advances in new therapeutic development and microbiome restoration

Abstract

Vaginosis is a condition experienced by most women at least once in their lifetime. This condition arises due to the imbalance in the microbiome of the vaginal ecosystem. Most of the pathogens of this disease are organisms which are commonly found in a normal healthy vagina. The vaginal microbiome is important as they act as a primary defence against secondary infections and Sexually transmitted diseases and infections (STDs and STIs). The vagina is mostly dominated by Lactobacillus along with other microbes including Gardnerella vaginalis, Atopobium vaginae., Prevotella spp., Mobiluncus spp., etc. Vaginal microbiome also includes Candida albicans and other species of the genus. The ratio in which these species are present varies from person to person and the dominant species decides the whether a vagina is "normal" or not. Lactobacillus dominated vagina is considered normal and if dominated by Gardnerella and such it is considered to be Bacterial vaginosis (BV) and similarly for Vulvovaginal Candidiasis (VVC). The microbiome also undergoes changes during menstrual cycles and menopausal stages. Due to the dynamic nature of this microbiome, it is tough to perfectly restore the balance. But several treatments are currently available with antibiotics like Clindamycin and derivatives of 5-nitroimidazole drugs like Metronidazole. The extensive use and the non-adherence to the treatment regimen has led to drug resistance through biofilm formation, efflux pumps, single nucleotide polymorphisms and resulting recurrent episode of vaginosis in women. Alternative medicines, preparations from plant sources, anti-microbial peptides and nano formulations are also being explored. Most of these medicines tend to focus on reducing the pathogen load rather than restoring the balance of the ecosystem. Vaginal microbiome transplant, an effort to restore the normalcy in the vaginal environment is becoming a popular treatment. In this review we discuss about the types of vaginosis, available treatments, challenges in treating the condition and the new drugs that are under investigation.

Keywords: Drug resistance; Microbiome balance; Recurrence; Restoration of microbiome; Vaginosis.