Are certain women predisposed to STIs?
Several epidemiological studies have found a correlation between bacterial vaginosis, vulvovaginal candidiasis, colonization of the vaginal microbiota by pathogenic bacteria, and sexually transmitted infections (STIs). Based on these results, a Dutch researcher6 investigated whether their vaginal microbiota predisposes certain women to acquire STIs.
About this article
A healthy vaginal microbiota is composed of various microorganisms, where lactobacilli generally predominate. However, advances in molecular biology have shown that not all lactobacilli provide the same degree of protection: Lactobacillus crispatus, for example, is associated to an anti-inflammatory profile and seems to afford protection against pathogenic germs. On the contrary, Lactobacillus iners seems to promote an imbalance of the vaginal microbiota (dysbiosis) favorable to bacterial vaginosis, similarly to pathogenic bacteria
Microbiota, vaginosis and STIs: dangerous liaisons
Vaginosis, vaginal candidiasis, colonization of the vaginal microbiota by pathogens, and STIs share many biological and behavioral factors which could explain their interrelationships. Although vaginosis and vaginal candidiasis are not STIs per se (since they can occur without intercourse), a study by Janneke Van de Wijgert showed that sexual transmission of the responsible organisms most certainly plays a role in their development. Moreover, dysbiosis and vaginosis weaken the vaginal mucosal barrier and leads to cervicovaginal inflammation, which increases the risk of HIV infection. The risk of contracting sexually transmitted infections thus depends, at least in part, on the health of the vaginal microbiota. By preserving their microbial flora, women could limit their risk of developing STI. Future research needs to focus on determining how the vaginal microbiota can expose women to a higher risk of STI, in order to better screen and treat them, especially with local probiotics.