S13.4 The vaginal microbiome and sti

Abstract

Our systematic review of 63 molecular vaginal microbiome (VMB) studies conducted between 2008 and 2013 confirmed that lactobacilli-dominated VMB are associated with a healthy vaginal micro-environment and that bacterial vaginosis (BV) is best described as a polybacterial dysbiosis. However, not all lactobacilli seem to be equally healthy (e.g. a Lactobacillus inersdominated VMB is more likely to shift to dysbiosis than an L. crispatus-dominated VMB and L. iners often remains present during dysbiosis) and multiple dysbiosis entities with clinical relevance seem to exist. Some women with BV have a highly diverse VMB consisting of high loads of planktonic anaerobic bacteria, while others have a vaginal biofilm (typically including Gardnerella vaginalis). Furthermore, a small but clinically relevant proportion of women have a VMB dominated by Streptococci and/or Escherichia coli. Vaginal colonisation with Candida spp. is more common in women with a lactobacilli-dominated VMB than in women with dysbiosis, and women who receive antibiotic treatment for BV often subsequently develop vaginal candidiasis. Research has shown that all of these conditions cause disruption of the cervicovaginal mucosal barrier as well as cervicovaginal inflammation, which in turn might cause serious complications such as increased HIV acquisition, pre-term birth, and maternal/neonatal sepsis. At the moment, asymptomatic BV (by microscopic and clinical criteria) is usually not treated and symptomatic BV is treated with oral or vaginal metronidazole or clindamycine. However, recurrence rates are very high (up to 50% within six months) and novel treatments - such as vaginal biofilm disruption and vaginal probiotics - are therefore needed. Furthermore, the different dysbiosis entities, or combinations of entities, likely require different clinical management approaches. Systems biology has now become more affordable and should be incorporated into epidemiological studies to address associations of different dysbiotic entities with clinical outcomes, and to evaluate interventions aimed at restoring and maintaining a lactobacilli- dominated VMB.