Are statins beneficial to vaginal flora?
In the vaginal microbiota, the use of statins is associated with both a decrease in Gardnerella vaginalis and an increase in Lactobacillus: changes that consitute protective factors against the risk of bacterial vaginosis.
A direct correlation exists between the composition of the vaginal microbiota and bacterial vaginosis that is characterized, among others, by a dysbiosis of the vaginal microbiota. The vaginal flora is then more diverse, impoverished in Lactobacillus (normally the dominant species) and often rich in Gardnerella vaginalis (CST IV type microbiota). The latter forms a biofilm and secretes a toxin (vaginolysin), which lyses vaginal cells by creating pores after binding to membrane cholesterol. Studies have shown that if the level of membrane cholesterol is too low, it limits this toxin’s action. Statins reduce serum LDL cholesterol, but they also reduce the levels of membrane cholesterol. Furthermore, according to other data, statins reduce the risk of certain infections. American researchers hypothesized that the use of statins might change the composition of the vaginal microbiota.
Bacterial profiles were analyzed based on vaginal samples taken from 133 women of African and European origin (participants in the VaHMP*) who were taking statins at the time of the sampling. Also included were 152 women who had high cholesterol levels but who were not taking statins, and 316 control subjects whose cholesterol levels were normal and who were not taking statins. The results indicate that women taking statins had a significantly reduced proportion of G. vaginalis compared to non-users, whether their cholesterol levels were normal or high (8.3% versus 15.6% and 16.7%, respectively). They also had less diverse microbiotas with a higher concentration of Lactobacillus, particularly L. crispatus (CST I microbiota). The differences were particularly significant in women of African origin, who present a CST IV type microbiota more often than women of European origin. Furthermore, the researchers confirmed the statin’s mode of action in vitro. They pretreated vaginal epithelial cells with simvastatin. That made them resistant to vaginolysin, but this protective effect disappeared when cholesterol was added.
* Vaginal Human Microbiome Project
Abdelmaksoud AA1 et al. Association between statin use, the vaginal microbiome, and Gardnerella vaginalis vaginolysin-mediated cytotoxicity. 1. PLoS One. 2017 Aug 28;12(8):e0183765. doi: 10.1371/journal.pone.0183765. eCollection 2017