Effect of 17β-estradiol on a human vaginal Lactobacillus crispatus strain

Lactobacilli and estrogens play essential roles in vaginal homeostasis. We investigated the potential direct effect of 17 beta-estradiol on a vaginal strain of Lactobacillus crispatus, the major bacterial species of the vaginal microbiota. 17 beta-estradiol (10(-6) to 10(-10) M) had no effect on L. crispatus growth, but markedly affected the membrane dynamics of this bacterium. This effect appeared consistent with a signal transduction process. The surface polarity and aggregation potential of the bacterium were unaffected by exposure to 17 beta-estradiol, but its mean size was significantly reduced. 17 beta-estradiol also promoted biosurfactant production by L. crispatus and adhesion to vaginal VK2/E6E7 cells, but had little effect on bacterial biofilm formation activity. Bioinformatic analysis of L. crispatus identified a membrane lipid raft-associated stomatin/prohibitin/flotillin/HflK domain containing protein as a potential 17 beta-estradiol binding site. Overall, our results reveal direct effects of 17 beta-estradiol on L. crispatus. These effects are of potential importance in the physiology of the vaginal environment, through the promotion of lactobacillus adhesion to the mucosa and protection against pathogens.

Automated summary

Research shows that 17 beta-estradiol has direct effects on Lactobacillus crispatus, affecting membrane dynamics and promoting biosurfactant production and adhesion to vaginal cells. These effects are important for the physiology of the vaginal environment, contributing to lactobacillus adhesion to mucosa and protection against pathogens.