Effect of 17\u03b2-estradiol on a human vaginal Lactobacillus crispatus strain

Maximilien Clabaut,Ali Tahrioui,Madina Karsybayeva,Pierre-Jean Racine,Gérard Redziniak,Julien Verdon,Olivier Maillot,Marc G J Feuilloley,Magalie Barreau,Coralie Kremser,Chantal Pichon,Sylvie Chevalier,Cécile Duclairoir-Poc,Agathe Le Tirant,Amandine Suet

doi:10.1038/s41598-021-86628-x

Abstract

Lactobacilli and estrogens play essential roles in vaginal homeostasis. We investigated the potential direct effect of 17β-estradiol on a vaginal strain of Lactobacillus crispatus, the major bacterial species of the vaginal microbiota. 17β-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 17β-estradiol, but its mean size was significantly reduced. 17β-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 17β-estradiol binding site. Overall, our results reveal direct effects of 17β-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.

Highlights

Lactobacilli and estrogens play essential roles in vaginal homeostasis
We investigated the effects of estradiol on a vaginal strain of L. crispatus, the genome of which was recently s equenced[34], through cell-binding assays and physiological, physicochemical, morphological, and bioinformatics approaches
There is ample evidence that the response of human commensal bacteria to peptide hormones and neurohormones is essential for skin h omeostasis[45]

Summary

Introduction

Lactobacilli and estrogens play essential roles in vaginal homeostasis. We investigated the potential direct effect of 17β-estradiol on a vaginal strain of Lactobacillus crispatus, the major bacterial species of the vaginal microbiota. 17β-estradiol (10–6 to 10–10 M) had no effect on L. crispatus growth, but markedly affected the membrane dynamics of this bacterium. Our results reveal direct effects of 17β-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. The composition of the post-menopause vaginal microbiota gradually comes to resemble that of the cutaneous microbiota These events are frequently associated with gynecological problems, including itching, inflammation, and even infections[13], because lactobacilli naturally provide protection against pathogens. This protection results from the extensive secretory activity of lactobacilli, which produce the lactic acid responsible for the decrease in vaginal pH and key protection factor[14, 15], and hydrogen p eroxide[8, 16], exoenzymes, bacteriocins and surfactants[17,18,19]. We found that estradiol can affect the physiology of lactobacilli, suggesting a possible key role for estradiol in their adherence to the vaginal mucosa

Methods

Results

Conclusion