Daily Vaginal Microbiota Fluctuations Associated with Natural Hormonal Cycle, Contraceptives, Diet, and Exercise

Abstract

<jats:title>ABSTRACT</jats:title> <jats:p>The microorganisms of the vaginal tract are critical for vaginal and reproductive health. However, the regulation of these microorganisms is not well understood. Therefore, we investigated whether different factors regulate the vaginal microbiota of healthy college-aged women (<jats:italic>n </jats:italic>=<jats:italic> </jats:italic>26) with high temporal resolution by collecting daily self-administered vaginal swabs and using 16S rRNA sequencing for bacterial identification. As expected, vaginal microbiota clustered into five predefined community state types. Vaginal microbial diversity, stability, and <jats:italic>Lactobacillus</jats:italic> abundances were associated with the menstrual cycle and hormonal contraceptive use. Vaginal microbial diversity, as measured using the Shannon index, increased during menses (<jats:italic>P</jats:italic> &lt; 0.001), while <jats:italic>Lactobacillus</jats:italic> abundances decreased (<jats:italic>P</jats:italic> = 0.01). The covariance of these microbial measures with previously established estradiol levels suggests that estrogens can regulate vaginal microbiota. Moreover, the use of hormonal contraceptives may alter the temporal dynamics of the vaginal microbiota and decrease <jats:italic>Lactobacillus</jats:italic> abundances, depending on hormonal content and release method. Interestingly, intrasample diversity was greater in participants on a vegetarian diet (<jats:italic>P</jats:italic> = 0.004) and among participants who exercised more (<jats:italic>P</jats:italic> = 0.04). These findings indicate that ovarian hormones, diet, and exercise can regulate vaginal microbial composition and stability and may impact vaginal and reproductive health.</jats:p> <jats:p><jats:bold>IMPORTANCE</jats:bold> The vaginal microbiome is a critical component of women’s sexual and reproductive health, with variations in microbial composition, particularly the loss of <jats:italic>Lactobacillus</jats:italic> species, being implicated in gynecologic and obstetric diseases. Given that the vaginal microbiome is so crucial, why do vaginal microbial profiles vary strikingly from person to person and even change over time within the same person? In the present study, which tracked the daily vaginal microbiomes of young healthy women through different lifestyles, we found that use of a locally released progestin contraceptive, a vegetarian diet, and intense exercise appear to lead to vaginal microbiome alterations and loss of <jats:italic>Lactobacillus</jats:italic> species. The impact of these vaginal microbiome changes on immediate and long-term health remain to be investigated.</jats:p>

The vaginal microbiota in the course of bacterial vaginosis treatment

“…It has previously been reported that host genetics, ethnicity, hormonal stage (e.g. menstruation cycle, menopause, pregnancy), sexual behaviour, and hygiene practices, amongst others factors, influence vaginal microbiota composition [17][18][19][20][21].…”

Determinants of Vaginal Microbiota Composition

“…Song et al longitudinally characterized the vaginal microbiota of healthy young women (Song et al, 2020 ) and showed that vaginal microbial diversity increased and Lactobacillus abundance decreased during menses. The use of hormonal contraceptives disrupted these cyclical changes, suggesting that that temporal variation correlates with the known effects of estradiol on VMB composition.…”

The Interaction Between Microorganisms, Metabolites, and Immune System in the Female Genital Tract Microenvironment

“…Others include sexual intercourse, hormonal contraception, antimicrobial agents, use of lubricants, and vaginal douching, but they have less impact than menstrual periods and cause changes in the vaginal microbiota for a shorter duration ( Gajer et al., 2012 ; Mitchell et al., 2012 ). In addition, in a few women, the vaginal CST does not change with the menstrual cycle and hormonal contraception, but further study by future researchers is needed to determine whether it is related to the metabolic function of bacteria ( Gajer et al., 2012 ; Song et al., 2020 ).…”

“…Female genital tract infections mainly include vaginitis, cervicitis, and PID ( Sherrard et al., 2018 ). The main cause is exogenous pathogen interference or endogenous dysbiosis ( Workowski and Bolan, 2015 ; Song et al., 2020 ). At present, the relevant research on infectious diseases caused by the interaction between reproductive tract microorganisms, metabolites and the host is mainly focused on BV, Chlamydia trachomatis ( C. trachomatis ), and AV ( Ceccarani et al., 2019 ).…”