Clinical and Personal Lubricants Impact the Growth of Vaginal Lactobacillus Species and Colonization of Vaginal Epithelial Cells: An in Vitro Study

Factors shaping vaginal microbiota long-term community dynamics in young adult women

The vaginal microbiota is known to affect women's health. Yet, there is a notable paucity of high-resolution follow-up studies lasting several months, which would be required to interrogate the long-term dynamics and associations with demographic and behavioural covariates. Here, we present a high-resolution longitudinal cohort study of 125 women, followed for a median duration of 8.6 months, with a median of 11 samples collected per woman. Using a hierarchical Bayesian Markov model, we characterised the patterns of vaginal microbiota community persistence and transition, simultaneously estimated the impact of 16 covariates and quantified individual variability among women. We showed that "optimal" (Community State Type (CST) I, II, and V) and "sub-optimal" (CST III) communities are more stable over time than "non-optimal" (CST IV) ones. Furthermore, we found that some covariates - most notably alcohol consumption - impacted the probability of shifting from one CST to another. We performed counterfactual simulations to confirm that alterations of key covariates, such as alcohol consumption, could shape the prevalence of different microbiota communities in the population. Finally, our analyses indicated that there is a relatively canalised pathway leading to the deterioration of vaginal microbiota communities, whereas the paths to recovery can be highly individualised among women. In addition to providing one of the first insights into vaginal microbiota dynamics over a year, our study showcases a novel application of a hierarchical Bayesian Markov model to clinical cohort data with many covariates. Our findings pave the way for an improved mechanistic understanding of microbial dynamics in the vaginal environment and the development of novel preventative and therapeutic strategies to improve vaginal health.

Assessment of the vaginal microbiota before and after use of hyperosmolal lubricant during transvaginal ultrasound

BACKGROUND

Vaginal lubricants are commonly used during sexual activity and clinical procedures such as transvaginal ultrasound. Epidemiologic and laboratory studies indicate hyperosmolal water-based lubricants may disrupt the vaginal microbiota, particularly the beneficial Lactobacillus spp. These bacteria play a critical role in protecting against sexually transmitted infection acquisition and other adverse gynecologic and obstetric outcomes.

OBJECTIVE

We sought to evaluate changes in the composition of the vaginal microbiota before and after a single exposure to lubricant over a 10-week period among pre-, peri-, and postmenopausal patients referred for transvaginal ultrasound.

STUDY DESIGN

One hundred four participants self-collected mid-vaginal swabs daily between baseline and transvaginal ultrasound (∼1 week), immediately before transvaginal ultrasound ("pre-transvaginal ultrasound"), and 6 to 12 hours after transvaginal ultrasound ("post-transvaginal ultrasound"). Participants attended a follow-up visit ∼2 to 5 days after transvaginal ultrasound ("post-transvaginal ultrasound follow-up"), continued to self-sample twice-weekly for 9 weeks, and attended a final clinical visit in week 10. Microbiota composition was characterized by 16S ribosomal RNA gene amplicon sequencing (V3-V4) and assigned to community state types (low-Lactobacillus vs Lactobacillus-dominated). Yue-Clayton theta indices defined similarity between daily successive samples between baseline and transvaginal ultrasound and overall stability of the vaginal microbiota before and after transvaginal ultrasound. Analysis of Compositions of Microbiomes II determined differentially abundant taxa in post-transvaginal ultrasound samples vs pre-transvaginal ultrasound samples. Generalized linear mixed models evaluated the odds of having a low-Lactobacillus microbiota after transvaginal ultrasound with samples before transvaginal ultrasound as the reference for each participant.

RESULTS

A majority of the cohort was premenopausal (85/104, 82%) and self-reported Black race (65/104, 62%). Over the short-term (1 week), there was no immediate changes in the composition of the microbiota of daily successive samples following transvaginal ultrasound. In contrast, over the longer-term (participants followed for 10 weeks), the vaginal microbiota was less stable within intervals after transvaginal ultrasound vs the interval before. There were no changes in the odds of a low-Lactobacillus microbiota after transvaginal ultrasound among all participants in this 10-week longitudinal study. However, in specific groups such as peri/postmenopausal participants (N=19, adjusted odds ratio: 3.22, 95% confidence interval:1.16-8.98) and those with a history of bacterial vaginosis (N=58, adjusted odds ratio: 1.73, 95% confidence interval:1.10-2.72), there was a higher likelihood of persisting in a low-Lactobacillus state throughout the follow-up period.

CONCLUSION

Peri- and postmenopausal individuals and those with a history of bacterial vaginosis show a sustained decrease in protective Lactobacillus spp. after a single exposure to hyperosmolal vaginal lubricant. Reformulating water-based lubricants to reduce osmolality and toxicity may be beneficial.

Vaginal irritation testing-prospects of human organotypic vaginal tissue culture models

Personal lubricants intended for local or systemic delivery via the vaginal route can induce vaginal irritation, damage the vaginal epithelial barrier which can enhance microbial entry, induce inflammation, and alter the microbiome of the vaginal ecosystem. Therefore, manufacturers of personal lubricants and medical devices are required to show biocompatibility and safety assessment data to support regulatory decision-making within a specified context of use. Furthermore, due to ethical concerns and the introduction of the 7th amendment of the European Council Directive which bans animal testing for cosmetic ingredients and products coupled with the Food and Drug Administration modernization Act 2.0 guidelines, there is a wave of drive to develop alternative test methods to predict human responses to chemical or formulation exposure. In this framework, there is a potential to use three-dimensional organotypic human vaginal-ectocervical tissue models as a screening tool to predict the vaginal irritation potential of personal lubricants and medicaments. To be physiologically relevant, the in vitro tissue models need to be reconstructed using primary epithelial cells of the specific organ or tissue and produce organ-like structure and functionality that recapitulate the in vivo-like responses. Through the years, progress has been made and vaginal tissue models are manufactured under controlled conditions with a specified performance criterion, which leads to a high level of reproducibility and reliability. The utility of vaginal tissue models has been accelerated in the last 20 years with an expanded portfolio of applications ranging from toxicity, inflammation, infection to drug safety, and efficacy studies. This article provides an overview of the state of the art of diversified applications of reconstructed vaginal tissue models and highlights their utility as a tool to predict vaginal irritation potential of feminine care products.

Inferring stability and persistence in the vaginal microbiome: A stochastic model of ecological dynamics

The interplay of stochastic and ecological processes that govern the establishment and persistence of host-associated microbial communities is not well understood. Here we illustrate the conceptual and practical advantages of fitting stochastic population dynamics models to multi-species bacterial time series data. We show how the stability properties, fluctuation regimes and persistence probabilities of human vaginal microbial communities can be better understood by explicitly accommodating three sources of variability in ecological stochastic models of multi-species abundances: 1) stochastic biotic and abiotic forces, 2) ecological feedback and 3) sampling error. Rooting our modeling tool in stochastic population dynamics modeling theory was key to apply standardized measures of a community's reaction to environmental variation that ultimately depends on the nature and intensity of the intra-specific and inter-specific interaction strengths. Using estimates of model parameters, we developed a Risk Prediction Monitoring (RPM) tool that estimates temporal changes in persistence probabilities for any bacterial group of interest. This method mirrors approaches that are often used in conservation biology in which a measure of extinction risks is periodically updated with any change in a population or community. Additionally, we show how to use estimates of interaction strengths and persistence probabilities to formulate hypotheses regarding the molecular mechanisms and genetic composition that underpin different types of interactions. Instead of seeking a definition of "dysbiosis" we propose to translate concepts of theoretical ecology and conservation biology methods into practical approaches for the management of human-associated bacterial communities.

Investigating the impact of condomless vaginal intercourse and lubricant use on the vaginal metabolome: a pre-post observational study

OBJECTIVE

The vaginal metabolome is a significant factor in the vaginal microenvironment, and data are emerging on its independent role in urogenital health. Condomless vaginal intercourse and personal lubricant use are common practices that may affect the vaginal metabolome. The aim of the present study is to describe the associations between condomless intercourse and lubricant use on the vaginal metabolome.

METHODS

This study used archived mid-vaginal swabs from a 10-week observational cohort of reproductive age women who self-collected samples and recorded behavioural diaries daily. Cases and controls were defined as participants who self-reported condomless vaginal intercourse with or without lubricant use, respectively. Samples were drawn prior to and following condomless vaginal intercourse. Twenty-two case participants were race/ethnicity matched to 22 control participants. Mid-vaginal swabs were subjected to 16S rRNA gene amplicon sequencing and untargeted ultrahigh performance liquid chromatography tandem mass spectroscopy metabolomics. Bayesian mixed-effects regression (unadjusted and adjusted for the vaginal microbiota) was used to evaluate differences in metabolite concentration associated with vaginal intercourse and lubricant use.

RESULTS

Both condomless penile-vaginal intercourse and lubricant use were independently associated with higher (up to 8.3-fold) concentrations of metabolites indicative of epithelial damage (eg, sarcosine) and many host-produced antioxidants. Lubricant use was significantly associated with increases in lipids related to cellular damage, host-produced sphingolipids (antimicrobials), antioxidants and salicylate, a cooling agent common to lubricants, in a study design which controls for the independent effect of intercourse. Metabolites involved in oxidative stress and salicylate were strongly correlated with several molecular bacterial vaginosis-associated bacteria.

CONCLUSIONS

This study provides important foundational data on how condomless vaginal-penile intercourse and lubricant use affect the vaginal metabolome and may affect the protective mechanisms in the vaginal microenvironment.

Gynecological concerns and vaginal practices and exposures among transfeminine individuals who have undergone vaginoplasty

BACKGROUND

Vaginoplasty is a gender-affirming surgery that is medically necessary for some transfeminine individuals. Little research exists describing vaginal health after the initial recovery from surgery, and evidence-based guidelines for vaginal care practices are unavailable.

AIM

The study sought to describe self-reported gynecological concerns and vaginal care practices among transfeminine persons who have undergone vaginoplasty.

METHODS

A total of 60 transfeminine participants 18+ years of age, living in Canada, and who had undergone vaginoplasty at least 1 year prior were recruited through social media, community groups, healthcare provider referrals, and study recontact. Participants completed a cross-sectional, online questionnaire detailing demographics, gynecological concerns, and genital practices and exposures. Hierarchical clustering was used to group participants based on behavioral practices and exposures. Associations between clusters and gynecological concerns were assessed.

OUTCOMES

Outcomes included self-reported gynecological concerns within the past year, recent vulvar or vaginal symptoms (past 30 days), and behavioral practices/exposures, including douching with varied products and dilating.

RESULTS

Participants reported a variety of concerns in the past year, including urinary tract infection (13%) and internal hair regrowth (23%). More than half (57%) had experienced at least 1 recent vaginal symptom, most commonly malodor (27%) and vaginal bleeding (21%). Of participants, 48% were dilating weekly and 52% reported douching in the past 30 days. Four distinct clusters of vaginal practices/exposures were identified: limited exposures; dilating, no douching; dilating and douching; and diverse exposures. No significant associations between cluster membership and gynecological concerns were identified, though cluster membership was significantly associated with surgical center (P = .03). Open-text write-ins provided descriptions of symptoms and symptom management strategies.

CLINICAL IMPLICATIONS

The results provide insight for clinicians on common patient-reported gynecological concerns and current vaginal care practices and exposures, including symptom management strategies.

STRENGTHS AND LIMITATIONS

This was the first study to investigate vaginal health and genital practices/exposures among a community sample of transfeminine individuals. As participants self-enrolled for a detailed survey and swab collection, individuals experiencing concerns were likely overrepresented.

CONCLUSION

Transfeminine individuals reported a range of gynecological concerns outside of the surgical healing period. Genital practices/exposures varied across clusters, but no clear associations between clusters and symptoms were identified; instead, practice/exposure clusters were dependent on where the individual underwent vaginoplasty. There is a need for evidence to inform diagnostics, treatments, and vaginal care guidelines to support vaginal health.

A qualitative exploration of internet forum discussions surrounding female sexual function for individuals with Sjögren's syndrome

Sexual dysfunction is a common experience for women with the autoimmune rheumatic disease, Sjögren's syndrome (SS); however, the lived experience of how the disease affects sexual functioning and the sexual environment remains unexplored. This qualitative study explores the conversations pertaining to female sexual function and the sexual environment that individuals with SS have on an internet forum. Qualitative data posted on one publicly accessible, worldwide, internet forum was extracted using an automated web scraping tool. A total of 247,694 posts across 23,382 threads were scraped from the forum in July 2019 and June 2022 (from the United Kingdom). A predetermined and theoretically informed keyword search strategy was used to screen the captured data for content relevant to the study aim. The dataset was cleaned to remove duplication and identifying information and screened for topic relevance. The Computer-Assisted Qualitative Data Analysis software tool, ATLAS.ti, was used to facilitate the data analysis process. Thematic analysis was conducted on 1443 female-oriented posts, and four key themes were identified: the symptoms of SS and their impact on the sexual environment; the emotional responses that are commonly evoked in response to sexual difficulties; the strategies that users have implemented to manage sexual problems; and the impact that a partner's behavior may have on the sexual environment. Together these themes provide an insight into the nature of sexual difficulties for females with SS. Our findings provide novel insights to inform clinical discussions between practitioners and patients whilst further outlining the importance of undertaking qualitative research with this population.

The role of microbiota in the management of genitourinary syndrome of menopause

It is estimated that the 25-50% of women who are reaching menopause every year report symptoms related to the genitourinary syndrome of menopause (GSM). The symptoms are not due simply to lack of estrogen. One possible contributing cause of symptoms is the vaginal microbiota. The vaginal microbiota is a dynamic entity and plays a critical role in the pathogenic interplay of postmenopausal changes. Treatment of this syndrome depends on the severity and type of the symptoms and on the preferences and expectations of women. As there are many treatment options, therapy should be individualized. While new evidence on the role of Lactobacilli in premenopause is emerging, the role of Lactobacilli is still unclear in GSM and the impact of microbiota on vaginal health remains conflictual. However, some reports show promising data on the effect of probiotic therapy in menopause. In the literature there are few studies and small population samples on the role of an exclusive therapy with Lactobacilli and further data will be mandatory. Studies involving large numbers of patients and different intervention periods will be necessary to obtain evidence of the preventive and curative role of vaginal probiotics.

A randomized trial on the effectiveness and safety of 5 water-based personal lubricants

BACKGROUND

A range of personal lubricants with different formulations and subsequent properties are available for relief of discomfort associated with vaginal dryness; however, there are limited clinical data to support the efficacy and safety of many commercially available lubricants.

AIM

To determine the effectiveness and safety of 5 water-based personal lubricants for the relief of intimate discomfort associated with vaginal dryness in pre- and postmenopausal women: 4 that were formulated to meet the World Health Organization (WHO) guidelines for osmolality and pH and 1 preexisting lubricant of higher osmolality and pH.

METHODS

An open-label, parallel-design study was performed in women aged 18 to 65 years with mild-to-moderate vaginal dryness and dyspareunia. Participants were randomized to 1 of 5 lubricants (A-E) from 3 brands (Durex, KY, Queen V). They were instructed to use their allocated lubricants during vaginal intercourse at least once a week over a 4-week period. The Female Sexual Function Index (FSFI) measured sexual functioning after 4 weeks of use as an indicator of lubricant performance.

OUTCOMES

The primary outcome was change from baseline in total FSFI score after 4 weeks of product use.

RESULTS

A total of 174 women completed the study. The primary end point-a prespecified increase in FSFI ≥4 points from baseline after 4 weeks of use-was met by all 5 lubricants tested. A statistically significant improvement was observed across all 6 domains of the FSFI from baseline to 4 weeks of use with all 5 lubricants (P < .0001 for lubrication and pain reduction and P < .05 for all other domains). No serious adverse events occurred in the study, and the tolerance of all 5 lubricants was good/very good.

CLINICAL IMPLICATIONS

The efficacy and safety of the tested lubricants are not compromised when formulated to meet the WHO criterion of osmolality ≤1200 mOsm/kg. The lubricants tested in this investigation can be used not only to relieve symptomatology of vaginal dryness and dyspareunia but also to enhance overall sexual satisfaction.

STRENGTHS AND LIMITATIONS

This study provides clinical evidence for the efficacy and safety of 5 lubricants, including those formulated to meet WHO guidelines, in relieving symptoms of vaginal dryness and improving the overall sexual experience. The open-label design may have introduced bias into the study.

CONCLUSION

All 5 lubricants, including those formulated to be compliant with guidelines on pH and osmolality, can be considered effective and well tolerated for the relief of discomfort associated with vaginal dryness.

Connecting microbiome and menopause for healthy ageing

Understanding the interplay between the microbiome and menopause holds promise for new interventions to alleviate menopausal symptoms and improve quality of life for women.

Impact of vaginal douching products on vaginal Lactobacillus, Escherichia coli and epithelial immune responses

We compared the effect of commercial vaginal douching products on Lactobacillus crispatus, L. jensenii, L. gasseri, L. iners, E. coli, and immortalized vaginal epithelial cells (VK2). All studied douching products (vinegar, iodine and baking soda based) induced epithelial cell death, and all inhibited growth of E. coli. Co-culture of vaginal epithelial cells with any of the lactobacilli immediately following exposure to douching products resulted in a trend to less human cell death. However, co-culture of epithelial cells with L. iners was associated with higher production of IL6 and IL8, and lower IL1RA regardless of presence or type of douching solution. Co-culture with L. crispatus or L. jensenii decreased IL6 production in the absence of douches, but increased IL6 production after exposure to vinegar. Douching products may be associated with epithelial disruption and inflammation, and may reduce the anti-inflammatory effects of beneficial lactobacilli.

Vaginal cytokine profile and microbiota before and after lubricant use compared with condomless vaginal sex: a preliminary observational study

BACKGROUND

Limited data suggest that personal lubricants may damage the vaginal mucosal epithelium, alter the vaginal microbiota, and increase inflammation. We compared vaginal cytokine profiles and microbiota before and after vaginal lubricant use and condomless vaginal sex.

METHODS

Reproductive-age women were recruited to a 10-week observational cohort study and were asked to self-collect vaginal samples and behavioral diaries daily. This nested case-control analysis utilized samples collected before and after self-reported condomless sexual activity with lubricants (22 case participants) and without lubricants (22 control participants). Controls were matched to cases on race/ethnicity. Microbiota composition was characterized by sequencing amplicons of the 16S rRNA gene V3-V4 regions. Cytokine concentrations were quantified using a magnetic bead 41-plex panel assay and read using a Bio-Plex 200 array reader. Wilcoxon signed-rank tests were used to assess baseline differences in vaginal cytokines between cases and controls as well as differences pre- and post-exposure. Linear mixed effects models were used to examine differences in relative post-to-pre change in each individual cytokine between matched cases and controls. Similar analyses were conducted for the microbiota data.

RESULTS

Mean age was 29.8 years (SD 6.8), and 63.6% were African American. There were few statistically significant changes in cytokines or microbiota before and after exposure in cases or controls. In mixed-effects modeling, the mean relative post-to-pre change of cytokines was higher in cases vs. controls for macrophage derived chemokine (MDC) (p = 0.03). The microbiota data revealed no significant changes when measured by similarity scores, diversity indexes and descriptive community state types (CST) transition analyses. However, post sexual activity, the mean relative abundance of L. crispatus decreased for those who used lubricants (particularly those who were L. iners-dominated prior to exposure).

CONCLUSIONS

Although there were overall few differences in the vaginal microbiota and cytokine profiles of lubricant users and controls before and after condomless vaginal sex, there was a trend toward decreases in relative abundance of L. crispatus following use of lubricant. Future larger studies that take into account osmolarity and composition of lubricants may provide additional insights.

Association of Vaginal Microbiota with Signs and Symptoms of the Genitourinary Syndrome of Menopause across Reproductive Stages

The genitourinary syndrome of menopause (GSM) describes signs and symptoms resulting from effects of estrogen deficiency on the female genitourinary tract, including the vagina, labia, urethra, and bladder. Signs/symptoms associated with GSM may occur during any reproductive stage from multiple etiologies but are most common during menopause due to low estrogen. Vaginal microbiota, particularly Lactobacillus spp., are beneficial to the female genital tract; however, their abundance declines during menopause. We aimed to longitudinally assess vaginal microbiota characterized by 16S rRNA gene amplicon sequencing and GSM-associated endpoints across reproductive stages. In a two-year cohort study of 750 women aged 35-60 years at enrollment and 2,111 semiannual person-visits, low-Lactobacillus vaginal microbiota communities were observed at 21.2% (169/798), 22.9% (137/597), and 49.7% (356/716) of person-visits among pre-, peri-, and postmenopausal women, respectively (p<.001). Compared to communities that have high Gardnerella vaginalis relative abundance and diverse anaerobes, the following communities were associated with a lower covariate-adjusted odds of vaginal atrophy: L. crispatus-dominated communities among postmenopausal women (odds ratio[OR]=0.25; 95% confidence interval[CI], 0.08, 0.81), L. gasseri/L. jensenii (OR=0.21; 95%CI, 0.05, 0.94) and L. iners (OR=0.21; 95%CI, 0.05, 0.85) among perimenopausal women, and L. iners-dominated communities (OR=0.18; 95%CI, 0.04, 0.76) among premenopausal women. Postmenopausal women with L. gasseri/L. jensenii-dominated communities had the lowest odds of vaginal dryness (OR=0.36; 95%CI, 0.12, 1.06) and low libido (OR=0.28; 95%CI, 0.10, 0.74). Findings for urinary incontinence were inconsistent. Associations of vaginal microbiota with GSM signs/symptoms are most evident after menopause, suggesting an avenue for treatment and prevention.