Sexual practices have a significant impact on the vaginal microbiota of women who have sex with women

Unravelling the vaginal microbiome, impact on health and disease

PURPOSE OF REVIEW

The vaginal microbiome has a fundamental role in supporting optimal vaginal, reproductive, and sexual health. Conversely, dysbiosis of the vaginal microbiome is linked to vaginal symptoms and adverse health outcomes. This review summarizes recent literature concerning the role of the vaginal microbiome in health and disease, with a focus on the most common vaginal dysbiosis, bacterial vaginosis.

RECENT FINDINGS

Molecular studies have expanded our understanding of the composition of the vaginal microbiome. Lactic acid-producing lactobacilli are an important component of host defences against pathogens, whereas a paucity of lactobacilli is associated with adverse sequelae. Bacterial vaginosis is characterized by low levels of lactobacilli and increased levels of nonoptimal anaerobes; however, the exact cause remains unclear. Furthermore, despite decades of research, bacterial vaginosis recurrence rates following standard treatment are unacceptably high. Strategies to improve bacterial vaginosis cure and promote an optimal lactobacilli-dominated vaginal microbiome are being investigated. Importantly, historical and emerging evidence supports the sexual transmission of bacterial vaginosis, which opens exciting opportunities for novel treatments that incorporate partners.

SUMMARY

A mechanistic and deeper understanding of the vaginal microbiome in health and disease is needed to inform ongoing development of therapeutics to improve bacterial vaginosis cure. Partner treatment holds promise for improving bacterial vaginosis cure.

The association between lifestyle factors and the composition of the vaginal microbiota: a review

PURPOSE

The vaginal microbiota offers valuable insights into women's sexual health and the risk of developing sexually transmitted infections (STIs) and bacterial vaginosis. Despite the public health implications of changes in the vaginal environment, existing data on this topic remain sparse.

METHODS

Following the PRISMA statement guidelines, we consulted five bibliographic databases, focusing on five main daily habits and behaviors. We included only studies published up to October 2023, investigating the influence of personal hygiene, sexual behaviors, hormonal contraception, smoking, alcohol consumption, and psychosocial stress on the vaginal microbiota using next-generation sequencing.

RESULTS

Based on our inclusion criteria, we incorporated 37 studies into this review. Hormonal contraception and personal hygiene were found to promote eubiosis of the vaginal microbiota. In contrast, sexual behaviors, smoking, alcohol consumption, and psychosocial stress were associated with an increased susceptibility to bacterial vaginosis, STIs, and severe pelvic inflammatory diseases due to a modified vaginal microbiota. Black ethnicity emerged as a confounding factor, with this population showing unstable vaginal microbiota. Oral contraception and a stable male sexual partner were found to favor Lactobacillus colonization, acting as a protective factor. Conversely, non-hormonal contraception and unprotected or non-penile/vaginal sexual activity increased the incidence of vaginal inflammation and bacterial vaginosis by disturbing the vaginal microbiota and reducing Lactobacillus abundance.

CONCLUSION

Daily habits and lifestyle can influence the composition of the vaginal microbiota, thereby affecting vaginal health. Disturbances in the vaginal microbiota could be associated factors for STIs and vaginosis. Therefore, prioritizing more appropriate management of the vaginal microbiota is crucial.

Effectiveness of vaginal probiotics Lactobacillus crispatus chen-01 in women with high-risk HPV infection: a prospective controlled pilot study

Female genital tract infection with high-risk human papilloma virus (HR-HPV) has the risk of developing into cervical cancer, and there is still a lack of effective therapeutic strategies. Probiotic intervention is considered as a potential intervention for HR-HPV, while exploration into living probiotic preparations for specific diseases remains limited and insufficient. This prospective controlled pilot study was conducted to observe the effect of intravaginal transplantation of a vaginal isolated natural probiotic strain, Lactobacillus crispatus chen-01, on the clearance of high-risk HPV infection. 100 women with high-risk HPV infection were enrolled and randomly divided into placebo group and probiotic treatment group, which received intravaginal transplantation of L. crispatus chen-01. Cervical exfoliated cells were collected 6 months later for detecting DNA load, typing of HPV, and cytological analysis. Our results showed that vaginal transplantation with L. crispatus chen-01 significantly reduced viral load of HPV, ameliorated HPV clearance rate, and improved vaginal inflammation state without causing obvious adverse reactions. Analysis of 16S rRNA sequencing revealed that L. crispatus chen-01 could effectively reconstitute the vaginal microbiota in women with high-risk HPV, which might be one of the underlying mechanisms of the beneficial effect of L. crispatus chen-01 transplantation. Our results suggested that vaginal transplantation of L. crispatus chen-01 might be a promising treatment for patients with high-risk HPV infection.

An updated study of the relationship between bacterial infections and women's immune system, focusing on bacterial compositions with successful pregnancy

Genital tract infections can cause a variety of harmful health outcomes, including endometritis, bacterial vaginosis, and pelvic inflammatory disease, in addition to infertility. Anaerobic bacteria, such as Gardnerella vaginalis, Megasphaera spp., and Atopobium vaginae, are more commonly identified in cases of bacterial vaginosis than lactobacilli. It is unknown how the microorganisms that cause pelvic inflammatory diseases and endometritis enter the uterus. Both prospective and retrospective research have connected pelvic inflammatory disorders, chronic endometritis, and bacterial vaginosis to infertility. Similar to bacterial vaginosis, endometritis-related infertility is probably caused by a variety of factors, such as inflammation, immune system recognition of sperm antigens, bacterial toxins, and a higher risk of STDs. Preconception care for symptomatic women may include diagnosing and treating pelvic inflammatory disease, chronic endometritis, and bacterial vaginosis before conception to optimize the results of both natural and assisted reproduction.

Relationship between Bacterial Vaginosis and Sexually Transmitted Infections: Coincidence, Consequence or Co-Transmission?

Sexually transmitted infections (STIs) are a serious global problem, causing disease, suffering, and death. Although bacterial vaginosis (BV) is not considered to be an STI, it may be associated with an increased risk of contracting a wide range of STIs. We sought to assess the link between the different microorganisms involved in STIs and BV. A total of 290 vaginal swabs from 290 women sent for diagnostic purposes to the clinical microbiology laboratory of the Marseille University Public Hospitals were tested by specific qPCR targeting STI-causing microorganisms and BV. Of these 290 swabs, 15.2% (44/290) were diagnosed with at least one STI-causing microorganism and 17.2% (50/290) with BV. The prevalence of STIs was significantly higher in women with BV (28%, 14/50) than in those without (20.4%, 51/240). The prevalence of co-infections involving two STI-causing microorganisms was significantly more frequent in women with BV than in those without (18% [8/50] vs. 2% [5/250]; p < 0.001). The prevalence of monoinfections and polyinfections with STI-causing microorganisms was lower in women without BV than in those with (8.8% [21/240] vs. 28% [14/50]), p < 0.001 and 2% (5/240) vs. 8% (4/50), p = 0.05, respectively). Our data suggest that a correlation between BV and STI may exist, with a higher prevalence of both monoinfections and polyinfections involving STI-causing microorganisms in women with BV. Further research is needed to better understand BV and its links to STIs.

The Impact of the Female Genital Microbiota on the Outcome of Assisted Reproduction Treatments

The vaginal microbiota plays a critical role in the health of the female genital tract, and its composition contributes to gynecological disorders and infertility. Lactobacilli are the dominant species in the female genital tract: their production of lactic acid, hydrogen peroxide, and bacteriocins prevents the invasion and growth of pathogenic microorganisms. Several factors such as hormonal changes, age of reproduction, sexual practices, menstrual cycle, pregnancy, and antimicrobial drugs use can cause imbalance and dysbiosis of the vaginal microbiota. This review aims to highlight the impact of the vaginal microbiota in Assisted Reproductive Technology techniques (ART) and it examines the factors that influence the vaginal microbiota, the consequences of dysbiosis, and potential interventions to restore a healthy female genital tract.

Advances in Research on the Relationship between Vaginal Microbiota and Adverse Pregnancy Outcomes and Gynecological Diseases

The human microbiota inhabiting different parts of the body has been shown to have a significant impact on human health, with the gut microbiota being the most extensively studied in relation to disease. However, the vaginal microbiota is also an essential commensal microbiota in the female body that plays a crucial role in female health. Despite receiving less attention than gut microbiota, its importance in regulating reproductive immunity and its complex dynamic properties have been increasingly recognized in recent years. Advances in research on the relationship between vaginal microbiota and pregnancy outcomes & gynecological diseases in women have shed light on the importance of maintaining a healthy vaginal microbiota. In this review, we aim to compile recent developments in the study of the vaginal microbial ecosystem and its role in female health and reproductive outcomes. We provide a comprehensive account of the normal vaginal microbiota, the association between the vaginal microbiota and pregnancy outcomes, and the impact of the vaginal microbiota on gynecological diseases in women. By reviewing recent research, we hope to contribute to the advancement of academic medicine's understanding of the vaginal microbiota's importance in female health. We also aim to raise awareness among healthcare professionals and the general public of the significance of maintaining a healthy vaginal microbiota for better reproductive health and the prevention of gynecological diseases.

The role of the genital microbiota in the acquisition and pathogenesis of sexually transmitted infections

PURPOSE OF REVIEW

There are an estimated 374 million new sexually transmitted infections (STIs) worldwide every year. Our review article examines the current evidence of how STI acquisition, transmission, and pathogenesis is impacted upon by the genital microbiota, with a focus on epidemiological, biochemical, and immunological features.

RECENT FINDINGS

At least in women, a genital microbiota dominated by lactobacilli has long been considered optimal for reproductive health, while depletion of lactobacilli may lead to a genital microenvironment dominated by anaerobic pathogens, which can manifest clinically as bacterial vaginosis. Recent research efforts have characterized genital microbiota composition in greater resolution, sometimes at species-level, using proteomics, metabolomics, and deep sequencing. This has enhanced our understanding of how specific microbiota members influence acquisition or clinical manifestation of STI pathogen infection. Other advances include a steady, though still slow, increase in the number of studies that sought to determine the genital (penile or urethral) microbiota of males and how it may impact that of their female partners' genital microbiota and risk of STI acquisition. Altogether, these data enabled us to explore the concept that genital microbiota may be sexually transmitted and influence pathogenesis and clinical presentation of other STI.

SUMMARY

With STI infection rates increasing worldwide, it is important now more than ever to find novel STI prevention strategies. Understanding if and how the genital microbiota is a modifiable risk factor for STI transmission, acquisition, and clinical manifestation may prove to be an important strategy in our efforts to curb morbidity in at risk populations.

The vaginal microbiome: A complex milieu affecting risk of human papillomavirus persistence and cervical cancer

The purpose of this review is to describe the existing literature regarding the relationship between the vaginal microbiome, human papillomavirus persistence, and cervical cancer risk, as well as to discuss factors that mediate these relationships. Data suggest that alterations in the vaginal microbiome affect the risk of human papillomavirus infection and persistence, which has downstream effects on cervical dysplasia and cancer risk. The homeostatic Lactobillus species L. crispatus, L. gasseri, L. jensenii act to promote a healthy vaginal environment, while L. iners and pathogens causing bacterial vaginosis are associated with increased inflammation, human papillomavirus infection, cervical dysplasia, and potentially cancer. There are, however, still several large gaps in the literature, particularly related to the modifiable and non-modifiable factors that affect the vaginal microbiome and ensuing risk of pre-cancerous and cancerous lesions. Evidence currently suggests that endogenous and exogenous hormones, tobacco products, and sexual practices influence vaginal microbiome composition, but the nuances of these relationships and how changes in these factors affect dysplasia risk are yet to be delineated. Other studies examining how diet, exercise, race, socioeconomic status, and genetic factors influence the vaginal microbiome are difficult to interpret in the setting of multiple confounders. Future studies should focus on how changes in these modulatory factors might promote a healthy vaginal microbiome to prevent or treat dysplasia in the lower female genital tract.

Cysteine dependence of Lactobacillus iners is a potential therapeutic target for vaginal microbiota modulation

Vaginal microbiota composition affects many facets of reproductive health. Lactobacillus iners-dominated microbial communities are associated with poorer outcomes, including higher risk of bacterial vaginosis (BV), compared with vaginal microbiota rich in L. crispatus. Unfortunately, standard-of-care metronidazole therapy for BV typically results in dominance of L. iners, probably contributing to post-treatment relapse. Here we generate an L. iners isolate collection comprising 34 previously unreported isolates from 14 South African women with and without BV and 4 previously unreported isolates from 3 US women. We also report an associated genome catalogue comprising 1,218 vaginal Lactobacillus isolate genomes and metagenome-assembled genomes from >300 women across 4 continents. We show that, unlike L. crispatus, L. iners growth is dependent on L-cysteine in vitro and we trace this phenotype to the absence of canonical cysteine biosynthesis pathways and a restricted repertoire of cysteine-related transport mechanisms. We further show that cysteine concentrations in cervicovaginal lavage samples correlate with Lactobacillus abundance in vivo and that cystine uptake inhibitors selectively inhibit L. iners growth in vitro. Combining an inhibitor with metronidazole promotes L. crispatus dominance of defined BV-like communities in vitro by suppressing L. iners growth. Our findings enable a better understanding of L. iners biology and suggest candidate treatments to modulate the vaginal microbiota to improve reproductive health for women globally.

Unique roles of vaginal Megasphaera phylotypes in reproductive health

The composition of the human vaginal microbiome has been extensively studied and is known to influence reproductive health. However, the functional roles of individual taxa and their contributions to negative health outcomes have yet to be well characterized. Here, we examine two vaginal bacterial taxa grouped within the genus Megasphaera that have been previously associated with bacterial vaginosis (BV) and pregnancy complications. Phylogenetic analyses support the classification of these taxa as two distinct species. These two phylotypes, Megasphaera phylotype 1 (MP1) and Megasphaera phylotype 2 (MP2), differ in genomic structure and metabolic potential, suggestive of differential roles within the vaginal environment. Further, these vaginal taxa show evidence of genome reduction and changes in DNA base composition, which may be common features of host dependence and/or adaptation to the vaginal environment. In a cohort of 3870 women, we observed that MP1 has a stronger positive association with bacterial vaginosis whereas MP2 was positively associated with trichomoniasis. MP1, in contrast to MP2 and other common BV-associated organisms, was not significantly excluded in pregnancy. In a cohort of 52 pregnant women, MP1 was both present and transcriptionally active in 75.4 % of vaginal samples. Conversely, MP2 was largely absent in the pregnant cohort. This study provides insight into the evolutionary history, genomic potential and predicted functional role of two clinically relevant vaginal microbial taxa.

Vaginal microbiota of American Indian women and associations with measures of psychosocial stress

Molecular-bacterial vaginosis (BV) is characterized by low levels of vaginal Lactobacillus species and is associated with higher risk of sexually transmitted infections (STI). Perceived psychosocial stress is associated with increased severity and persistence of infections, including STIs. American Indians have the highest rates of stress and high rates of STIs. The prevalence of molecular-BV among American Indian women is unknown. We sought to evaluate measures of psychosocial stress, such as historic loss (a multigenerational factor involving slavery, forced removal from one's land, legally ratified race-based segregation, and contemporary discrimination) and their association with the vaginal microbiota and specific metabolites associated with BV, in 70 Northwestern Plains American Indian women. Demographics, perceived psychosocial stressors, sexual practices, and known BV risk factors were assessed using a modified version of the American Indian Service Utilization, Psychiatric Epidemiology, Risk and Protective Factors Project survey. Self-collected mid-vaginal swabs were profiled for bacterial composition by 16S rRNA gene amplicon sequencing and metabolites quantified by targeted liquid-chromatography mass spectrometry. Sixty-six percent of the participants were classified as having molecular-BV, with the rest being either dominated by L. crispatus (10%) or L. iners (24%). High levels of lifetime trauma were associated with higher odds of having molecular-BV (adjusted Odds Ratio (aOR): 2.5, 95% Credible Interval (CrI): 1.1-5.3). Measures of psychosocial stress, including historic loss and historic loss associated symptoms, were significantly associated with lifestyle and behavioral practices. Higher scores of lifetime trauma were associated with increased concentrations of spermine (aFC: 3.3, 95% CrI: 1.2-9.2). Historic loss associated symptoms and biogenic amines were the major correlates of molecular-BV. Historical loss associated symptoms and lifetime trauma are potentially important underlying factors associated with BV.

Insights into the role of vaginal microbiome in women's health

The vaginal microbiome is a complex and dynamic microecosystem that fluctuates continually throughout a woman's life. Lactobacillus, a bacterium that possesses antibacterial properties dominates a healthy vaginal microbiome. Bacterial vaginosis is the most common vaginal disorder that has been linked with the dysbiosis of normal vaginal microbiota. Despite the importance of vaginal microbiome, little is known about functions it performs especially, how it helps in protecting the female reproductive tract. This knowledge gap is a significant impediment to the development of effective and feasible clinical treatments that might be required to improve women's health. Thus, a deeper understanding of the functional aspects and not just the composition of vaginal microbiome may aid in improving the diagnostics and treatment strategies. Recent advancement in molecular methods and computational biology have allowed researchers to acquire more knowledge about the vaginal microbiome. The use of metagenomics (culture-independent high-throughput technology) and bioinformatics tools have improved our understanding of the vaginal microbiome. In this review, we have attempted to explore the factors that may alter normal vaginal microbiota homeostasis such as age, sexual behavior, ethnicity, and hygiene, and so forth. We also discuss the role of probiotics in restoring healthy vaginal microbiome.

A Prospective, Open-Label Pilot Study of Concurrent Male Partner Treatment for Bacterial Vaginosis

Up to 50% of women receiving first-line antibiotics for bacterial vaginosis (BV) experience recurrence within 12 weeks. Evidence suggests that reinfection from an untreated regular sexual partner contributes to recurrence. We conducted a pilot study of 34 heterosexual couples to describe the impact of concurrent partner treatment on the composition of the genital microbiota over a 12-week period. We also determined the acceptability and tolerability of concurrent partner treatment and obtained preliminary estimates of the efficacy of the intervention to inform a randomized controlled trial (RCT). Women received first-line antibiotic treatment for BV (i.e., oral metronidazole or intravaginal clindamycin), and their male partner received oral metronidazole, 400 mg, and 2% clindamycin cream applied topically to penile skin, both twice daily for 7 days. The genital microbiota was characterized at three anatomical sites (women, vaginal; men, cutaneous penile and first-pass urine [representing the urethra]) using 16S rRNA gene sequencing. Immediately posttreatment, concurrent partner treatment significantly reduced the abundance of BV-associated bacteria (false-discovery rate [FDR] corrected P value < 0.05) and altered the overall microbiota composition of all three anatomical sites (P = 0.001). Suppression of BV-associated bacteria was sustained in the majority (81%) of women over the 12-week period (FDR P value < 0.05), despite BV-associated bacteria reemerging at both genital sites in men. In this cohort of women at high risk for recurrence, five recurred within 12 weeks of treatment (17%; 95% confidence interval [CI], 6 to 34%). Importantly, men tolerated and adhered to combination therapy. Our findings provide support for an RCT of combined oral and topical male partner treatment for BV. IMPORTANCE Recurrence of BV following standard treatment is unacceptably high. Posttreatment recurrence is distressing for women, and it imposes a considerable burden on the health care system. Recurrences result in multiple presentations to clinical services and repeated antibiotic use, and the associated obstetric and gynecological sequelae are significant. New treatments to improve long-term BV cure are urgently needed. Here, we used 16S rRNA gene sequencing to investigate changes in the microbiota composition at three genital sites (vagina, penile skin, and male urethra) of heterosexual couples undergoing concurrent partner treatment for bacterial vaginosis (BV). We found that concurrent partner treatment immediately and significantly altered the composition of the genital microbiota of both partners, with a reduction in BV-associated bacteria seen at all three sites. BV cure at 12 weeks posttreatment was higher than expected. These microbiological data provide evidence for continued investigation of partner treatment as a strategy to improve BV cure.

Bacterial vaginosis: drivers of recurrence and challenges and opportunities in partner treatment

Bacterial vaginosis (BV) is the most common vaginal dysbiosis to affect women globally, yet an unacceptably high proportion of women experience BV recurrence within 6 months of recommended antibiotic therapy. The low rate of sustained cure highlights our limited understanding of the pathogenesis of BV recurrence, which has been attributed to possible persistence and re-emergence of BV-associated bacteria (BVAB) or a BV-associated biofilm following antimicrobials and/or reinfection occurring from sexual partners.There is a robust body of evidence to support the exchange of bacteria between partners during sexual activity, and while the hypothesis that women treated for BV are subsequently reinfected with BVAB following sex with an untreated sexual partner is not new, failure of past partner treatment trials has eroded confidence in this concept. If reinfection is a key driver of recurrence, current antimicrobial regimens directed to women alone are unlikely to achieve a high level of sustained cure, and the approach of partner treatment to reduce reinfection is justified. In this manuscript, we present the molecular and epidemiological evidence that underlies the hypothesis that BV is sexually transmitted, and summarise why research that continues to consider sexual partnerships is necessary. We also outline the significant barriers and challenges that we have identified while undertaking partner treatment studies, and we discuss the factors that impact on our ability to determine their effectiveness.Ultimately, the pathogenesis of BV recurrence is likely to be multifaceted and not attributable to a single mechanism in all women. If we are to achieve sustained cure for women, it is likely that combined and individualised approaches to eradicate BVAB, support an optimal vaginal microbiome, and prevent reinfection from partners will be required.

Cytokine profiles and Lactobacillus species presence in pre-menopausal subjects with genital Mycoplasma genitalium or Ureaplasma urealyticum colonization

Background and Purpose:

Lactobacilli play a vital role in protecting the vagina against pathogens. Cytokines are vital components of defense against infections in women. The genital mycoplasmas, Mycoplasma genitalium and Ureaplasma urealyticum, are associated with various infectious diseases in adults and infants. The objective of our study is to identify differences in cytokine profile and Lactobacillus species dominance between a study group of non-pregnant pre-menopausal women with genital M. genitalium or U. urealyticum colonization and a control group of non-pregnant pre-menopausal women without genital M. genitalium or U. urealyticum colonization.

Methods:

A real-time polymerase chain reaction was performed to measure Lactobacillus species in vaginal swab samples. Cytokine analysis was performed using multiplex immunoassay techniques. Analysis of variance confirmed a significant difference in cytokine profiles between patient groups, with t-tests identifying the most significantly different cytokines. Categorical data analysis identified significant patterns of relative Lactobacillus species dominance in the study group.

Results:

Lactobacillus iners was the predominant Lactobacillus species in the control group (p = 0.005). There were no dominant Lactobacillus species observed in the study group. Vascular endothelial growth factor A (p = 0.002), interleukin-8 (p = 0.001), and interleukin-1β (p = 0.049) were expressed significantly higher in the study group, whereas interleukin-1 receptor antagonist (p < 0.001), interleukin-10 (p = 0.001), interleukin-12 (p = 0.002), and interferon-γ (p = 0.022) were expressed higher in the control group. Association matrices for cytokines were significantly different between two groups (p < 0.001), with mostly negative associations in the control group and mostly positive associations in the study group.

Conclusion:

Cytokine levels, their associations, and the patterns of Lactobacillus species dominance are observed to significantly diverge on the basis of M. genitalium and U. urealyticum colonization among non-pregnant pre-menopausal women.

The Complex Link between the Female Genital Microbiota, Genital Infections, and Inflammation

The female genital tract microbiota is part of a complex ecosystem influenced by several physiological, genetic, and behavioral factors. It is uniquely linked to a woman's mucosal immunity and plays a critical role in the regulation of genital inflammation. A vaginal microbiota characterized by a high abundance of lactobacilli and low overall bacterial diversity is associated with lower inflammation. On the other hand, a more diverse microbiota is linked to high mucosal inflammation levels, a compromised genital epithelial barrier, and an increased risk of sexually transmitted infections and other conditions. Several bacterial taxa such as Gardnerella spp., Prevotella spp., Sneathia spp., and Atopobium spp. are well known to have adverse effects; however, the definitive cause of this microbial dysbiosis is yet to be fully elucidated. The aim of this review is to discuss the multiple ways in which the microbiota influences the overall genital inflammatory milieu and to explore the causes and consequences of this inflammatory response. While there is abundant evidence linking a diverse genital microbiota to elevated inflammation, understanding the risk factors and mechanisms through which it affects genital health is essential. A robust appreciation of these factors is important for identifying effective prevention and treatment strategies.

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

BACKGROUND

Vaginal lubricants are commonly used during gynecological examinations, during sexual activities, or to alleviate vaginal dryness. Many lubricants contain potentially bacteriostatic or bactericidal agents (parabens, chlorhexidine gluconate, nonoxynol-9). Our objective was to evaluate the impact of lubricants that vary in formulation on the growth and viability of vaginal Lactobacillus species and vaginal epithelial cell (VEC) colonization in an in vitro model.

METHODS

Growth curve, disk diffusion, and minimal inhibitory assays were used to determine the impact of lubricants or excipients on the growth of Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus jensenii, and Lactobacillus iners. L. crispatus strain was used in VEC colonization assays. Statistical differences were determined by analysis of variance.

RESULTS

Lubricants containing chlorhexidine gluconate or nonoxynol-9 (N-9; Conceptrol, K-Y Jelly, and Surgilube) significantly inhibited Lactobacillus species growth (P < 0.05). In contrast, other clinical lubricants (E-Z Lubricating Jelly, McKesson Lubricating) and personal lubricants (Astroglide Liquid, Good Clean Love Almost Naked, K-Y Warming Jelly) did not exhibit this effect. Chlorhexidine gluconate had a detrimental effect on Lactobacillus growth and exhibited stronger antimicrobial activity compared with methylparaben and propylparaben (P < 0.0001). There were lubricants that did not induce cytotoxicity in VEC (Good Clean Love Almost Naked, E-Z Lubricating Jelly, McKesson Lubricating Jelly), but these products did substantially decrease the attachment of L. crispatus to VEC, particularly when VEC were preexposed to lubricants before inoculation with bacteria (P < 0.0001).

CONCLUSIONS

This in vitro model indicates that select vaginal lubricants, particularly those with chlorhexidine gluconate, have potentially adverse effects on women's health by reducing growth and recolonization of vaginal Lactobacillus species.

Controversies in the prevention of spontaneous preterm birth in asymptomatic women: an evidence summary and expert opinion

Preterm birth prevention is multifaceted and produces many nuanced questions. This review addresses six important clinical questions about preterm birth prevention as voted for by members of the UK Preterm Clinical Network. The questions cover the following areas: preterm birth prevention in 'low-risk' populations; screening for asymptomatic genital tract infection in women at high risk of preterm birth; cervical length screening with cerclage or vaginal pessary in situ; cervical shortening whilst using progesterone; use of vaginal progesterone in combination with cervical cerclage; and optimal advice about intercourse for women at high risk of preterm birth.

Vaginal microbiota and the potential of Lactobacillus derivatives in maintaining vaginal health

Human vagina is colonised by a diverse array of microorganisms that make up the normal microbiota and mycobiota. Lactobacillus is the most frequently isolated microorganism from the healthy human vagina, this includes Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii. These vaginal lactobacilli have been touted to prevent invasion of pathogens by keeping their population in check. However, the disruption of vaginal ecosystem contributes to the overgrowth of pathogens which causes complicated vaginal infections such as bacterial vaginosis (BV), sexually transmitted infections (STIs), and vulvovaginal candidiasis (VVC). Predisposing factors such as menses, pregnancy, sexual practice, uncontrolled usage of antibiotics, and vaginal douching can alter the microbial community. Therefore, the composition of vaginal microbiota serves an important role in determining vagina health. Owing to their Generally Recognised as Safe (GRAS) status, lactobacilli have been widely utilised as one of the alternatives besides conventional antimicrobial treatment against vaginal pathogens for the prevention of chronic vaginitis and the restoration of vaginal ecosystem. In addition, the effectiveness of Lactobacillus as prophylaxis has also been well-founded in long-term administration. This review aimed to highlight the beneficial effects of lactobacilli derivatives (i.e. surface-active molecules) with anti-biofilm, antioxidant, pathogen-inhibition, and immunomodulation activities in developing remedies for vaginal infections. We also discuss the current challenges in the implementation of the use of lactobacilli derivatives in promotion of human health. In the current review, we intend to provide insights for the development of lactobacilli derivatives as a complementary or alternative medicine to conventional probiotic therapy in vaginal health.

Gardnerella vaginalis Clade Distribution Is Associated With Behavioral Practices and Nugent Score in Women Who Have Sex With Women

BACKGROUND

Gardnerella vaginalis is detected in women with and without bacterial vaginosis (BV). Identification of 4 G. vaginalis clades raised the possibility that pathogenic and commensal clades exist. We investigated the association of behavioral practices and Nugent Score with G. vaginalis clade distribution in women who have sex with women (WSW).

METHODS

Longitudinal self-collected vaginal specimens were analyzed using established G. vaginalis species-specific and clade-typing polymerase chain reaction assays. Logistic regression assessed factors associated with detection of G. vaginalis clades, and multinomial regression assessed factors associated with number of clades.

RESULTS

Clades 1, 2, and 3 and multiclade communities (<2 clades) were associated with Nugent-BV. Clade 1 (odds ratio [OR], 3.36; 95% confidence interval [CI], 1.65-6.84) and multiclade communities (relative risk ratio [RRR], 9.51; 95% CI, 4.36-20.73) were also associated with Lactobacillus-deficient vaginal microbiota. Clade 4 was neither associated with Nugent-BV nor Lactobacillus-deficient microbiota (OR, 1.49; 95% CI, 0.67-3.33). Specific clades were associated with differing behavioral practices. Clade 1 was associated with increasing number of recent sexual partners and smoking, whereas clade 2 was associated with penile-vaginal sex and sharing of sex toys with female partners.

CONCLUSIONS

Our results suggest that G. vaginalis clades have varying levels of pathogenicity in WSW, with acquisition occurring through sexual activity. These findings suggest that partner treatment may be an appropriate strategy to improve BV cure.

Sex is associated with the persistence of non-optimal vaginal microbiota following treatment for bacterial vaginosis: a prospective cohort study

OBJECTIVE

Determine the associations between factors and sexual practices and the composition of the vaginal microbiome (VM) of women treated for bacterial vaginosis (BV).

DESIGN

Prospective cohort study.

SETTING

The Melbourne Sexual Health Centre, Melbourne, Australia.

POPULATION

Seventy-five reproductive-age women diagnosed with clinical BV, treated with first-line antibiotics and followed for up to 6 months.

METHODS

Women self-collected vaginal swabs and completed questionnaires at enrolment, the day following antibiotics and monthly for up to 6months until BV recurrence or no BV recurrence (n = 430 specimens). Bacterial composition was determined using 16S rRNA gene amplicon sequencing. The effects of ongoing factors on VM composition (utilising 291 monthly specimens) were assessed using generalised estimating equations population-averaged models, which accounted for repeated measures within individuals.

MAIN OUTCOME MEASURES

The relative abundance of vaginal bacterial taxa.

RESULTS

Women who reported ongoing sex with a regular sexual partner (RSP) had a VM comprised of increased relative abundance of non-optimal BV-associated bacteria (Adjusted co-efficient [Adjusted co-eff] = 11.91, 95% CI 3.39to20.43, P = 0.006) and a decreased relative abundance of optimal, Lactobacillus species (Adjusted co-eff = -12.76, 95% CI -23.03 to -2.49, P = 0.015). A history of BV was also associated with a decreased relative abundance of Lactobacillus spp. (Adjusted co-eff = -12.35, 95% CI -22.68, P = 0.019). The relative abundance of Gardnerella, Atopobium and Sneathia spp. increased following sex with an RSP.

CONCLUSIONS

Sex with an untreated RSP after BV treatment was associated with a VM comprised of non-optimal BV-associated bacteria. BV treatment approaches may need to include partner treatment if they are to achieve a sustained optimal VM associated with improved health outcomes.

TWEETABLE ABSTRACT

Sex drives a return to a 'non-optimal' vaginal microbiota after antibiotics for bacterial vaginosis.