Bacterial Vaginosis: Current Diagnostic Avenues and Future Opportunities

In vivo assessment of the effect of gel containing lactic acid and glycogen on vaginal microbiota and pH of asymptomatic women of reproductive age

Background Vaginal dysbiosis is considered a risk factor for the development of gynecological and obstetric complications. This study aimed to evaluate the effects of vaginal gel containing lactic acid on vaginal pH, microbiota composition, and Candida species in asymptomatic women of reproductive age.

METHODS

55 menstruating women, with no gynecological complaints, participated in the study, using a gel containing lactic acid twice a week, for 8 weeks. Assessments were conducted before and after the intervention, including measurements of vaginal pH, Nugent score, vaginal microbiota characteristics (alpha diversity index and Community State Types [CSTs] classification), and identification of Candida species.

RESULTS

At baseline, 36.4% of women exhibited CST type IV vaginal microbiota, followed by CST type III (30.9%), with vaginal pH values ranging from 4 to 5. After the intervention, there was a significant reduction in vaginal pH (p = 0.0057) and Nugent scores (p = 0.0047). Furthermore, a statistically significant decline was observed in the prevalence of unfavorable taxonomic groups, including Prevotella amnii and Bacterial Vaginosis Associated Bacterium 1, while vaginal lactobacilli remained unaffected. Despite these positive changes, the intervention did not result in a statistically significant alteration in microbial diversity or CST composition (p = 0.12). The gel was well-tolerated, with a low incidence of mild adverse effects reported.

CONCLUSIONS

The lactic acid-containing gel demonstrated a significant reduction in vaginal pH and Nugent scores in asymptomatic women, indicating possible improvement in vaginal health, that needs to be confirmed in a placebo-controlled study. Although the intervention did not influence microbial diversity and the type of vaginal microbiota at the end of the study, it was able to reduce the prevalence of some taxonomic groups after intervention with the vaginal gel.

Cranberry Oil: A Potent Natural Intimate Care Ingredient Displaying Antioxidant and Anti-Inflammatory Effects and Promoting Beneficial Vaginal Lactobacillus

Cranberry oil is known for nutritional benefits, and this work is aimed at studying its soothing properties and potential as an intimate care ingredient. The antioxidant, anti-inflammatory, and anti-irritation properties of cranberry oil were evaluated on epithelial cells and tissues, including the vaginal epithelium. The impact of the oil on vaginal microbiota was assessed in vitro. Cranberry oil reduced oxidative stress in keratinocytes (ROS -43%) and lowered inflammation by lessening the release of cytokines IL-8 (-33%) and TNF-α (-32%). Irritation induced by sodium dodecyl sulfate (SDS) in skin explants was lowered by 24%. Cranberry oil and fruit extract acted synergistically on inflammation, decreasing TNF-α release by 75% (vs. -34% and -16%, respectively). Cranberry oil reduced inflammation on EpiVaginal™ tissue, decreasing IL-6 by 36%. The minimum inhibitory concentration (MIC) of cranberry oil on the pathogenic vaginal microorganisms C. albicans and G. vaginalis was 0.5% and 0.1%, respectively. The oil promoted the growth of commensal L. jensenii (×79 at 0.1%) and favored a high proportion of lactic acid bacteria when co-cultured with C. albicans. Cranberry oil has antioxidant, anti-inflammatory, and soothing properties on skin. Anti-inflammatory activity was confirmed on vaginal epithelium, and initial in vitro evidence indicates that the oil can balance vaginal flora to prevent dysbiosis.

Best among the key molecular diagnostic markers of bacterial vaginosis

To assess bacterial vaginosis (BV)-related primary molecular diagnostic markers of Lactobacillus crispatus, Gardnerella vaginalis, Fannyhessea vaginae, bacterial vaginosis-associated bacteria 2 (BVAB-2), Megasphaera-1 and Megasphaera-2 and to discover molecular diagnostic indicators of BV with the most economic value for the efficient diagnosis of BV.All vaginal secretion specimens, including 122 BV-positive cases and 130 BV-negative controls were collected. First, quantitative polymerase chain reaction (PCR) was used to determine the levels of above the six bacteria. Then, the detection rates, sensitivity, specificity, diagnostic threshold, and receiver operating characteristic (ROC) curve were compared. Megasphaera-1 and Megasphaera-2 were detected in the BV-positive group, with a low detection rate of 35.25% and 19.67% respectively. The sensitivity and specificity of the above four bacteria were 95.90%/72.31%, 82.79%/92.48%, 72.13%/95.38%, and 56.56%/94.62% respectively, using the cut-off value for the diagnosis of BV. When combinations of L. crispatus with G. vaginalis, F. vaginae, and BVAB-2 were performed respectively, their sensitivity and specificity were 99.29%/97.79%, 98.86%/98.72%, and 98.22%/98.51% in sequence.It is difficult to diagnose BV using only one species, however, combinations of L. crispatus with G. vaginalis or F. vaginae showed a better diagnostic effect, particularly with the combination of L. crispatus and G. vaginalis.

Cervicovaginal microbiome and natural history of Chlamydia trachomatis in adolescents and young women

This study investigated the cervicovaginal microbiome's (CVM's) impact on Chlamydia trachomatis (CT) infection among Black and Hispanic adolescent and young adult women. A total of 187 women with incident CT were matched to 373 controls, and the CVM was characterized before, during, and after CT infection. The findings highlight that a specific subtype of bacterial vaginosis (BV), identified from 16S rRNA gene reads using the molBV algorithm and community state type (CST) clustering, is a significant risk factor for CT acquisition. A microbial risk score (MRS) further identified a network of bacterial genera associated with increased CT risk. Post treatment, the CVM associated with CT acquisition re-emerged in a different subset of cases leading to reinfection. Additionally, the analysis showed a connection between post-treatment CVM and the development of pelvic inflammatory disease (PID) and miscarriage, further underscoring the CVM's contributing role to incident CT natural history and highlighting its consideration as a therapeutic target.

Quantitative profiling of the vaginal microbiota improves resolution of the microbiota-immune axis

BACKGROUND

The composition of the vaginal microbiota is closely linked to adverse sexual and reproductive health outcomes, due in part to effects on genital immunology. Compositional approaches such as metagenomic sequencing provide a snapshot of all bacteria in a sample and have become the standard for characterizing the vaginal microbiota, but only provide microbial relative abundances. We hypothesized that the addition of absolute abundance data would provide a more complete picture of host-microbe interactions in the female genital tract.

RESULTS

We analyzed cervicovaginal secretions from 196 female sex workers in Kenya and found that bacterial load was elevated among women with diverse, bacterial vaginosis (BV)-type microbiota and lower among women with Lactobacillus predominance. Bacterial load was also positively associated with proinflammatory cytokines, such as IL-1α, and negatively associated with chemokines, such as IP-10. The associations between bacterial load and immune factors differed across bacterial community states, but L. crispatus predominance was the only microbial community where higher bacterial load was not associated with higher proinflammatory cytokines. Total vaginal bacterial load was also a stronger predictor of the genital immune environment than BV by Nugent score, the current clinical standard, in the Kenya-based cohort and in a Uganda-based confirmatory cohort.

CONCLUSIONS

Our results suggest that total vaginal bacterial load is at least as strong a predictor of the genital immune milieu as current BV clinical diagnostic tools, supporting exploration of the vaginal bacterial load as a predictor of adverse reproductive and sexual health outcomes. Video Abstract.

Relationship between dietary inflammatory index, plant-based dietary index, and bacterial vaginosis: A case-control study

OBJECTIVE

Bacterial vaginosis (BV) is a common inflammatory condition affecting the vaginal microbiome. In the present study we aimed to explore the relationship between dietary inflammatory index, plant-based dietary index, and BV.

METHODS

In this case-control study, 143 individuals with BV and 151 healthy participants aged 15-45 years were included. Bacterial vaginosis diagnosis was based on the Amsel criteria by a gynecologist. Participants' dietary intakes over the past year were assessed using a 168-item food frequency questionnaire. Logistic regression models were employed to analyze the association between dietary inflammatory index, plant-based dietary index, and BV odds.

RESULTS

Our study revealed that elevated dietary inflammatory index scores were strongly associated with higher BV odds in the crude model (odds ratio [OR]: 2.88, 95% confidence interval [CI]: 1.57-5.30, P value <0.001), and even after accounting for potential confounding factors (adjusted OR: 3.52, 95% CI: 1.66-7.46, P value = 0.001). While no significant relationship was observed between total plant-based dietary index and healthy plant-based dietary index scores with BV odds, a clear positive association existed between unhealthy plant-based dietary index and the odds of BV (aOR: 2.13, 95% CI: 1.09-4.15, P value = 0.018).

CONCLUSION

A positive correlation may exist between unhealthy plant-based dietary index and the likelihood of BV. Furthermore, the dietary inflammatory index may remain linked to increased BV odds.

Feasibility, safety and tolerability of estrogen and/or probiotics for improving vaginal health in Canadian African, Caribbean, and Black women: A pilot phase 1 clinical trial

BACKGROUND

A dysbiotic vaginal microbiome (VMB) is associated with clinical conditions such as bacterial vaginosis (BV) and an increased risk of human immunodeficiency virus (HIV-1) infection. Considering the high prevalence of BV among African, Caribbean and Black (ACB) women, we conducted a prospective, randomized, open-label phase 1 clinical trial to determine the feasibility, safety and tolerability of administering low-dose estrogen, probiotics or both in combination to improve vaginal health and decrease HIV-1 susceptibility.

METHODS

ACB women aged 18-49 from the Greater Toronto Area (GTA) were randomized to one of four study arms: intravaginal estradiol (Estring©; 7.5mg/day); a vaginal probiotic (RepHresh™ Pro-B™) administered twice daily; a combination of Estring© and vaginal RepHresh™ Pro-B™ (twice daily); or the Estring© and oral RepHresh™ Pro-B™ (twice daily), for a duration of 30 days. Feasibility was evaluated through enrolment, retention, and adherence rates, while safety and tolerability were determined by a pre- and post-treatment blood panel and reported adverse events (AEs).

RESULTS

Overall, 63 ACB women were screened, 50 were enrolled and received the intervention while 41 completed the study, resulting in 80% enrollment and 82% retention rates. Overall adherence to the study protocol was high at 93%, with an adherence of 92% for RepHresh™ Pro-B™ and 97% for Estring©. A total of 88 AEs were reported by 29 participants which were mild (66/88; 75%) and largely resolved (82/88;93%) by the end of the study, with no serious AEs (SAEs) noted. In addition, a panel of safety blood markers measured pre- and post-intervention confirmed no clinically significant changes in blood chemistry or blood cell count.

CONCLUSION

Overall, the administration of intravaginal estrogen and/or probiotics in pre-menopausal ACB women is feasible, safe, and well tolerated.

TRIAL REGISTRATION

The trial was registered with Clinicaltrials.gov (NCT03837015) and CIHR HIV Clinical Trials (CTN308).

Exploring the Potential Use of Probiotics, Prebiotics, Synbiotics, and Postbiotics as Adjuvants for Modulating the Vaginal Microbiome: a Bibliometric Review

Women's health is related to several factors that include physical, mental, and reproductive health. Additionally, the vaginal microbiota modulation performs a fundamental role in the regulation of physiological homeostasis and dysbiosis, which provides us a potential overview of the use of different biotic agents and their implications for female health. The objective of this work was propitiated insights and conception about the influence of probiotics, prebiotics, synbiotics, and postbiotics as adjuvants for prevention/treatment on the main infections that can affect women's health. Therefore, seventy-one studies published in the Web of Science Core Collection database from 1999 to 2024 were evaluated and performed to a bibliometric analysis employing the VOSviewer software for scientific mapping and network analysis. Our results suggest that administration of biotic agents as adjuvants are relevant for the prevention and/or treatment of the main diseases that affect female health, since they contribute to a healthy vaginal microbiota through anti-inflammatory and antimicrobial activities. Most clinical studies have demonstrated the effectiveness of intervention using probiotics to the detriment of other biotic agents in women's health, being bacterial vaginosis, polycystic ovary syndrome, and vulvovaginal candidiasis, the main diseases evaluated. However, preclinical studies have emphasized that the inhibition of pathogens responsible for the process of vaginal dysbiosis may be due to the formation of biofilm and the synthesis of compounds that could prevent the adhesion of these microorganisms. Future perspectives point to the beneficial modulation of the vaginal microbiota by biotic agents as a promising adjuvant approach to improve women's health.

Genetic association between human skin microbiota with vaginitis: a two-sample Mendelian randomization study

The human skin microbiome is closely associated with various diseases. We aimed to find the causal association of the human skin microbiome with vaginitis. A two-way two-sample Mendelian randomization study used summary statistics of the human skin microbiota from the largest genome-wide association study meta-analysis. Pooled statistics for vaginitis disease were obtained from the FinnGen consortium R10 release. Inverse variance weighted, MR-Egger, weighted median, weighted model, MR-PRESSO, and STEIGER methods were used to test for causal associations between different parts of the human skin microbiota and vaginitis disease in either dry or moist environments. IVW estimates suggest that phylococcus hominischaracterizes a protective effect against vaginitis lesions at the Antecubitalfossa wet site. Staphylococcus in the dry state at the Dorsalforearm site also demonstrated a protective effect against vaginitis lesions. Micrococcus showed a trend of up-regulation of vaginitis risk under IVW method estimation. In contrast, Anaerococcus and Veillonella were associated with a low risk of vaginitis as estimated by the IVW method: ASV061 and ASV065. In the Class, IVW estimation showed that Bacilli at Antecubitalfossa site had an increased risk effect on vaginitis in the moist skin condition. Similarly in Genus, Staphylococcus at Antecubitalfossa sites had an increased risk effect against vaginitis in the moist skin condition. Based on the results of the inverse MR analysis, no significant causal effect of vaginitis on the human skin microbiota was found. This two-sample bidirectional Mendelian randomization study found a causal relationship between seven human skin microbiota and vaginitis, further enriching our understanding of the value of skin flora in reproductive diseases such as vaginitis.

VIBES: A consensus subtyping of the vaginal microbiota reveals novel classification criteria

This study aimed to develop a robust classification scheme for stratifying patients based on vaginal microbiome. By employing consensus clustering analysis, we identified four distinct clusters using a cohort that includes individuals diagnosed with Bacterial Vaginosis (BV) as well as control participants, each characterized by unique patterns of microbiome species abundances. Notably, the consistent distribution of these clusters was observed across multiple external cohorts, such as SRA022855, SRA051298, PRJNA208535, PRJNA797778, and PRJNA302078 obtained from public repositories, demonstrating the generalizability of our findings. We further trained an elastic net model to predict these clusters, and its performance was evaluated in various external cohorts. Moreover, we developed VIBES, a user-friendly R package that encapsulates the model for convenient implementation and enables easy predictions on new data. Remarkably, we explored the applicability of this new classification scheme in providing valuable insights into disease progression, treatment response, and potential clinical outcomes in BV patients. Specifically, we demonstrated that the combined output of VIBES and VALENCIA scores could effectively predict the response to metronidazole antibiotic treatment in BV patients. Therefore, this study's outcomes contribute to our understanding of BV heterogeneity and lay the groundwork for personalized approaches to BV management and treatment selection.

Sustained dual delivery of metronidazole and viable Lactobacillus crispatus from 3D-printed silicone shells

Bacterial vaginosis (BV) is an imbalance of the vaginal microbiome in which there are limited lactobacilli and an overgrowth of anaerobic and fastidious bacteria such as Gardnerella. The propensity for BV recurrence is high, and therapies involving multiple treatment modalities are emerging to meet this need. However, current treatments requiring frequent therapeutic administration are challenging for patients and impact user compliance. Three-dimensional (3D)-printing offers a novel alternative to customize platforms to facilitate sustained therapeutic delivery to the vaginal tract. This study designed a novel vehicle intended for dual sustained delivery of both antibiotic and probiotic. 3D-printed compartmental scaffolds consisting of an antibiotic-containing silicone shell and a core containing probiotic Lactobacillus were developed with multiple formulations including biomaterials sodium alginate (SA), polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyethylene oxide (PEO), and kappa-carrageenan (KC). The vehicles were loaded with 50 μg of metronidazole/mg polymer and 5 × 107 CFU of L. crispatus/mg scaffold. Metronidazole-containing shells exhibited cumulative drug release of 324.2 ± 31.2 μg/mL after 14 days. Multiple polymeric formulations for the probiotic core demonstrated cumulative L. crispatus recovery of >5 × 107 CFU/mg scaffold during this timeframe. L. crispatus-loaded polymeric formulations exhibited ≥2 log CFU/mL reduction in free Gardnerella in the presence of VK2/E6E7 vaginal epithelial cells. As a first step towards the goal of facilitating patient compliance, this study demonstrates in vitro effect of a novel 3D-printed dual antibiotic and probiotic delivery platform to target BV.

Vaginal Microbiome and the Risk of Preterm Birth in Women Living With HIV: A Scoping Review

There are sparse data on the role of the vaginal microbiome (VMB) in pregnancy among pregnant women living with HIV (PWLWH) and its association with spontaneous preterm birth (sPTB). We conducted a scoping review to assess associations between vaginal microbiota and sPTB among PWLWH. Three studies were included, representing a total of 180 PWLWH out of 652 total pregnancies. All studies used modern DNA sequencing methods (16S rRNA amplification, metagenomics, or metatranscriptomics). PWLWH had higher VMB richness and diversity compared to HIV-uninfected pregnant women and higher sPTB rates in two of three studies. A higher proportion of sPTB among PWLWH was observed in those with Lactobacillus-deficient, anaerobe-dominant vaginal microbiota. In two of three studies, higher concentrations of vaginal inflammation markers were associated with increased VMB richness and diversity. HIV status was independently associated with sPTB. It is unclear if increased vaginal microbial diversity among PWLWH or increased vaginal inflammation contributes more to PTB, but HIV does appear to alter the VMB in pregnant individuals and may also affect PTB rates in microbiome-independent pathways. Given the limited number of studies, heterogeneity in sample size, sample collection methods, and inconsistent results it is difficult to causally link HIV, VMB, inflammatory cytokines, and sPTB.

Polymicrobial consortia in the pathogenesis of biofilm vaginosis visualized by FISH. Historic review outlining the basic principles of the polymicrobial infection theory

The manuscript disputes the exclusive mono-infectious way of thinking, which presumes that for every infection only one pathogen is responsible and sufficient, when infectious vectors, close contact and reduced immunity meet. In situations involving heavily colonized anatomical sites such an approach often ends in insoluble contradictions. Upon critical reflection and evaluation of 20 years research on spatial organization of vaginal microbiota it is apparent, that in some situations, pathogens may act and operate in permanent, structurally organized consortia, whereas its individual components may be innocuous and innocent, failing to express any pathogenic effect. In these cases, consortia are the true pathogens responsible for many infectious conditions, which usually remain unrecognized as long as improperly diagnosed. The structure of such consortia can be unraveled using ribosomal fluorescence in situ hybridization (FISH). FISH methodology, that not only offers an ex vivo opportunity to recognize bacterial species, but provides unique physical insight into their specific role in the pathogenesis of polymicrobial infections. Ribosomal FISH technique applied to both, women with bacterial vaginosis (BV) and their male partners, has added significantly to our understanding of the pathogenesis of this condition and contributed to appreciating the mechanisms of polymicrobial, community-based infection, potentially leading to therapeutic advances.

Synthetic bacterial consortia transplantation attenuates vaginal inflammation and modulates the immune response in a mouse model of Gardnerella vaginalis-induced bacterial vaginosis

This study aimed to evaluate the efficacy of synthetic bacterial consortia transplantation (SBCT) and compare it with VMT (vaginal microbiota transplantation) in a mouse model of Gardnerella vaginalis-induced Bacterial vaginosis (BV). A murine model of G. vaginalis-induced BV was established, and mice were treated with SBCT, VMT, or saline. Histopathological changes, inflammatory cytokine levels, pro-inflammatory biomarker expression, helper T cell transcription factor expression, and vaginal microbiota composition were assessed. SBCT and VMT effectively suppressed G. vaginalis growth, reduced inflammation, and restored vaginal microbiota diversity. Both treatments attenuated epithelial damage, downregulated pro-inflammatory cytokines (IL-1β and IL-8), and upregulated the anti-inflammatory cytokine IL-10. SBCT and VMT also inhibited NF-κB activation, suppressed IL-17 expression, and enhanced Foxp3 expression in vaginal tissues. SBCT is a promising therapeutic approach for treating BV, as it effectively modulates the immune response and restores vaginal microbiota diversity in a mouse model of G. vaginalis-induced BV.

A Controlled, Retrospective, Single-Center Study to Evaluate the Role of a Probiotic Mixture Administered during Pregnancy in Reducing Streptococcus Agalactiae Swab Positivity and the Frequency of Premature Rupture of Amniochorionic Membranes

Intrapartum antibiotic prophylaxis, considered able to prevent streptococcal transmission from mother to newborn and its severe negative consequences, leads to microbiota dysbiosis, described as having a negative impact on well-being in both elements of the dyad. Enterococcus faecium L3 is a probiotic strain capable of exerting strong antagonistic activity against most streptococci, including S. agalactiae, due to the production of bacteriocins (known as enterocins A and B). A proprietary probiotic mixture containing the strain L3 demonstrated, in 2016, a significant reduction in episodes of PROM in pregnant women, with a less-than-expected effect on the vaginal-rectal presence of the pathogen S. agalactiae. With the aim of confirming the role exerted by the probiotic mixture in PROM episodes and to better understand the value of its impact on the clinical detection of S. agalactiae, we have retrospectively analyzed the results obtained in 125 L3-treated (over 12 weeks) women versus 125 untreated controls. Despite some limitations, our analysis has confirmed the role exerted by the probiotic in significantly reducing the following: (1) episodes of PROM, (2) vaginal-rectal positivity for S. agalactiae, and (3) the need to administer intrapartum antibiotics for prophylaxis. It likely also suggests operating using a cultural method very specific to S. agalactiae when testing women who were administered an Enterococcus-based probiotic.

Antibiofilm Agents for the Treatment and Prevention of Bacterial Vaginosis: A Systematic Narrative Review

BACKGROUND

Bacterial vaginosis (BV) is difficult to eradicate due to BV biofilms protecting BV bacteria (Gardnerella, Prevotella, and other genera). With the growing understanding of biofilms, we systematically reviewed the current knowledge on the efficacy of anti-BV biofilm agents.

METHODS

We searched literature in the Scopus, Medline, and Embase databases for empirical studies investigating substances for the treatment of BV biofilms or prevention of their recurrence and their efficacy and/or safety.

RESULTS

Of 201 unique titles, 35 satisfied the inclusion criteria. Most studies (89%) reported on preclinical laboratory research on the efficacy of experimental antibiofilm agents (80%) rather than their safety. Over 50% were published within the past 5 years. Agents were classified into 7 groups: antibiotics, antiseptics, cationic peptides, enzymes, plant extracts, probiotics, and surfactants/surfactant components. Enzymes and probiotics were most commonly investigated. Earlier reports of antibiotics having anti-BV biofilm activity have not been confirmed. Some compounds from other classes demonstrated promising anti-BV biofilm efficacy in early studies.

CONCLUSIONS

Further research is anticipated on successful antibiofilm agents. If confirmed as effective and safe in human clinical trials, they may offer a breakthrough in BV treatment. With rising antibiotic resistance, antibiofilm agents will significantly improve the current standard of care for BV management.

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.

Clinical Applicability of Microbiota Sampling in a Subfertile Population: Urine versus Vagina

The urogenital microbiota is increasingly gaining recognition as a significant contributor to reproductive health. Recent studies suggest that microbiota can serve as predictors for fertility treatment outcomes. Our objective was to investigate the degree of similarity in microbial composition between patient-collected urine and vaginal samples in a subfertile population. We enrolled women of reproductive age (20-44 years) diagnosed with subfertility and requiring in vitro fertilization (IVF) or IVF with intracytoplasmic sperm injection (IVF-ICSI) treatment. They self-collected both mid-stream urine samples and vaginal swabs before commencing the IVF or IVF-ICSI procedure. All samples were analysed using the intergenic spacer profiling (IS-pro) technique, a rapid clinical microbiota analysis tool. The main outcome measures were the degree of similarity of microbial composition between the two different, but simultaneously collected, samples. Our findings revealed a high correlation (R squared of 0.78) in microbiota profiles between paired urine and vaginal samples from individual patients. Nevertheless, the urinary microbiota profiles contained fewer species compared to the vaginal microbiota, resulting in minor but distinguishable differences. Furthermore, different subfertility diagnoses appeared to be associated with differences in microbial profiles. A noteworthy observation was the exclusive presence of Escherichia coli (E. coli) in both samples of women diagnosed with male factor subfertility. In conclusion, since urinary microbiota profiles seem to represent a diluted version of the vaginal microbiota, vaginal microbiome sampling to predict fertility treatment outcome seems preferable. To enhance the success of fertility treatments, further research is needed to gain deeper insights into a putative causal role of microbiota in the mechanisms of subfertility.

Characterization of vaginal Lactobacillus in biologically relevant fluid using surface-enhanced Raman spectroscopy

The native vaginal microbiome plays a crucial role in maintaining vaginal health and disruption can have significant consequences for women during their lifetime. While the composition of the vaginal microbiome is important, current methods for monitoring this community are lacking. Clinically used techniques routinely rely on subjective analysis of vaginal fluid characteristics or time-consuming microorganism culturing. Surface-enhanced Raman spectroscopy (SERS) can aid in filling this gap in timely detection of alterations in the vaginal microbiome as it can discriminate between bacterial species in complex solutions including bacterial mixtures and biofluids. SERS has not previously been applied to study variations in vaginal Lactobacillus, the most common species found in the vaginal microbiome, in complex solutions. Herein, the SERS spectra of Lactobacillus crispatus (L. crispatus) and Lactobacillus iners (L. iners), two of the most common vaginal bacteria, was characterized at physiologically relevant concentrations. Subsequently, the ability of SERS to detect L. crispatus and L. iners in both pure mixtures and when mixed with a synthetic vaginal fluid mimicking solution was determined. In both pure and complex solutions, SERS coupled with partial least squares regression predicted the ratiometric bacterial content with less than 10% error and strong goodness of prediction (Q2 > 0.9). This developed method highlights the applicability of SERS to predict the dominant Lactobacillus in the vaginal micro-environment toward the monitoring of this community.

Computational approach for drug discovery against Gardnerella vaginalis in quest for safer and effective treatments for bacterial vaginosis

Bacterial vaginosis (BV), primarily attributed to Gardnerella vaginalis, poses significant challenges due to antibiotic resistance and suboptimal treatment outcomes. This study presents an integrated approach to identify potential drug targets and screen compounds against this bacterium by leveraging a computational methodology. Subtractive proteomics of the reference strain ASM286196v1/UMB0386 (assembly accession: GCA_002861965.1) facilitated the prioritization of proteins with essential bacterial functions and pathways as potential drug targets. We selected 3-deoxy-7-phosphoheptulonate synthase (aroG gene product; also known as DAHP synthase) for downstream analysis. Molecular docking was employed in PyRx (AutoDock Vina) to predict binding affinities between aroG inhibitors from the ZINC database and 3-deoxy-7-phosphoheptulonate synthase. Molecular dynamics simulations of 100 ns, using GROMACS, validated the stability of drug-target interactions. Additionally, ADMET profiling aided in the selection of compounds with favorable pharmacokinetic properties and safety profile for human hosts. PBPK profiling showed that ZINC98088375 had the highest bioavailability and efficient systemic circulation. Conversely, ZINC5113880 demonstrated the lowest absorption rate (39.661%). Moreover, cirrhosis, steatosis, and renal impairment appeared to influence blood concentration of the drug, impacting bioavailability. The integrative -omics approach utilized in this study underscores the potential of computer-aided drug design and offers a rational strategy for targeted inhibitor discovery against G. vaginalis. The strategy is an attempt to address the limitations of current BV treatments, including antibiotic resistance, and pave way for the development of safer and more effective therapeutics.

Correlation between dysbiosis of vaginal microecology and endometriosis: A systematic review and meta-analysis

BACKGROUND

Endometriosis, a complex gynecological condition, involves inflammation and immune dysregulation. The vaginal microbiota, characterized by its diversity, is an integral part of the vaginal microecology-interacting with vaginal anatomy, the endocrine system, and local mucosal immunity. Imbalances in this microecology are known to precipitate various inflammatory diseases. Despite extensive research, the connection between vaginal microbiota dysbiosis and endometriosis remains a subject of debate. Our study assesses the association between vaginal microecology dysbiosis and endometriosis.

METHODS

We systematically searched major electronic databases in English, including Embase, PubMed, The Cochrane Library, MEDLINE (Ovid), BIOSIS (Ovid), China National Knowledge Infrastructure (CNKI), and Wanfang, up to August 15, 2023. Selected articles underwent screening based on predefined inclusion and exclusion criteria. Normal vaginal microecology was defined as a negative Amsel/Spiegel test or Nugent score of 0-3, or Lactobacillus predominance determined by 16S rRNA gene amplification sequencing. Deviations from this norm were classified as dysbiosis, further categorized into bacterial vaginosis (BV) and intermediate BV. Data analysis utilized Revman 5.4, with effect sizes presented as Odds Ratios (OR) and 95% Confidence Intervals (CI).

RESULTS

Out of 1081 articles, eight met the inclusion criteria. Utilizing fixed-effect models due to low heterogeneity, the analysis revealed a positive association between dysbiosis and endometriosis (OR = 1.17, 95% CI 0.81-1.70; I2 = 0%), but showed a slight negative association between normal vaginal microecology with endometriosis (OR = 0.90, 95% CI 0.55-1.46; I2 = 29%). However, the association was not significant. Subgroup and sensitivity analyses corroborated the stability of these associations.

CONCLUSION

A positive correlation exists between vaginal microecology dysbiosis and endometriosis, notably with intermediate BV. However, the mechanisms underpinning this relationship remain elusive, highlighting the need for further research to overcome limitations.

TRIAL REGISTRATION

Registration number: CRD42023445163.

Pilot Study on Next-Generation Sequencing Analysis of Vaginal Microbiota in Clinically Infertile Patients Treated with Probiotics

Background: In this investigation, we aimed to understand the influence of oral probiotic supplementation on the vaginal microbiota of women preparing for assisted reproductive technology (ART) procedures. Given the importance of a healthy microbiome for reproductive success, this study sought to explore how probiotics might alter the bacterial composition in the vaginal environment. Methods: We recruited a cohort of 30 women, averaging 37 years of age (ranging from 31 to 43 years), who were scheduled to undergo ART. Using 16S ribosomal RNA (rRNA) sequencing, we meticulously analyzed the vaginal microbiota composition before and after the administration of oral probiotic supplements. Results: Our analysis identified 17 distinct microorganisms, including 8 species of Lactobacillus. Following probiotic supplementation, we observed subtle yet notable changes in the vaginal microbiota of some participants. Specifically, there was a decrease in Gardnerella abundance by approximately 20%, and increases in Lactobacillus and Bifidobacterium by 10% and 15%, respectively. Additionally, we noted a significant reduction in the Firmicutes/Bacteroidetes (F/B) ratio in the probiotic group, indicating potential shifts in the overall bacterial composition. Conclusions: These preliminary findings suggest that oral probiotic supplementation can induce significant changes in the vaginal microbiota of middle-aged women undergoing ART, potentially improving their overall bacterial profile. Future studies should consider a larger sample size and a narrower age range to validate these results. Investigating factors related to female hormone production could also provide deeper insights. Understanding the effects of probiotics on the vaginal microbiota in patients with ovarian aging may lead to personalized interventions and better reproductive outcomes.

Inflammatory mediators in bacterial vaginosis: The role of cytokines

BV is a significant concern in women's health with a varying prevalence rate in different cities of China. The condition has been linked to the acquisition of STIs, including HIV and HPV, and can lead to infertility, adverse obstetric outcomes. We conducted a comprehensive literature search in the PubMed. The search was performed from 01/01/2018 to 01/09/2023. The following search terms were used: bacterial vaginosis and cytokine. We also manually searched the reference lists of included studies and relevant reviews to identify additional articles. The presence of Gardnerella spp. can lead to changes in cytokine levels. The immune system of the female reproductive tract consists of various immune cells and molecules that play a vital role in defending against infections. Cytokines, signaling molecules involved in immune cell recruitment and activation, have been identified as potential biomarkers for diagnosing BV and predicting STIs. Current treatments for BV primarily involve antibiotics, but there is a high recurrence rate posttreatment. BV is a complex condition that affects a significant number of women worldwide. The role of cytokines in the onset, progression, and treatment of BV offers promising avenues for future research and potential diagnostic and therapeutic advancements.

Vaginal microbiota transplantation is a truly opulent and promising edge: fully grasp its potential

Vaginal microbiota transplantation (VMT) is a cutting-edge treatment modality that has the potential to revolutionize the management of vaginal disorders. The human vagina is a complex and dynamic ecosystem home to a diverse community of microorganisms. These microorganisms play a crucial role in maintaining the health and well-being of the female reproductive system. However, when the balance of this ecosystem is disrupted, it can lead to the development of various vaginal disorders. Conventional treatments, such as antibiotics and antifungal medications, can temporarily relieve the symptoms of vaginal disorders. However, they often fail to address the underlying cause of the problem, which is the disruption of the vaginal microbiota. In recent years, VMT has emerged as a promising therapeutic approach that aims to restore the balance of the vaginal ecosystem. Several studies have demonstrated the safety and efficacy of VMT in treating bacterial vaginosis, recurrent yeast infections, and other vaginal conditions. The procedure has also shown promising results in reducing the risk of sexually transmitted infections and preterm birth in pregnant women. However, more research is needed to establish optimal donor selection, preparation, and screening protocols, as well as long-term safety and efficacy. VMT offers a safe, effective, and minimally invasive treatment option for women with persistent vaginal problems. It could improve the quality of life for millions of women worldwide and become a standard treatment option shortly. With further research and development, it could potentially treat a wide range of other health problems beyond the scope of vaginal disorders.

Impact of Genital Infections and Antibiotic Use on Incidence of Preterm Birth: A Retrospective Observational Study

This study investigates the complex interplay among genital infections, antibiotic usage, and preterm birth. This study aims to identify common genital pathogens associated with preterm births, assess the impact of various antibiotic treatments on pregnancy outcomes, and understand antibiotic resistance patterns among these pathogens. This study included 71 pregnant women who experienced preterm birth and 94 women with genital infections who delivered at term. Various maternal characteristics, medical history, signs and symptoms, gestational weight, gestational age, type of birth, vaginal pH, Nugent scores, and vaginal flora were analyzed. Antibiotic resistance patterns of isolated microorganisms were also examined. The prevalence of sexually transmitted diseases (STDs) and genital herpes was significantly higher in the preterm group. Preterm births were associated with fever, pelvic pain, vaginal spotting, and fatigue. Vaginal pH levels and Nugent scores were significantly higher in the preterm group, indicating disturbed vaginal flora. The presence of Extended-Spectrum Beta-Lactamases (ESBLs) was a particularly strong risk factor, increasing by more than four times the odds of preterm birth (OR = 4.45, p = 0.001). Vancomycin-Resistant Enterococci (VRE) presence was another critical factor, with a four-fold increase in the odds of preterm birth (OR = 4.01, p = 0.034). The overall presence of Multidrug-Resistant (MDR) organisms significantly increased the odds of preterm birth (OR = 3.73, p = 0.001). Specific pathogens like Chlamydia trachomatis (OR = 3.12, p = 0.020) and Mycoplasma hominis (OR = 3.64, p = 0.006) were also identified as significant risk factors. Ureaplasma urealyticum also showed a significantly higher risk of preterm birth (OR = 2.76, p = 0.009). This study highlights the importance of screening for and treating genital infections during pregnancy, especially STDs and genital herpes, as they can significantly increase the risk of preterm birth. Additionally, the presence of specific microorganisms and antibiotic resistance patterns plays an essential role in preterm birth risk. Early detection and targeted antibiotic treatment may help mitigate this risk and improve pregnancy outcomes.

Bacterial vaginosis testing gaps for transmasculine patients may exacerbate health disparities

Introduction

Bacterial vaginosis (BV) is associated with non-optimal changes in the vaginal microbiome and increased susceptibility to STIs and HIV in cisgender women. Much less is known about the sexual health of transmasculine people and susceptibility to BV, STIs, and HIV. This study's objective was to assess BV testing and outcomes of transmasculine and cisgender women patient populations at a large, LGBTQ + federally qualified health center.

Methods

Retrospective electronic health record data were extracted for eligible patients having at least one primary care visit between January 1, 2021, and December 31, 2021. Transmasculine patients were limited to those with a testosterone prescription in 2021. We conducted log binomial regression analysis to determine the probability of receiving a BV test based on gender identity, adjusting for sociodemographic characteristics.

Results

During 2021, 4,903 cisgender women patients and 1,867 transmasculine patients had at least one primary care visit. Compared to cisgender women, transmasculine patients were disproportionately young, White, queer, privately insured, living outside Chicago, and had a lower rate of BV testing (1.9% v. 17.3%, p < 0.001). Controlling for sociodemographics, transmasculine patients were less likely to receive a BV test [Prevalence Ratio = 0.19 (95% CI 0.13-0.27)].

Discussion

The low rate of BV testing among transmasculine patients may contribute to disparities in reproductive health outcomes. Prospective community- and provider-engaged research is needed to better understand the multifactorial determinants for sexual healthcare and gender-affirming care for transmasculine patients. In particular, the impact of exogenous testosterone on the vaginal microbiome should also be determined.

Bacterial Vaginosis (BV) and Vaginal Microbiome Disorders in Women Suffering from Polycystic Ovary Syndrome (PCOS)

Introduction: Polycystic ovary syndrome (PCOS) is a multifactorial, heterogeneous endocrine and metabolic disorder in women. Due to its association with the menstrual cycle and fertility disorders, the importance of this problem is emphasized especially in patients of reproductive age. Based on a number of analyses, the effect of PCOS on altering the diversity of the microbiome (e.g., intestinal or vaginal) is suggested. Vaginal dysbiosis can result in BV (bacterial vaginosis). The purpose of this study was to assess the prevalence of BV in patients with PCOS, as well as to determine the most reliable diagnostic factors. Material and Methods: Retrospective analysis of microbiological findings (2018-2022) of PCOS patients (n = 594) of reproductive age. The present analysis focused on the results of patients with PCOS (n = 380) and vaginal discharge with pH ≥ 4.4 and suspected BV. Biological material was a vaginal swab/vaginal secretion. The most commonly used routine methods for assessing BV were the Amsel analysis and the Nugent scoring system. Results: Patients with PCOS and vaginal fluid pH ≥ 4.4 and suspected BV (n = 380) accounted for 64% of all PCOS patients (n = 594). The relationship between pH and detection of "clue cells" showed significant dependency and increased with leukocytes. The pH measurement also showed dependency on high G. vaginalis counts. In addition, the elimination of lactic acid bacteria (LAB) in vaginal secretions was associated with an increase in the number of leukocytes with increasing pH values. A marked increase in G. vaginalis was found in more than half (56.8%) of PCOS women (n = 380) with suspected BV. No dependency was observed between the absence of LAB and the diagnosis of BV on a positive G. vaginalis culture. Of the n = 380 patients with PCOS, 191 (50%) had a Nugent score ≥ 7 positive for BV. No dependency was observed between the number of patients with Candida sp. in vaginal secretions and pH, BV (with clue cells), or elevated leukocyte levels. The LRM was adjusted and the statistical model represented by the following formula was obtained: log(p/(1 - p)) = -1.18 + 1.24 × Group4.6 + 1.08 × Group4.8 + 1.66 × Group5.4. Conclusions: Based on the present analysis, BV appears to be more common in patients with PCOS than in the non-PCOS population. Chronic inflammation in PCOS patients and abnormalities in the vaginal microbiome may predispose to the development of BV. In women with PCOS, BV may be one of the unrecognized causes of infertility or complications of pregnancy. Despite the potential link between PCOS and the development of BV, the extent to which this syndrome contributes to vaginal dysbiosis and reproductive complications requires further study.

Deciphering Intermediate Nugent scores: Utility of Real-time PCR for Bacterial Vaginosis diagnosis

PURPOSE

To optimize real-time PCR assays for diagnosis of Bacterial Vaginosis (BV) and determine cut-off loads by ROC analysis for Gardnerella vaginalis, Atopobium vaginae and Lactobacillus spp. as compared to Nugent scoring (Gold standard) in clinical samples.

RESULTS

Out of 125 women, 34 were positive, 26 intermediate and 65 negative for BV by Nugent scoring. All three real-time PCR assays were found to be highly sensitive & specific and AUC suggested excellent diagnostic accuracy. An optimal cut-off was >9.45 × 103 copies/ ml, >3.34 × 103 copies/ ml & ≤ 18.63 × 103 copies/ ml for G. vaginalis, A. vaginae and Lactobacillus spp. respectively, in BV positives. Gram staining and qPCR were discordant only in patients with intermediate scores (n = 26) where qPCR identified 15 (57.69%) as positive and 11 (42.3%) as negative.

CONCLUSION

PCR-based molecular BV diagnosis is more accurate and can be used for deciphering intermediate Nugent scores.

Exploratory study on the mechanism of necrotic effect of nourishing cells in the context of genital tract infection in premature rupture of membranes

To explore the mechanism of necrotic effect of nourishing cells in the context of genital tract infection in premature rupture of membranes (PROM). One hundred eight patients with PROM treated at our hospital from June 2020 to June 2022 were selected as the PROM group. Simultaneously, 108 cases of normal full-term pregnant women were chosen as the control group. Western blot analysis was performed to measure the relative expression levels of cysteinyl aspartate specific proteinase-1 (Caspase-1), cysteinyl aspartate specific proteinase-3 (Caspase-3), nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3), and interleukin (IL)-1β proteins, which are associated with necrosis of placental nourishing cells, in the placenta of both groups. TUNEL staining was used to detect the number of apoptotic placental nourishing cells. The differences in necrotic factors of placental nourishing cells were analyzed between full-term and preterm cases in the PROM group, as well as among patients with different genital tract infections. The apoptotic count of placental nourishing cells in the PROM group was 58.46 ± 11.26 cells/field, which was markedly higher than that of the control group (P < .05). The relative expression levels of the necrotic factors Caspase-1, Caspase-3, NLRP3, and IL-1β proteins in placental nourishing cells of the PROM group were 1.32 ± 0.26, 1.19 ± 0.30, 1.29 ± 0.28, and 1.23 ± 0.24, respectively. These values were significantly higher than those of the control group (P < .05). The relative expression levels of the necrotic factors Caspase-1, Caspase-3, NLRP3, and IL-1β proteins in placental nourishing cells were compared between full-term and preterm patients in the PROM group (P > .05). The relative expression levels of the necrotic factors Caspase-1, Caspase-3, NLRP3, and IL-1β proteins in placental nourishing cells were higher in patients with multiple genital tract infections compared to those with single infections or no infections in the PROM group (P < .05). PROM is associated with a significant upregulation of placental nourishing cell apoptosis and necrotic factors, including Caspase-1, Caspase-3, NLRP3, and IL-1β proteins. This upregulation is correlated with the presence of genital tract infections.

Development of 3D-printed vaginal devices containing metronidazole for alternative bacterial vaginosis treatment

Bacterial vaginosis (BV) is an abnormal condition caused by the change of microbiota in the vagina. One of the most common bacteria found in the case of BV is Gardnerella vaginalis, which is categorised as anaerobic facultative bacteria. Currently, the available treatment for BV is the use of antibiotics, such as metronidazole (MTZ), in topical and oral dosage forms. The limitation of the currently available treatment is that multiple administration is required and thus, the patient needs to apply the drug frequently to maintain the drug efficacy. To address these limitations, this research proposed prolonged delivery of MTZ in the form of intravaginal devices made from biodegradable and biocompatible polymers. Semi-solid extrusion (SSE) 3D printing was used to prepare the intravaginal devices. The ratio of high and low molecular weight poly(caprolactone) (PCL) was varied to evaluate the effect of polymer composition on the drug release. The versatility of SSE 3D printer was used to print the intravaginal devices into two different shapes (meshes and discs) and containing two different polymer layers made from PCL and a copolymer of methyl vinyl ether and maleic anhydride (Gantrez™-AN119), which provided mucoadhesive properties. Indeed, this layer made from Gantrez™-AN119 increased ca. 5 times the mucoadhesive properties of the final 3D-printed devices (from 0.52 to 2.57 N). Furthermore, MTZ was homogenously dispersed within the polymer matrix as evidenced by scanning electron microscopy analysis. Additionally, in vitro drug release, and antibacterial activity of the MTZ-loaded intravaginal devices were evaluated. Disc formulations were able to sustain the release of MTZ for 72 h for formulations containing 70/30 and 60/40 ratio of high molecular weight/low molecular weight PCL. On the other hand, the discs containing a 50/50 ratio of high molecular weight/low molecular weight PCL showed up to 9 days of release. However, no significant differences in the MTZ release from the MTZ-loaded meshes (60/40 and 50/50 ratio of high molecular weight/low molecular weight PCL) were found after 24 h. The results showed that the different ratios of high and low molecular weight PCL did not significantly affect the MTZ release. However, the shape of the devices did influence the release of MTZ, showing that larger surface area of the meshes provided a faster MTZ release. Moreover, MTZ loaded 3D-printed discs (5% w/w) were capable of inhibiting the growth of Gardnerella vaginalis. These materials showed clear antimicrobial properties, exhibiting a zone of inhibition of 19.0 ± 1.3 mm. Based on these findings, the manufactured represent a valuable alternative approach to the current available treatment, as they were able to provide sustained release of MTZ, reducing the frequency of administration and thus improving patient compliance.

Disposable Device for Bacterial Vaginosis Detection

Due to the increasing demand for clinical testing of infectious diseases at the point-of-care, the global market claims alternatives for rapid diagnosis tools such as disposable biosensors, avoiding the need for specialized laboratories and skilled personnel. Bacterial vaginosis (BV) is an infectious disease that commonly affects reproductive-age women and predisposes the infection of sexually transmitted diseases. Especially in asymptomatic cases, BV can lead to pelvic inflammatory conditions, postpartum endometritis, and preterm labor. Conventionally, BV diagnosis involves the microscopic analysis of vaginal swab samples; it thus requires highly trained personnel. In response, we report a novel microfluidic paper-based analytical device for BV diagnosis. Sialidase, a biomarker overexpressed in BV, was detected by exploiting an immunosensing mechanism previously discovered by our team. This technology employs a graphene oxide-coated surface as a quencher of fluorescence; the fluorescence of the immunoprobes that do not experiment immunoreactions (antibody-antigen) are deactivated by graphene oxide via non-radiative energy transfer, whereas those immunoprobes undergoing immunoreactions preserve their photoluminescence due to the distance and the low affinity between the immunocomplex and the graphene oxide-coated surface. Our paper-based test was typically carried out within 20 min, and the sample volume was 6 μL. Besides, it was tested with 14 vaginal swabs specimens to discriminate clinical samples of women with normal microbiota from those with BV. Our disposable device represents a new tool to prevent the consequences of BV.

Metabolic signature for a dysbiotic microbiome in the female genital tract: A systematic review and meta-analysis

BACKGROUND

The vaginal microbiome (VMB) is a critical determinant of reproductive health, where a microbial shift towards a dysbiotic environment has implications for susceptibility to, and clinical presentation of sexually transmitted infections (STIs). Metabolomic profiling of the vaginal microenvironment has led to the identification of metabolic responses to clinical conditions of dysbiosis. However, no studies have examined metabolic markers that are common across conditions and can serve as a signature for vaginal dysbiosis.

METHOD OF STUDY

We have conducted a comprehensive systematic review and meta-analysis to identify consistently deregulated metabolites along with their impact on host and microbial metabolism during dysbiosis. We employed two complementary approaches including a vote counting analysis for all eligible studies identified in the systematic review, in addition to a meta-analysis for a subset of studies with sufficient available data. Significantly deregulated metabolites were then selected for pathway enrichment analysis.

RESULTS

Our results revealed a total of 502 altered metabolites reported across 10 dysbiotic conditions from 16 studies. Following a rigorous, collective analysis, six metabolites which were consistently downregulated and could be generalized to all dysbiotic conditions were identified. In addition, five downregulated and one upregulated metabolite was identified from a bacterial vaginosis (BV) focused sub-analysis. These metabolites have the potential to serve as a metabolic signature for vaginal dysbiosis. Their role in eight altered metabolic pathways indicates a disruption of amino acid, carbohydrate, and energy metabolism during dysbiosis.

CONCLUSION

Based on this analysis, we propose a schematic model outlining the common metabolic perturbations associated with vaginal dysbiosis, which can be potential targets for therapeutics and prophylaxis.

Mapping the vaginal microbiota variations in women from a community clinic in Mumbai, India

PURPOSE

The vaginal microbiome contributes significantly to women's reproductive health and fluctuates due to various physiological and pathological factors. The study's objective is to map the vaginal microbiome of non-pregnant women and evaluate variations based on various potential factors influencing vaginal milieu.

METHODS

Fifty-two sexually active, non-pregnant women between 18 and 45 years were recruited from a community clinic and clinical history was recorded. Vaginal swabs were collected to assess the vaginal microbiome by sequencing the V3-V4 region of the 16S rRNA using the Illumina HiSeq platform, followed by data analysis with QIIME 2. Vaginal milieu was assessed by Nugent score and profiling cytokines in the cervico-vaginal lavage.

RESULTS

Lactobacillus iners (34.3%) were the most abundant species in all women. Significant changes in abundance of genera (Lactobacillus, Prevotella and Anaerococcus), expression of pro-inflammatory cytokine IFN-γ and changes in alpha and beta diversity was observed in women having asymptomatic bacterial vaginosis (BV). Differences in beta diversity were seen between healthy women and women exhibiting presence of Candida spp. Variations in the abundance of genera (Lactobacillus, Bifidobacterium, Porphyromonas) were observed in women who had delivery less than twelve months back, probably as more of these women (50%, 53.7%) had higher abnormal Nugent score.

CONCLUSION

Lactobacillus iners was the most prevalent vaginal species in women from a Mumbai community clinic. Maximum variations in the vaginal microbiome characterized by a perturbation of the Lactobacillus predominant vaginal microbiota are seen in those women who have asymptomatic BV and childbirth within last twelve months.

Biofilm-Forming Capacity and Drug Resistance of Different Gardnerella Subgroups Associated with Bacterial Vaginosis

Bacterial vaginosis (BV) is the most common infection of the lower reproductive tract among women of reproductive age. Recurrent infections and antibiotic resistance associated with biofilms remain significant challenges for BV treatment. Gardnerella species are commonly found in women with and without BV, indicating that genetic differences among Gardnerella isolates may distinguish pathogenic from commensal subgroups. This study isolated 11 Gardnerella strains from vaginal samples obtained from women with BV before or after treatment. The biofilm formation ability of each strain was examined by crystal violet staining. Eight strains were selected using phylogenetic analysis of the cpn60 sequences and classified as subgroups A (6/8), B (1/8), and D (1/8). The biofilm formation ability and antibiotic resistance profile of these strains was compared among the subgroups. Subgroup D had the strongest biofilm formation ability. Six of the planktonic strains exhibited resistance to the first-line BV drug, metronidazole, and one to clindamycin. Moreover, biofilm formation in vitro increased strain resistance to clindamycin. Two strains with strong biofilm ability, S20 and S23, and two with weak biofilm ability, S24 and S25, were selected for comparative genomic analysis. S20 and S23 were found to contain four key genes associated with biofilm formation and more genes involved in carbohydrate synthesis and metabolism than S24 and S25. Identifying differences in the expression of virulence factors between Gardnerella subgroups could inform the development of novel treatments for BV.

State of the Art for Diagnosis of Bacterial Vaginosis

Bacterial vaginosis (BV) is the most common cause of vaginal discharge among reproductive-age women. It is associated with multiple adverse health outcomes, including increased risk of acquisition of HIV and other sexually transmitted infections (STIs), in addition to adverse birth outcomes. While it is known that BV is a vaginal dysbiosis characterized by a shift in the vaginal microbiota from protective Lactobacillus species to an increase in facultative and strict anaerobic bacteria, its exact etiology remains unknown. The purpose of this minireview is to provide an updated overview of the range of tests currently used for the diagnosis of BV in both clinical and research settings. This article is divided into two primary sections: traditional BV diagnostics and molecular diagnostics. Molecular diagnostic assays, particularly 16S rRNA gene sequencing, shotgun metagenomic sequencing, and fluorescence in situ hybridization (FISH), are specifically highlighted, in addition to multiplex nucleic acid amplification tests (NAATs), given their increasing use in clinical practice (NAATs) and research studies (16S rRNA gene sequencing, shotgun metagenomic sequencing, and FISH) regarding the vaginal microbiota and BV pathogenesis. We also provide a discussion of the strengths and weaknesses of current BV diagnostic tests and discuss future challenges in this field of research.

Risk factors of recurrent bacterial vaginosis among women of reproductive age: A cross-sectional study

The aim of this study was to explore risk factors of recurrent bacterial vaginosis (RBV) among women of reproductive age. This cross-sectional study was carried out in real-world conditions. Women with RBV were selected, and simultaneously uncomplicated bacterial vaginosis (UBV) and those who underwent routine gynecological examination and had normal vaginal microflora were also recruited as the control. Totally, 316 participants were enrolled. Univariate analysis showed that unemployment, desserts, and wiping were related to UBV, while there was no definite relationship between education, high body mass index, smoking, sedentary lifestyle, and RBV or UBV. History of human papillomavirus infection, contraceptive methods, age at first sexual intercourse, and not cleaning vulva during sexual activity were connected with UBV, while the history of other vaginitis and number of sexual partners in the previous year were related to both RBV and UBV. Multivariate logistic regression analysis revealed that lower educational level increased the risk of suffering RBV. Interestingly, no smoking was a protective factor. Moreover, the absence of other vaginitis and an exclusive sexual partner could also weaken the risk of incurring RBV. These various adverse factors alter endocrine function and vaginal immunity, further leading to the recurrence of BV. It is necessary to take corresponding measures to avoid risk factors and to help lessening the prevalence of RBV among women of reproductive age.

Single-Molecule Approach to 16S rRNA for Vaginal Microbiome Signatures in Response to Metronidazole Treatment

Bacterial vaginosis (BV) is the most common infection of the lower reproductive tract among women of reproductive age, characterized by a depletion of health-associated Lactobacillus and an overgrowth of anaerobes. Metronidazole has been recommended as a first-line therapy for treating BV for decades. Although most cases are cured by the treatment, recurrent infections of BV seriously affect women's reproductive health. Until now, limited information on the vaginal microbiota has been explored at the species level. Here, we adopted a single molecular sequencing approach for the 16S rRNA gene, named FLAST (full-length assembly sequencing technology), to analyze the human vaginal microbiota that improved species-level resolution for taxonomy and identified microbiota alterations in the vaginal tract in response to treatment with metronidazole. Appling high-throughput sequencing, we identified 96 and 189 novel full-length 16S rRNA gene sequences in Lactobacillus and Prevotella, respectively, which had not previously been reported in vaginal samples. Moreover, we found that Lactobacillus iners was significantly enriched in the cured group before metronidazole treatment, and that was maintained in a high frequency after the treatment, suggesting an important role for this species in response to metronidazole treatment. Our research also highlights the importance of the single-molecule paradigm for progressing the field of microbiology and applying these insights to better understand the dynamic microbiota during BV treatment. Subsequent novel treatment approaches should be proposed to improve BV treatment outcomes, optimize the vaginal microbiome, and reduce gynecological and obstetric sequelae. IMPORTANCE Bacterial vaginosis (BV) is a common infectious disease of the reproductive tract. Metronidazole treatment, as the first line of treatment, frequently fails at recovery of the microbiome. However, the precise types of Lactobacillus and other bacteria involved in BV remain unclear, and this has resulted in a failure to identify potential markers to predict clinic outcomes. In this study, we adopted a 16S rRNA gene full-length assembly sequencing technology for the taxonomy analysis and evaluation of vaginal microbiota before and after treatment with metronidazole. We additionally identified 96 and 189 novel 16S rRNA gene sequences in Lactobacillus and Prevotella species, respectively, in vaginal samples, which improves our understanding of the vaginal microbiota. Moreover, we found that the abundance of Lactobacillus iners and Prevotella bivia before treatment was associated with a lack of cure. These potential biomarkers will help to facilitate future studies aimed at improving BV treatment outcomes, optimize the vaginal microbiome, and reduce adverse sexual and reproductive outcomes.

Pre- and Postnatal Determinants Shaping the Microbiome of the Newborn in the Opinion of Pregnant Women from Silesia (Poland)

Pre- and postnatal factors influence the formation of the newborn's microbiome as early as birth and the intrauterine period has a substantial impact on the composition of the baby's gastrointestinal microbiota and its subsequent development. This study intends to measure pregnant women's knowledge of the importance of microbiota for the health of the newborn. The sample was selected based on defined inclusion and exclusion criteria. The assessment of women's knowledge was assessed by the Kolmogorov-Smirnov and Kruskal-Wallis statistical tests. This study population comprised 291 adult pregnant women with a mean age of 28.4 ± 4.7 years. A total of 34% (n = 99), 35% (n = 101), and 31.3% (n = 91) were at the 1-3 trimester, respectively. The results showed that 36.4% of the women were aware that the intrauterine period changes the makeup of the gastrointestinal microbiota, whereas 5.8% exhibited awareness of the composition of the child's normal gut microbiota. Most of the women surveyed-(72.1%)-know that colonization of the tract occurs as early as the birth period. Women with student status (those who will pursue higher education in the future) and those who had given birth to the most children exhibited higher levels of knowledge.

Advanced Organotypic In Vitro Model Systems for Host-Microbial Coculture

In vitro model systems have been advanced to recapitulate important physiological features of the target organ in vivo more closely than the conventional cell line cultures on a petri dish. The advanced organotypic model systems can be used as a complementary or alternative tool for various testing and screening. Numerous data from germ-free animal studies and genome sequencings of clinical samples indicate that human microbiota is an essential part of the human body, but current in vitro model systems rarely include them, which can be one of the reasons for the discrepancy in the tissue phenotypes and outcome of therapeutic intervention between in vivo and in vitro tissues. A coculture model system with appropriate microbes and host cells may have great potential to bridge the gap between the in vitro model and the in vivo counterpart. However, successfully integrating two species in one system introduces new variables to consider and poses new challenges to overcome. This review aims to provide perspectives on the important factors that should be considered for developing organotypic bacterial coculture models. Recent advances in various organotypic bacterial coculture models are highlighted. Finally, challenges and opportunities in developing organotypic microbial coculture models are also discussed.

Bacterial Vaginosis and Post-Operative Pelvic Infections

Bacterial vaginosis (BV) represents a condition in which the normal protective Lactobacilli, especially those that produce H₂O₂, are replaced by high quantities of facultative anaerobes, leading to gynecologic and obstetric post-operative complications. BV is an important cause of obstetric and gynecological adverse sequelae and it could lead to an increased risk of contracting sexually transmitted infections such as gonorrhea, genital herpes, Chlamydia, Trichomonas, and human immunodeficiency virus. Herein, we reviewed bacterial vaginosis and its association with post-operative pelvic infections. In Obstetrics, BV has been associated with increased risk of preterm delivery, first-trimester miscarriage in women undergoing in vitro fertilization, preterm premature rupture of membranes, chorioamnionitis, amniotic fluid infections, postpartum and postabortal endomyometritis as well as postabortal pelvic inflammatory disease (PID). In gynecology, BV increases the risk of post-hysterectomy infections such as vaginal cuff cellulitis, pelvic cellulitis, pelvic abscess, and PID. BV is often asymptomatic, can resolve spontaneously, and often relapses with or without treatment. The American College of Obstetricians and Gynecologists recommends testing for BV in women having an increased risk for preterm delivery. Women with symptoms should be evaluated and treated. Women with BV undergoing gynecological surgeries must be treated to reduce the frequency of post-operative pelvic infections. Metronidazole and clindamycin are the mainstays of therapy. Currently, there is no consensus on pre-surgery screening for BV; decisions are made on a case-by-case basis.

Systemic, Mucosal Immune Activation and Psycho-Sexual Health in ART-Suppressed Women Living with HIV: Evaluating Biomarkers and Environmental Stimuli

Gender medicine is now an approach that can no longer be neglected and must be considered in scientific research. We investigated the systemic and mucosal immune response in a population of women living with HIV (WLWH) who were receiving successful ART and the sexual and psychological repercussions of HIV infection on the women's health. As control group, healthy women (HW) matched for age and sex distribution, without any therapy, were included. In summary, our study highlighted the persistence of immune-inflammatory activation in our population, despite virological suppression and a normal CD4 cell count. We found a hyperactivation of the systemic monocyte and an increase in inflammatory cytokine concentrations at the systemic level. The analysis carried out showed a significantly higher risk of HPV coinfection in WLWH compared to HW. Furthermore, our data revealed that WLWH have a profile compatible with sexual dysfunction and generalized anxiety disorders. Our study underlines that patients living with HIV should be evaluated by multidisciplinary teams. These findings also support the idea that more and different immunological markers, in addition to those already used in clinical practice, are needed. Further studies should be carried out to clarify which of these could represent future therapy targets.

Association between bacterial vaginosis and 25-Hydroxy vitamin D: a case-control study

INTRODUCTION

Bacterial vaginosis (BV) is the most common vaginal dysbiosis among women of reproductive age. Micronutrient deficiencies, including vitamin D deficiency, can increase the risk of BV. The findings of previous studies regarding the relationship between vitamin D deficiency and BV were conflicting. Therefore, this study aimed to evaluate the association between BV and serum level of 25-hydroxy vitamin D.

MATERIALS AND METHODS

This case-control study was conducted in Gonabad County in 2021. One hundred and twenty-five confirmed BV cases and 125 controls who were matched based on age and intercourse frequency (maximum difference of two days per week) enrolled in the study. Data collection was performed using a demographic and reproductive data questionnaire and a checklist for recording Whiff test results, serum 25-hydroxy vitamin D level, litmus paper observation, and microscopic findings (clue cells). Serum level of vitamin D was evaluated based on enzyme-linked immunoassay method (Monobind kit) from 0.5 ml venous blood drawn from each participant. The conditional logistic regression model was used to analyze data.

RESULTS

The BV cases had significantly lower 25-hydroxy vitamin D serum levels than controls. The odds of BV increased with vitamin D deficiency (Adjusted odds ratio (AOR): 4.34, 95% confidence interval (CI): 1.39-13.4, p = 0.011, FDR q-value = 0.051), vitamin D insufficiency (AOR: 3.65, 95% CI: 1.23-10.85; p = 0.020; FDR q-value = 0.053), cigarette/hookah smoking (AOR: 3.65, 95% CI: 1.23, 10.85; p = 0.020; FDR q-value = 0.053) and lower age at first intercourse (AOR: 1.16, 95% CI: 1.05, 1.28; p = 0.004; FDR q-value = 0.048). The odds of BV was 0.80 and 0.78 times lower in participants who had coitus interruptus (AOR: 0.20, 95% CI: 0.06, 0.63; p = 0.006; FDR q-value = 0.048) and condom use (AOR: 0.28, 95% CI: 0.10, 0.79; p = 0.016; FDR q-value = 0.051), respectively, compared to participants who did not use contraceptives.

CONCLUSION

These findings suggested that lower serum vitamin D levels were associated with an increased risk of developing BV. However, further studies are needed to confirm the results of the present study.

Lactobacillus helveticus HY7801 ameliorates bacterial vaginosis by inhibiting biofilm formation and epithelial cell adhesion of Gardnerella vaginalis

Bacterial vaginosis (BV) is caused by a microbial imbalance in the vaginal ecosystem, which causes genital discomfort and a variety of potential complications in women. This study validated the potential of Lactobacillus helveticus HY7801 as a probiotic to benefit vaginal health. In vivo, HY7801 reduced the number of Gardnerella vaginalis (GV) and pro-inflammatory cytokines in the vagina of GV-induced BV mice and ameliorated vaginal histological changes. In vitro, HY7801 exhibited positive resistance to simulated gastrointestinal conditions, showed excellent adherence ability to the female genital epithelium, and had high lactic acid and H₂O₂ production capacity. Furthermore, it was found that HY7801 can alleviate BV because it can suppress the expression of virulence factor genes of GV involved in epithelial cell adhesion and biofilm formation along with antibacterial activity against GV. These results indicate that HY7801 can be used as a promising probiotic strain for the maintenance of a healthy vaginal physiological state.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01208-7.

An Integrative Review of the Relationship Between Intrauterine Devices and Bacterial Vaginosis

OBJECTIVE

To examine the relationship between intrauterine devices (IUDs) and bacterial vaginosis (BV) through an integrative review of the current literature.

DATA SOURCES

CINAHL, MEDLINE, Health Source, Evidence-Based Medicine's Cochrane Central Registry of Controlled Trials, Embase, and Web of Science databases were searched.

STUDY SELECTION

Cross-sectional, case-control, cohort, quasi-experimental, and randomized controlled trials examining copper (Cu-IUD) and levonorgestrel (LNG-IUD) use in reproductive- age users with BV occurrence confirmed with Amsel's criteria or Nugent scoring were included. Articles included were published in the past 10 years.

DATA EXTRACTION

Fifteen studies met criteria, after an initial search identified 1,140 potential titles, and two reviewers assessed 62 full-text articles for inclusion.

DATA SYNTHESIS

Data were categorized into three groups: retrospective descriptive cross-sectional studies identifying point prevalence of BV among IUD users; prospective analytic studies examining BV incidence and prevalence among Cu-IUD users; and prospective analytic studies examining BV incidence and prevalence among LNG-IUD users.

CONCLUSION

Synthesis and comparison of studies were difficult because of disparate study designs, sample sizes, comparator groups, and inclusion criteria for individual studies. Synthesis of data from cross-sectional studies showed that all IUD users combined may have an increased point prevalence of BV compared with non-IUD users. These studies did not delineate LNG-IUDs from Cu-IUDs. Findings from cohort and experimental studies suggest a possible increase in BV occurrence among Cu-IUD users. Evidence is lacking to show an association between LNG-IUD use and BV.

Maternal and fetal outcomes of pregnant women with bacterial vaginosis

Background

Bacterial vaginosis (BV) is a common infection in women of reproductive age group because of vaginal dysbiosis. The impact of BV during pregnancy is still not well defined. The objective of this study is to assess the maternal-fetal outcome in women with BV.

Materials and Methods

A prospective cohort study over one-year duration was conducted from December, 2014 until December, 2015, involving 237 women who presented with abnormal vaginal discharge, preterm labour or preterm prelabour rupture of membrane between 22- and 34-weeks period of gestation. Vaginal swabs were sent for culture and sensitivity, BV® Blue testing and PCR for Gardnerella vaginalis (GV).

Results

BV was diagnosed in 24/237 (10.1%) cases. The median gestational age was 31.6 weeks. GV was isolated from 16 out of 24 (66.7%) in the BV positive group. There was a significantly higher preterm birth rate, below 34 weeks (22.7% vs. 6.2%, p = 0.019) in women with BV. There was no statistically significant difference in maternal outcome such as clinical chorioamnionitis or endometritis. However, placental pathology revealed more than half (55.6%) of women with BV had histologic chorioamnionitis. Neonatal morbidity was significantly higher with exposure to BV, with a lower median birth weight, higher rate of neonatal intensive care unit admission (41.7% vs. 19.0%, p = 0.010), increased intubation for respiratory support (29.2% vs. 7.6%, p = 0.004) and respiratory distress syndrome (33.3% vs. 9.0%, p = 0.002).

Conclusion

More research is needed to formulate guidelines for prevention, early detection and treatment of BV during pregnancy to reduce intrauterine inflammation and the associated adverse fetal outcomes.

Review of the evidence of the effects of human papillomavirus infection and Gardnerella vaginalis, and their co-infection on infertility

A prevalent sexually transmitted infection, the human papillomavirus (HPV) is typically obtained just after the first sexual activity. The majority of HPV infections are asymptomatic and temporary. Cervical, anal, penile, vaginal, vulvar, and oropharyngeal cancers can occur due to recurrent infections with high-risk (hr)-HPV strains, generally decades later. Infections with HPV are significantly associated with reproductive function abnormalities. Per recent research, HPV infections may result in male infertility by reducing sperm motility. The hr-HPV infection was a risk factor for miscarriage, and the indiscriminate HPV genotype increased the probability of premature labor unexpectedly. Women's endometrial trophoblastic cell implantation is decreased by HPV. Gardnerella vaginalis (GV), an anaerobic bacterium that is a component of the natural vaginal flora, can be associated with bacterial vaginosis (BV) when it starts to overgrow and emerge as the dominant species. Reduced Lactobacillus species abundance and GV are linked to female infertility. Data from in vitro studies suggests that sialidase produced by GV may facilitate the entry and growth of papilloma and other sexually transmitted viruses. Also, based on some studies conducted in the past, it can be said that GV and BV are associated with the development of uterine cancer. However, there is still not enough information about the exact mechanism of GV and HPV in causing infertility, which requires more research.

Detect feature edges for diagnosis of bacterial vaginosis

One of the most common diseases among women of reproductive age is bacterial vaginosis (BV). However, the etiology of BV remains unknown. In this study, we modeled the temporal sample of the vaginal microbiome as a network and investigated the relationship between the network edges and BV. Furthermore, we used feature selection algorithms including decision tree (DT) and ReliefF (RF) to select the network feature edges associated with BV and subsequently validated these feature edges through logistic regression (LR) and support vector machine (SVM). The results show that: machine learning can distinguish vaginal community states (BV, ABV, SBV, and HEA) based on a few feature edges; selecting the top five feature edges of importance can achieve the best accuracy for the feature selection and classification model; the feature edges selected by DT outperform those selected by RF in terms of classification algorithm LR and SVM, and LR with DT feature edges is more suitable for diagnosing BV; two feature selection algorithms exhibit differences in the importance of ranking of edges; the feature edges selected by DT and RF cannot construct sub-network associated with BV. In short, the feature edges selected by our method can serve as indicators for personalized diagnosis of BV and aid in the clarification of a more mechanistic interpretation of its etiology.

HEALTHCARE-ASSOCIATED BACTERIAL VAGINOSIS AFTER GYNECOLOGICAL SURGERIES AND ASSOCIATED ADVERSE PREGNANCY OUTCOME IN UKRAINE

OBJECTIVE

The aim: To determine the prevalence of healthcare-associated bacterial vaginosis after gynecological surgeries and associated adverse pregnancy outcomes in Ukraine.

PATIENTS AND METHODS

Materials and methods: Multicenter retrospective cohort study was conducted from January 2019 to December 2021 in eleven medical centers from eight regions of Ukraine. Vaginal cultures were obtained preoperatively from 3,502 women undergoing gynecologic surgery. Diagnosis of Bacterial Vaginosis is based on the Nugent and Amsel criteria.

RESULTS

Results: Healthcare-associated bacterial vaginosis (HA BV) was diagnosed in 1,498 of 3,502 women, giving a prevalence rate of 42.8%. HA BV was significantly associated with preterm birth (risk ratio [RR], 2.68; 95% confidence interval [CI], 1.44-4.98), miscarriage (RR, 6.11; 95% CI, 3.22-14.11), low birth weight (RR, 3.20; 95% CI, 1.29-7.94), and premature rupture of membranes (RR, 6.75; 95% CI, 3.11-14.67).

CONCLUSION

Conclusions: The HA BV after gynecological surgeries prevalence is high in Ukraine, with a concomitant adverse pregnancy outcome, including preterm birth, low birth weight, premature rupture of membranes, and miscarriage. A significant number of cases of bacterial vaginosis are associated with long-term use of antibiotics to treat post-operative infections.

High-Throughput Sequencing-Based Analysis of Changes in the Vaginal Microbiome during the Disease Course of Patients with Bacterial Vaginosis: A Case-Control Study

Background: The vaginal microbiome is closely associated with the onset and recurrence of bacterial vaginosis (BV). In the present study, the state of vaginal microbiota during the onset and post-treatment asymptomatic stages of BV were compared to that of a healthy population to evaluate the changes in different characteristic bacteria during the onset, progression, and remission of BV. Methods: A case−control study was performed to explore these changes. Women with clinical symptoms of BV were divided into the disease group (M) and case−control group (C) based on the Nugent score. Subjects in the disease group whose symptoms were resolved after the treatment were assigned to the treated group (T) and healthy subjects were recruited into the normal control (N) group. The V3−V4 hypervariable regions of bacterial 16S rRNA genes were sequenced on the Illumina MiSeq platform. Results: The N harbored the highest number of detected species and a higher abundance of microbiota; they had a significantly higher abundance of Lactobacillus and different bacterial community composition compared to the other three groups. In group M, Gardnerella vaginalis was the dominant species, whereas Lactobacillus iners was predominant in the other three groups. While Lactobacillus was more commonly present in Group C compared to group M. it was significantly increased in group T. Alpha diversity analysis of bacterial communities revealed significant differences in community richness and diversity among all four groups (p < 0.05). Significant differences in the distribution of various bacterial communities among the different groups were also observed (p < 0.05). Specifically, the abundance of eight bacterial taxa (Megasphaera, Aerococcus christensenii, Clostridiales, Gardnerella, Peptostreptococcus, Veillonellaceae, Akkermansia, Coriobacteriales) differed significantly among the four groups (p < 0.05). Conclusion: Significant differences in the composition and alpha diversity of the vaginal microbiota at different stages of BV and the distribution of bacterial communities were observed among the investigated groups. In addition to Gardnerella, Sneathia sanguinegens and Prevotella timonensis play an important role in the pathogenesis of BV. The appearance of BV-like clinical symptoms was closely associated with the decrease in Prevotella and Atopobium vaginae populations.

Vaginal microbiome-host interactions modeled in a human vagina-on-a-chip

BACKGROUND

A dominance of non-iners Lactobacillus species in the vaginal microbiome is optimal and strongly associated with gynecological and obstetric health, while the presence of diverse obligate or facultative anaerobic bacteria and a paucity in Lactobacillus species, similar to communities found in bacterial vaginosis (BV), is considered non-optimal and associated with adverse health outcomes. Various therapeutic strategies are being explored to modulate the composition of the vaginal microbiome; however, there is no human model that faithfully reproduces the vaginal epithelial microenvironment for preclinical validation of potential therapeutics or testing hypotheses about vaginal epithelium-microbiome interactions.

RESULTS

Here, we describe an organ-on-a-chip (organ chip) microfluidic culture model of the human vaginal mucosa (vagina chip) that is lined by hormone-sensitive, primary vaginal epithelium interfaced with underlying stromal fibroblasts, which sustains a low physiological oxygen concentration in the epithelial lumen. We show that the Vagina Chip can be used to assess colonization by optimal L. crispatus consortia as well as non-optimal Gardnerella vaginalis-containing consortia, and to measure associated host innate immune responses. Co-culture and growth of the L. crispatus consortia on-chip was accompanied by maintenance of epithelial cell viability, accumulation of D- and L-lactic acid, maintenance of a physiologically relevant low pH, and down regulation of proinflammatory cytokines. In contrast, co-culture of G. vaginalis-containing consortia in the vagina chip resulted in epithelial cell injury, a rise in pH, and upregulation of proinflammatory cytokines.

CONCLUSION

This study demonstrates the potential of applying human organ chip technology to create a preclinical model of the human vaginal mucosa that can be used to better understand interactions between the vaginal microbiome and host tissues, as well as to evaluate the safety and efficacy of live biotherapeutics products. Video Abstract.