Crosstalk between Vaginal Microbiome and Female Health: A review

Altered vaginal cervical microbiota diversity contributes to HPV-induced cervical cancer via inflammation regulation

Background

Cancer has surpassed infectious diseases and heart ailments, taking the top spot in the disease hierarchy. Cervical cancer is a significant concern for women due to high incidence and mortality rates, linked to the human papillomavirus (HPV). HPV infection leads to precancerous lesions progressing to cervical cancer. The cervix's external os, near the vagina, hosts various microorganisms. Evidence points to the link between vaginal microbiota and HPV-induced cervical cancer. Cervical cancer onset aligns with an imbalanced Th1/Th2 immune response, but the role of vaginal microbiota in modulating this imbalance is unclear.

Methods

In this study, we collected vaginal samples from 99 HPV-infected patients across varying degrees of lesions, alongside control groups. These samples underwent bacterial DNA sequencing. Additionally, we employed Elisa kits to quantify the protein expression levels of Th1/Th2 cytokines IL2, IL12, IL5, IL13, and TNFa within the centrifuged supernatant of vaginal-cervical secretions from diverse research subjects. Subsequently, correlation analyses were conducted between inflammatory factors and vaginal microbiota.

Results

Our findings highlighted a correlation between decreased Lactobacillus and increased Gardenerella presence with HPV-induced cervical cancer. Functionally, our predictive analysis revealed the predominant enrichment of the ABC transporter within the vaginal microbiota of cervical cancer patients. Notably, these microbiota alterations exhibited correlations with the production of Th1/Th2 cytokines, which are intimately tied to tumor immunity.

Conclusions

This study suggests the potential involvement of vaginal microbiota in the progression of HPV-induced cervical cancer through Th1/Th2 cytokine regulation. This novel insight offers a fresh perspective for early cervical cancer diagnosis and future prevention strategies.

From whole genomes to probiotic candidates: A study of potential lactobacilli strains selection for vaginitis treatment

Vaginitis, characterized by pathogenic invasion and a deficiency in beneficial lactobacilli, has recognized lactobacilli supplementation as a novel therapeutic strategy. However, due to individual differences in vaginal microbiota, identifying universally effective Lactobacillus strains is challenging. Traditional methodologies for probiotic selection, which heavily depend on extensive in vitro experiments, are both time-intensive and laborious. The aim of this study was to pinpoint possible vaginal probiotic candidates based on whole-genome screening. We sequenced the genomes of 98 previously isolated Lactobacillus strains, annotating their genes involved in probiotic metabolite biosynthesis, adherence, acid/bile tolerance, and antibiotic resistance. A scoring system was used to assess the strains based on their genomic profiles. The highest-scoring strains underwent further in vitro evaluation. Consequently, two strains, Lactobacillus crispatus LG55-27 and Lactobacillus gasseri TM13-16, displayed an outstanding ability to produce d-lactate and adhere to human vaginal epithelial cells. They also showed higher antimicrobial activity against Gardnerella vaginalis, Escherichia coli, Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa compared to reference Lactobacillus strains. Their resilience to acid and bile environments highlights the potential for oral supplementation. Oral and vaginal administration of these two strains were tested in a bacterial vaginosis (BV) rat model at various doses. Results indicated that combined vaginal administration of these strains at 1 × 106 CFU/day significantly mitigated BV in rats. This research offers a probiotic dosage guideline for vaginitis therapy, underscoring an efficient screening process for probiotics using genome sequencing, in vitro testing, and in vivo BV model experimentation.

Role of the Gut Microbiota-Brain Axis in Brain Damage in Preterm Infants

The greatest repository of microbes in the human body, the intestinal microbiome, is involved in neurological development, aging, and brain illnesses such as white matter injury (WMI) in preterm newborns. Intestinal microorganisms constitute a microbial gut-brain axis that serves as a crucial conduit for communication between the gut and the nervous system. This axis controls inflammatory cytokines, which in turn influence the differentiation of premyelinating oligodendrocytes (pre-OLs) and influence the incidence of WMI in premature newborns through the metabolites generated by gut microbes. Here, we describe the effects of white matter injury (WMI) on intestinal dysbiosis and gut dysfunction and explain the most recent research findings on the gut-brain axis in both humans and animals. We also emphasize the delicate relationship that exists between the microbiota and the brain following acute brain injury. The role that the intestinal microflora plays in influencing host metabolism, the immune system, brain health, and the course of disease is becoming increasingly clear, but there are still gaps in the field of WMI treatment. Thus, this review demonstrates the function of the gut microflora-brain axis in WMI and elucidates the possible mechanisms underlying the communication between gut bacteria and the developing brain via the gut-brain axis, potentially opening up new avenues for microbial-based intervention and treatment for preterm WMI.

Effect of Vaginal Microecological Alterations on Female Pelvic Organ Prolapse

INTRODUCTION AND HYPOTHESIS

The objective was to investigate the correlation between endogenous vaginal microecological alterations and female pelvic organ prolapse (POP).

METHODS

Patients who underwent vaginal hysterectomy were retrospectively analyzed as the POP group (n = 30) and the non-POP group (n = 30). The vaginal microbial metabolites and enzyme levels were tested using the dry chemoenzymatic method. The mRNA and protein expression were tested using real-time quantitative PCR and immunohistochemistry. SPSS version 25.0 and GraphPad Prism 8.0 were performed for statistical analysis.

RESULTS

Compared with the non-POP group, the vaginal pH, H2O2 positivity and leukocyte esterase positivity were higher in patients with POP (all p < 0.05). Further analysis showed that patients with pelvic organ prolapse quantification (POP-Q) stage IV had higher rates of vaginal pH, H2O2 positivity and leukocyte esterase positivity than those with POP-Q stage III. Additionally, the mRNA expression of decorin (DCN), transforming growth factor beta 1 (TGF-β1), and matrix metalloproteinase-3 (MMP-3) in uterosacral ligament tissues were higher, whereas collagen I and III were lower. Similarly, the positive expression of MMP-3 in uterosacral ligament tissue was significantly upregulated in the POP group compared with the non-POP group (p = 0.035), whereas collagen I (p = 0.004) and collagen III (p = 0.019) in uterosacral ligament tissue were significantly downregulated in the POP group. Correlation analysis revealed that there was a significant correlation between vaginal microecology and collagen metabolism. In addition, MMP-3 correlated negatively with collagen I and collagen III (p = 0.002, r = -0.533; p = 0.002, r = -0.534 respectively), whereas collagen I correlated positively with collagen III (p = 0.001, r = 0.578).

CONCLUSIONS

Vaginal microecological dysbiosis affects the occurrence of female POP, which could be considered a novel therapeutic option.

Multiomics insights into the female reproductive aging

The human female reproductive lifespan significantly diminishes with age, leading to decreased fertility, reduced fertility quality and endocrine function disorders. While many aspects of aging in general have been extensively documented, the precise mechanisms governing programmed aging in the female reproductive system remain elusive. Recent advancements in omics technologies and computational capabilities have facilitated the emergence of multiomics deep phenotyping. Through the application and refinement of various high-throughput omics methods, a substantial volume of omics data has been generated, deepening our comprehension of the pathogenesis and molecular underpinnings of reproductive aging. This review highlights current and emerging multiomics approaches for investigating female reproductive aging, encompassing genomics, epigenomics, transcriptomics, proteomics, metabolomics, and microbiomics. We elucidate their influence on fundamental cell biology and translational research in the context of reproductive aging, address the limitations and current challenges associated with multiomics studies, and offer a glimpse into future prospects.

Vaginal douching and health risks among young women

Objective

Vaginal douching is practiced by women for various reasons. Studies have shown that this practice can upset the normal vaginal flora, increasing susceptibility to certain sexually transmitted diseases (STIs). This study aimed to assess the health risks associated with this practice among women aged 15-54 years in a densely populated community in Kumasi, the second capital city of Ghana.

Methods

A cross-sectional survey was conducted to gather data on the prevalence of vaginal douching among young women and their beliefs, motivations, and knowledge about the practice. A structured questionnaire was used in recruiting participants. One-hundred and fifteen structured questionnaires were administered to women aged between 15 and 54 after their consent was sought.

Results

The study established that more than half of the participants (69.6%) engaged in douching with a midpoint of 19.5. The study indicated no significant difference between the age of participants and douching (p < 0.93). However, there was an indication of a significant association between educational status, marital status, and perception in relation to douching (p < 0.003, 0.0015, and 0.00, respectively), which also influenced the frequency of douching and contraction of STIs.

Conclusion

Most women in the study community recruited, regardless of their educational and marital status, believed that douching is necessary and considered part of feminine hygiene practices. Practicing douching may lead to most health complications including pelvic inflammatory disease and infertility which must be given serious attention by researchers, health personnel, and various women's groups.

Instant Candida albicans Detection Using Ultra-Stable Aptamer Conjugated Gold Nanoparticles

Fungal pathogens such as Candida albicans have significant impacts on women's health and the economy worldwide. Current detection methods often require access to laboratory facilities that are costly, inconvenient, and slow to access. This often leads to self-diagnosis, self-treatment and eventual antifungal resistance. We have created a rapid (within five minutes), cost-effective, and user-friendly method for the early detection of Candida albicans. Our platform utilises aptamer-tagged-gold-core-shell nanoparticles for Candida albicans detection based on the presence of 1,3-β-d glucan molecules. Nanoparticle aggregation occurs in the presence of Candida albicans fungal cells, causing a redshift in the UV-visible absorbance, turning from pink/purple to blue. This colour change is perceptible by the naked eye and provides a "yes"/"no" result. Our platform was also capable of detecting Candida albicans from individual yeast colonies without prior sample processing, dilution or purification. Candida albicans yeast cells were detected with our platform at concentrations as low as 5 × 105 cells within a 50 μL sample volume. We believe that this technology has the potential to revolutionise women's health, enabling women to test for Candida albicans accurately and reliably from home. This approach would be advantageous within remote or developing areas.

Metatranscriptomic characterization of six types of forensic samples and its potential application to body fluid/tissue identification: A pilot study

Microorganisms are potential markers for identifying body fluids (venous and menstrual blood, semen, saliva, and vaginal secretion) and skin tissue in forensic genetics. Existing published studies have mainly focused on investigating microbial DNA by 16 S rRNA gene sequencing or metagenome shotgun sequencing. We rarely find microbial RNA level investigations on common forensic body fluid/tissue. Therefore, the use of metatranscriptomics to characterize common forensic body fluids/tissue has not been explored in detail, and the potential application of metatranscriptomics in forensic science remains unknown. Here, we performed 30 metatranscriptome analyses on six types of common forensic sample from healthy volunteers by massively parallel sequencing. After quality control and host RNA filtering, a total of 345,300 unigenes were assembled from clean reads. Four kingdoms, 137 phyla, 267 classes, 488 orders, 985 families, 2052 genera, and 4690 species were annotated across all samples. Alpha- and beta-diversity and differential analysis were also performed. As a result, the saliva and skin groups demonstrated high alpha diversity (Simpson index), while the venous blood group exhibited the lowest diversity despite a high Chao1 index. Specifically, we discussed potential microorganism contamination and the "core microbiome," which may be of special interest to forensic researchers. In addition, we implemented and evaluated artificial neural network (ANN), random forest (RF), and support vector machine (SVM) models for forensic body fluid/tissue identification (BFID) using genus- and species-level metatranscriptome profiles. The ANN and RF prediction models discriminated six forensic body fluids/tissue, demonstrating that the microbial RNA-based method could be applied to BFID. Unlike metagenomic research, metatranscriptomic analysis can provide information about active microbial communities; thus, it may have greater potential to become a powerful tool in forensic science for microbial-based individual identification. This study represents the first attempt to explore the application potential of metatranscriptome profiles in forensic science. Our findings help deepen our understanding of the microorganism community structure at the RNA level and are beneficial for other forensic applications of metatranscriptomics.

Microbiota dynamics, metabolic and immune interactions in the cervicovaginal environment and their role in spontaneous preterm birth

Differences in the cervicovaginal microbiota are associated with spontaneous preterm birth (sPTB), a significant cause of infant morbidity and mortality. Although establishing a direct causal link between cervicovaginal microbiota and sPTB remains challenging, recent advancements in sequencing technologies have facilitated the identification of microbial markers potentially linked to sPTB. Despite variations in findings, a recurring observation suggests that sPTB is associated with a more diverse and less stable vaginal microbiota across pregnancy trimesters. It is hypothesized that sPTB risk is likely to be modified via an intricate host-microbe interactions rather than due to the presence of a single microbial taxon or broad community state. Nonetheless, lactobacilli dominance is generally associated with term outcomes and contributes to a healthy vaginal environment through the production of lactic acid/maintenance of a low pH that excludes other pathogenic microorganisms. Additionally, the innate immunity of the host and metabolic interactions between cervicovaginal microbiota, such as the production of bacteriocins and the use of proteolytic enzymes, exerts a profound influence on microbial populations, activities, and host immune responses. These interplays collectively impact pregnancy outcomes. This review aims to summarize the complexity of cervicovaginal environment and microbiota dynamics, and associations with bacterial vaginosis and sPTB. There is also consideration on how probiotics may mitigate the risk of sPTB and bacterial vaginosis.

Maternal vitamin D-related metabolome and offspring risk of asthma outcomes

BACKGROUND

Gestational vitamin D deficiency is implicated in development of respiratory diseases in offspring, but the mechanism underlying this relationship is unknown.

OBJECTIVE

We sought to study the link between gestational vitamin D exposure and childhood asthma phenotypes using maternal blood metabolomics profiling.

METHODS

Untargeted blood metabolic profiles were acquired using liquid chromatography-mass spectrometry at 1 week postpartum from 672 women in the Copenhagen Prospective Studies on Asthma in Childhood2010 (COPSAC2010) mother-child cohort and at pregnancy weeks 32 to 38 from 779 women in the Vitamin D Antenatal Asthma Reduction Trial (VDAART) mother-child cohort. In COPSAC2010, we employed multivariate models and pathway enrichment analysis to identify metabolites and pathways associated with gestational vitamin D blood levels and investigated their relationship with development of asthma phenotypes in early childhood. The findings were validated in VDAART and in cellular models.

RESULTS

In COPSAC2010, higher vitamin D blood levels at 1 week postpartum were associated with distinct maternal metabolome perturbations with significant enrichment of the sphingomyelin pathway (P < .01). This vitamin D-related maternal metabolic profile at 1 week postpartum containing 46 metabolites was associated with decreased risk of recurrent wheeze (hazard ratio [HR] = 0.92 [95% CI 0.86-0.98], P = .01) and wheeze exacerbations (HR = 0.90 [95% CI 0.84-0.97], P = .01) at ages 0 to 3 years. The same metabolic profile was similarly associated with decreased risk of asthma/wheeze at ages 0 to 3 in VDAART (odds ratio = 0.92 [95% CI 0.85-0.99], P = .04). Human bronchial epithelial cells treated with high-dose vitamin D3 showed an increased cytoplasmic sphingolipid level (P < .01).

CONCLUSIONS

This exploratory metabolomics study in 2 independent birth cohorts demonstrates that the beneficial effect of higher gestational vitamin D exposure on offspring respiratory health is characterized by specific maternal metabolic alterations during pregnancy, which involves the sphingomyelin pathway.

Limosilactobacillus reuteri 29A Cell-Free Supernatant Antibiofilm and Antagonistic Effects in Murine Model of Vulvovaginal Candidiasis

Vaginal dysbiosis advocates burgeoning of devious human vaginal pathobionts like Candida species that possess multiple virulence properties and metabolic flexibility to cause infections. Inevitably, antifungal resistance may emerge due to their innate nature (e.g., biofilm formation), which assists in their virulence as well as the formation of persister cells after dispersal. In consequence, the phenomenon of biofilm involvement in vulvovaginal candidiasis (VVC) and its recurrence is becoming paramount. Lactic acid bacteria and their derivatives have proven to be hostile to Candida species. Here, we throw more light on the potency of the derivatives, i.e., cell-free supernatant (CFS) produced by an indigenously isolated vaginal Lactobacillus strain, Limosilactobacillus reuteri 29A. In the present study, we investigated the antibiofilm and antagonistic effects of L. reuteri 29A CFS, against biofilms of Candida species and in murine model of vulvovaginal candidiasis. In our in vitro biofilm study, the CFS disrupted and inhibited preformed biofilms of C. albicans and C. glabrata. Scanning electron microscopy displayed the destruction of preformed biofilms and impediment of C. albicans morphogenesis by the CFS. Gas chromatography-mass spectrometry analysis showed multiple key compounds that may act singly or synergistically. In vivo, the CFS showed no collateral damage to uninfected mice; the integrity of infected vaginal tissues was restored by the administration of the CFS as seen from the cytological, histopathological, and electron microscopical analyses. The results of this study document the potential use of CFS as an adjuvant or prophylactic option in addressing vaginal fungal infections.

The vulvar microbiome in lichen sclerosus and high-grade intraepithelial lesions

Background

The role of the vulvar microbiome in the development of (pre)malignant vulvar disease is scarcely investigated. The aim of this exploratory study was to analyze vulvar microbiome composition in lichen sclerosus (LS) and vulvar high-grade squamous intraepithelial lesions (HSIL) compared to healthy controls.

Methods

Women with vulvar lichen sclerosus (n = 10), HSIL (n = 5) and healthy controls (n = 10) were included. Swabs were collected from the vulva, vagina and anal region for microbiome characterization by metagenomic shotgun sequencing. Both lesional and non-lesional sites were examined. Biophysical assessments included trans-epidermal water loss for evaluation of the vulvar skin barrier function and vulvar and vaginal pH measurements.

Results

Healthy vulvar skin resembled vaginal, anal and skin-like microbiome composition, including the genera Prevotella, Lactobacillus, Gardnerella, Staphylococcus, Cutibacterium, and Corynebacterium. Significant differences were observed in diversity between vulvar skin of healthy controls and LS patients. Compared to the healthy vulvar skin, vulvar microbiome composition of both LS and vulvar HSIL patients was characterized by significantly higher proportions of, respectively, Papillomaviridae (p = 0.045) and Alphapapillomavirus (p = 0.002). In contrast, the Prevotella genus (p = 0.031) and Bacteroidales orders (p = 0.038) were significantly less abundant in LS, as was the Actinobacteria class (p = 0.040) in vulvar HSIL. While bacteria and viruses were most abundant, fungal and archaeal taxa were scarcely observed. Trans-epidermal water loss was higher in vulvar HSIL compared to healthy vulvar skin (p = 0.043).

Conclusion

This study is the first to examine the vulvar microbiome through metagenomic shotgun sequencing in LS and HSIL patients. Diseased vulvar skin presents a distinct signature compared to healthy vulvar skin with respect to bacterial and viral fractions of the microbiome. Key findings include the presence of papillomaviruses in LS as well as in vulvar HSIL, although LS is generally considered an HPV-independent risk factor for vulvar dysplasia. This exploratory study provides clues to the etiology of vulvar premalignancies and may act as a steppingstone for expanding the knowledge on potential drivers of disease progression.

Investigation of Luliconazole-Loaded Mucoadhesive Electrospun Nanofibers for Anticandidal Activity in the Management of Vaginal Candidiasis

In this study, we fabricated and evaluated luliconazole-loaded electrospun nanofibers for anticandidal activity in the management of vaginal candidiasis. Polycaprolactone (PCL)/gelatin nanofibers were designed by the electrospinning technique, and the Box-Behnken design (BBD) was adopted for optimization to get tailored fibers. The luliconazole (LCZ) drug was mixed into different concentrations (2.5, 5, 7.5, and 10%) of tea tree oil (TT oil) and loaded into the PCL/gelatin nanofibrous mats. The effective anticandidal potential of nanofiber samples were analyzed by the disk-diffusion method. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), XRD analysis, and in silico study were performed. The entrapment efficiency, swelling degree, mechanical strength, contact angle, mucoadhesion, drug release, and permeation study were assessed. The average diameter of the PCL/gelatin-optimized nanofiber was 153 nm. SEM reflected that the fabricated nanofibers were uniform and bead-free. FTIR and DSC analyzed the interaction and physical entrapment of the drug in the polymeric fibers. The entrapment efficiency of the drug-loaded nanofiber was found to be 89.2 ± 0.8%. Maximum swelling percentages at 4 h were 40.8, 18.9, and 14.0% and contact angles were 46.5°, 62.95°, and 65.78° for the blank, TT oil-loaded, and drug-loaded nanofiber, respectively, which indicated the hydrophilic nature of the fibers. The drug-loaded nanofiber had a high tensile strength with satisfactory mucoadhesive property that led to its adhesion to the vaginal mucosa with no tear. The drug-loaded nanofiber had a cumulative drug release of 67.7 ± 3.4% in 48 h, and the 12.8 ± 0.53 mm of zone of inhibition (ZOI) in 48 h illustrated an effective anticandidal activity. The TT oil-loaded nanofiber also exhibited a small ZOI of 4.3 ± 0.30 mm, indicating a synergistic effect to the antifungal activity of the drug-loaded nanofiber. LCZ-loaded nanofibers can emerge as a novel approach for vaginal drug delivery in the treatment of candida infection. Thus, this pharmaceutical investigation can help in formulating preclinical and clinical models.

Development and stability of intimate soap formulations using Sapindus saponaria L. extract as a natural surfactant

The use of synthetic surfactants reflects the high demand in the hygiene and cleaning sector for products with low-cost and good-effectiveness. These ingredients are the main components of intimate soap formulations. Sapindus saponaria L. is a plant rich in saponins, with the potential to be used as a natural surfactant due to its amphiphilic character and its foam-forming properties. Therefore, this study aimed to develop intimate soap formulations using S. saponaria extract as a natural surfactant and analyze its stability and surfactant characteristics. Preliminary and accelerated stability parameters, rheological characteristics, surface tension, foaming power, foam stability and emulsification potential were evaluated. The formulations were stable at a pH suitable for the intimate region (4.0 to 4.5), the presence of S. saponaria extract provided greater reduction of surface tension, better foaming and foam stability and greater emulsification power, desirable characteristics for an intimate liquid soap. These results demonstrate that the incorporation of S. saponaria extract into liquid soap formulations is an excellent option as a natural surfactant to reduce the use of synthetic anionic surfactants such as SLES.

Vaginal colonization of women after oral administration of Lactobacillus crispatus strain NTCVAG04 from the human microbiota

BACKGROUND

The genomic approach has deeply changed the microbiology perspective, mainly concerning the microbioma identification. In this regard, some microbes colonize the healthy vagina. Vaginitis is a common gynecological ailment and includes bacterial vaginosis (BV), usually caused by local dysbiosis, such as a microbiota imbalance. Lactobacilli are the most prevalent bacteria colonizing the healthy vagina, so guaranteeing local eubiosis. In particular, vaginal colonization by L. crispatus is associated with low susceptibility to BV. Therefore, probiotics, such as life bacteria providing health advantages, are a current strategy in the prevention or treatment of vaginitis, including BV. However, there is a low level of evidence that probiotics after ingestion could really colonize the vagina. In particular, no study evidenced that L. crispatus after ingestion can colonize vagina. Therefore, the current study explored the capacity of Biovaginil® (NTC, Milan, Italy) dietary supplement containing Lactobacillus crispatus NTCVAG04 and vitamin A to colonize the gut and vagina in women with a history of vaginitis/vaginosis.

METHODS

Twenty fertile females (mean age 34.0 years) were enrolled in the study. Rectal and vaginal swabs were collected at baseline and after the first and second cycle of Biovaginil®. Each cycle lasted 14 days within two consecutive menstrual periods.

RESULTS

Seven women were excluded from the analysis because the samples were technically not evaluable. One woman dropped out because of mild adverse event. At the end of the study, nine women (75%) had positive rectal swab for L. crispatus NTCVAG04, and 8 of them also had positive vaginal swab.

CONCLUSIONS

The current study provided the first evidence that L. crispatus NTCVAG04, administered by two Biovaginil® courses, colonized both the gut and vagina. Moreover, the L. crispatus NTCVAG04 strain could be considered the archetype of a new class of oral probiotics that actively colonize the vagina, and that could be called "colpobiotics."

Menstrual Tampons Are Reliable and Acceptable Tools to Self-Collect Vaginal Microbiome Samples

Many women report embarrassment as the cause for their avoidance of routine gynaecological screening appointments. Methods of self-collection of bio samples would perhaps encourage women to participate in routine screening programs. The vaginal microbiome plays a key role in women's health and reproductive function. Microbial disturbances can result in the loss of lactobacillus dominance, also known as dysbiosis, associated with an increased risk of contracting sexually transmitted infections (STIs), pregnancy complications and infertility. Our primary aim was to determine if vaginal microbiome screening results are comparable between two methods for self-collected sample acquisition: tampons and lower vaginal swabs (LVSs). Secondary aims included the assessment of the effect of pre-analytic storage on the data (to streamline processing), the prevalence of dysbiosis and the acceptability of the tampons to the participants. Statistical analysis revealed no significant difference in the microbiome data, from tampons versus LVSs or fresh versus frozen samples. The prevalence of dysbiosis in this population of healthy volunteers was 42.9%. The questionnaire data revealed that 52.4% of volunteers use tampons every period, and the majority of volunteers rated the tampons as 5 on a 1-5 Likert scale regarding their perceived comfort using tampons. All (100%) of volunteers were happy to provide a tampon as a sample for testing. The findings from this study show that tampons and LVSs were comparable when analysing the vaginal microbiome, with potential superiority of the tampon with regard to patient acceptability. Self-collection of vaginal secretions for gynaecological screening using tampons warrants further research as this could change the screening landscape, ensuring wider participation and increasing efficacy.

Impact of exposure to air pollution on cervicovaginal microbial communities

PURPOSE

Vaginal microbial communities can be dominated by anaerobic (community state type IV, CST IV) or Lactobacillus (other CSTs) species. CST IV is a risk factor for spontaneous preterm birth (sPTB) and is more common among Black than White populations. In the US, average air pollution exposures are higher among Black compared to White people and exert systemic health effects. We sought to (1) quantify associations of air pollution, specifically particulate matter <2.5 μm in diameter (PM2.5), with CST IV and (2) explore the extent to which racial disparities in PM2.5 exposure might explain racial differences in the prevalence of CST IV.

DESIGN

Methods: We performed a secondary analysis of 566 participants of the Motherhood & Microbiome study. PM2.5 exposures were derived from a machine learning model integrating NASA satellite and EPA ground monitor data. Previously, cervicovaginal swabs from 15 to 20 weeks' gestation were analyzed using 16 S rRNA sequencing and hierarchical clustering assigned CSTs. Multivariable logistic regression models calculated adjusted odds ratios of CST IV (vs. other CSTs) per interquartile range (IQR) increment of PM2.5. Race-stratified and mediation analyses were performed.

RESULTS

Higher PM2.5 exposure was associated with CST IV (aOR 1.39, 95% CI 1.02-1.91). Further adjustment for race/ethnicity attenuated the association (aOR 1.34, 95% CI: 0.97-1.83). Black participants (vs. White) had higher median PM2.5 exposure (10.6 vs. 9.6 μg/m3, P < 0.001) and higher prevalence of CST IV (47% vs. 11%, P < 0.001). Mediation analysis revealed that higher PM2.5 exposure may explain 3.9% (P = 0.038) and 3.3% (P = 0.15) of the Black-White disparity in CST IV in unadjusted and adjusted models, respectively.

CONCLUSION

PM2.5 was associated with CST IV, a risk factor for sPTB. Additionally, PM2.5 exposure may partially explain racial differences in the prevalence of CST IV. Further research is warranted to discover how environmental exposures affect microbial composition and perpetuate racial health disparities.

Advanced Technologies for Studying Microbiome-Female Reproductive Tract Interactions: Organoids, Organoids-on-a-Chip, and Beyond

The female reproductive tract (FRT) is home to diverse microbial communities that play a pivotal role in reproductive health and disorders such as infertility, endometriosis, and cervical cancer. To understand the complex host-microbiota interactions within the FRT, models that authentically replicate the FRT's environment, including the interplay between the microbiota, mucus layer, immune system, and hormonal cycle, are key. Recent strides in organoid and microfluidic technologies are propelling research in this domain, offering insights into FRT-microbiota interactions and potential therapeutic avenues. This review delves into the current state of FRT organoid models and microbe integration techniques, evaluating their merits and challenges for specific research objectives. Emphasis is placed on innovative approaches and applications, including integrating organoids with microfluidics, and using patient-derived biobanks, as this offers potential for deeper mechanistic insights and personalized therapeutic strategies. Modeling various FRT properties in organoids is explored, from encompassing age-related epithelial features, oxygen levels, and hormonal effects to mucus layers, immune responses, and microbial interactions, highlighting their potential to transform reproductive health research and predict possible outcomes.

Emerging role of the host microbiome in neuropsychiatric disorders: overview and future directions

The human body harbors a diverse ecosystem of microorganisms, including bacteria, viruses, and fungi, collectively known as the microbiota. Current research is increasingly focusing on the potential association between the microbiota and various neuropsychiatric disorders. The microbiota resides in various parts of the body, such as the oral cavity, nasal passages, lungs, gut, skin, bladder, and vagina. The gut microbiota in the gastrointestinal tract has received particular attention due to its high abundance and its potential role in psychiatric and neurodegenerative disorders. However, the microbiota presents in other body tissues, though less abundant, also plays crucial role in immune system and human homeostasis, thus influencing the development and progression of neuropsychiatric disorders. For example, oral microbiota imbalance and associated periodontitis might increase the risk for neuropsychiatric disorders. Additionally, studies using the postmortem brain samples have detected the widespread presence of oral bacteria in the brains of patients with Alzheimer's disease. This article provides an overview of the emerging role of the host microbiota in neuropsychiatric disorders and discusses future directions, such as underlying biological mechanisms, reliable biomarkers associated with the host microbiota, and microbiota-targeted interventions, for research in this field.

New Possibilities for Hormonal Vaginal Treatment in Menopausal Women

Hormonal vaginal therapy is an effective treatment option for women who experience vaginal symptoms related to hormonal changes. Estrogen and prasterone are widely used as vaginal treatments, particularly for urogenital atrophy. These symptoms may include vaginal dryness, itching, burning, and pain during sexual intercourse, all of which can significantly affect a woman's quality of life. Previous studies have indicated that such treatment improves tissue elasticity, moisturizes the vagina, and can have a substantial impact on urine incontinence and vaginal microflora and decreases dyspareunia. Hormonal therapy is also useful and commonly used before vaginal surgical treatment. Prasterone is quite a new option for vaginal therapy in Poland and is mainly recommended for dyspareunia in menopausal women. The study related to prasterone therapy emphasizes its effectiveness and safety, making it advantageous to explore its beneficial impact. This paperwork aims to summarize the mechanism of action as well as the effects of both drugs and their beneficial action during vaginal treatment.

Alterations in vaginal microbiota in uterine fibroids patients with ultrasound-guided high-intensity focused ultrasound ablation

Introduction

Vaginal microbiota dysbiosis is closely related to diseases of the vagina and uterus. Uterine fibroids (UF) are the most common benign neoplasms of the uterus, and increased diversity in vaginal microbial of UF patients. High-intensity focused ultrasound (HIFU) is effective invasive treatment for fibroids in women who are not good surgical candidates. Whether HIFU of uterine fibroids will cause the change in vaginal microbiota has not been reported. We aimed to investigate the vaginal microbiota of UF patients with/without HIFU treatment using 16S rRNA gene sequencing.

Methods

Vaginal secretions were collected from 77 UF patients (pre-operative and post-operative) and were used for comparative composition, diversity, and richness analyses of microbial communities.

Results

The microbial α-diversity was significantly lower in the vaginal of UF patients with HIFU treatment. The relative abundance of some pathogenic bacteria of UF patients with HIFU treatment were significantly decreased in the bacterial phylum and genus level. Proteobacteria were found to be significantly upregulated as a biomarker in the HIFU treatment group in our study.

Conclusion

These findings might confirm the effectiveness of HIFU treatment from the point of view of microbiota.

Comparing Vaginal and Endometrial Microbiota Using Culturomics: Proof of Concept

It is generally accepted that microorganisms can colonize a non-pathological endometrium. However, in a clinical setting, endometrial samples are always collected by passing through the vaginal-cervical route. As such, the vaginal and cervical microbiomes can easily cross-contaminate endometrial samples, resulting in a biased representation of the endometrial microbiome. This makes it difficult to demonstrate that the endometrial microbiome is not merely a reflection of contamination originating from sampling. Therefore, we investigated to what extent the endometrial microbiome corresponds to that of the vagina, applying culturomics on paired vaginal and endometrial samples. Culturomics could give novel insights into the microbiome of the female genital tract, as it overcomes sequencing-related bias. Ten subfertile women undergoing diagnostic hysteroscopy and endometrial biopsy were included. An additional vaginal swab was taken from each participant right before hysteroscopy. Both endometrial biopsies and vaginal swabs were analyzed using our previously described WASPLab-assisted culturomics protocol. In total, 101 bacterial and two fungal species were identified among these 10 patients. Fifty-six species were found in endometrial biopsies and 90 were found in vaginal swabs. On average, 28 % of species were found in both the endometrial biopsy and vaginal swab of a given patient. Of the 56 species found in the endometrial biopsies, 13 were not found in the vaginal swabs. Of the 90 species found in vaginal swabs, 47 were not found in the endometrium. Our culturomics-based approach sheds a different light on the current understanding of the endometrial microbiome. The data suggest the potential existence of a unique endometrial microbiome that is not merely a presentation of cross-contamination derived from sampling. However, we cannot exclude cross-contamination completely. In addition, we observe that the microbiome of the vagina is richer in species than that of the endometrium, which contradicts the current sequence-based literature.

Alterations of Vaginal Microbiota and Chlamydia trachomatis as Crucial Co-Causative Factors in Cervical Cancer Genesis Procured by HPV

Chlamydia trachomatis and human papillomavirus (HPV) are the most common pathogens found in sexually transmitted infections (STIs), and both are known to increase the risk of cervical cancer (CC) and infertility. HPV is extremely common worldwide, and scientists use it to distinguish between low-risk and high-risk genotypes. In addition, HPV transmission can occur via simple contact in the genital area. From 50 to 80% of sexually active individuals become infected with both C. trachomatis and HPV viruses during their lifetime, and up to 50% become infected with an HPV oncogenic genotype. The natural history of this coinfection is strongly conditioned by the balance between the host microbiome and immune condition and the infecting agent. Though the infection often regresses, it tends to persist throughout adult life asymptomatically and silently. The partnership between HPV and C. trachomatis is basically due to their similarities: common transmission routes, reciprocal advantages, and the same risk factors. C. trachomatis is a Gram-negative bacteria, similar to HPV, and an intracellular bacterium, which shows a unique biphasic development that helps the latter continue its steady progression into the host throughout the entire life. Indeed, depending on the individual’s immune condition, the C. trachomatis infection tends to migrate toward the upper genital tract and spread to the uterus, and the fallopian tubes open up a pathway to HPV invasion. In addition, most HPV and C. trachomatis infections related to the female genital tract are facilitated by the decay of the first line of defense in the vaginal environment, which is constituted by a healthy vaginal microbiome that is characterized by a net equilibrium of all its components. Thus, the aim of this paper was to highlight the complexity and fragility of the vaginal microenvironment and accentuate the fundamental role of all elements and systems involved, including the Lactobacillus strains (Lactobacillus gasseri, Lactobacillus jensenii, Lactobacillus crispatus) and the immune–endocrine system, in preserving it from oncogenic mutation. Therefore, age, diet, and genetic predisposition together with an unspecific, persistent low-grade inflammatory state were found to be implicated in a high frequency and severity grade of disease, potentially resulting in pre-cancerous and cancerous cervical lesions.

Commensal Lactobacilli Metabolically Contribute to Cervical Epithelial Homeostasis in a Species-Specific Manner

In reproductive-age women, the vaginal microbiome is typically dominated by one or a few Lactobacillus species, including Lactobacillus crispatus, Lactobacillus iners, Lactobacillus paragasseri, Lactobacillus mulieris, and Lactobaccillus crispatus, has been associated with optimal cervicovaginal health; however, much is still unknown about how other lactobacilli metabolically contribute to cervicovaginal health. We hypothesized that metabolites of each Lactobacillus species differ and uniquely contribute to health and homeostasis. To address this hypothesis, we utilized a human three-dimensional (3D) cervical epithelial cell model in conjunction with genomics analyses and untargeted metabolomics to determine the metabolic contributions of less-studied vaginal lactobacilli-L. iners, L. paragasseri, and L. mulieris. Our study validated that vaginal lactobacilli exhibit a close phylogenetic relationship. Genomic findings from publicly available strains and those used in our study indicated that L. iners is metabolically distinct from other species of lactobacilli, likely due to a reduced genome size. Lactobacilli and mock controls were distinguishable based on global metabolic profiles. We identified 95 significantly altered metabolites (P < 0.05) between individual lactobacilli and mock controls. Metabolites related to amino acid metabolism were shared among the lactobacilli. N-Acetylated amino acids with potential antimicrobial properties were significantly elevated in a species-specific manner. L. paragasseri and L. iners shared aromatic, but not carbohydrate-derived, lactic acid metabolites with potential antimicrobial properties that may contribute to homeostasis of the cervicovaginal environment. Additionally, L. iners uniquely altered lipid metabolism, which may be a sign of adaptation to the cervicovaginal niche. Overall, these findings further elucidate the metabolic contributions of three key vaginal Lactobacillus species in gynecological health. IMPORTANCE Lactobacillus species contribute to cervicovaginal health by their production of lactic acid and other antimicrobial compounds. Yet, much is still unknown regarding the metabolic potential of lesser-studied but common vaginal lactobacilli. Here, we used untargeted metabolomics coupled with our 3D cervical epithelial cell model to identify metabolic differences among vaginal Lactobacillus species (Lactobacillus iners, Lactobacillus paragasseri, and Lactobacillus mulieris) and how those differences related to maintaining homeostasis of the cervical epithelium. Human 3D cell models are essential tools for studying host-bacteria interactions and reducing confounding factors inherent in clinical studies. Therefore, these unique models allowed us to decipher the putative lactobacilli mechanisms that contribute to their roles in health or disease. Metabolic analyses revealed distinct profiles of each Lactobacillus species but also shared metabolic contributions associated with antimicrobial activity: amino acid metabolism, N-acetylated amino acids, and aromatic lactic acids. These patterns provided validation of metabolites associated with health in clinical studies and provided novel targets, including immunomodulatory and antimicrobial metabolites, for postbiotic therapies.

Scoping review of cytolytic vaginosis literature

BACKGROUND

Cytolytic vaginosis (CV) is a little-known, controversial condition that is typically not considered for women presenting with vulvovaginitis symptoms. Objective: The objective of this scoping review was to identify and compile the global evidence on CV.

METHODS

A medical librarian searched Prospero, Wiley Cochrane Library, Ovid Embase, Ovid Medline, EBSCO CINAHL, ProQuest Dissertations and Theses Global, and Scopus, from inception to April 4, 2019 and updated to October 17, 2021. Studies were eligible if they discussed CV. Two independent reviewers conducted study selection and data extraction.

RESULTS

Sixty-four studies were identified, with 67% of studies (n = 43) published since 2007. Studies were from around the world, including the United States (28%, n = 18), Brazil (11%, n = 7), Portugal (11%, n = 7), and China (11%, n = 7). Fifty percent of studies (n = 32) were reviews; the remainder were observational; and of these, 78% (n = 25) were cross-sectional. The most frequent topics included: diagnosis (19%, n = 12), prevalence (17%, n = 11), and overview of CV (50%, n = 32). Evidence for prevalence in symptomatic women (median prevalence of 5%, interquartile range 3%-8%) was based only on 16% of studies (n = 10) with minimal evidence on prevalence in asymptomatic women and across different geographic regions. Microbiological findings, including abundant lactobacilli and fragmented epithelial cells, were found useful to distinguish between CV and vulvovaginal candidiasis, and Lactobacillus crispatus was noted to dominate the vaginal flora in women with CV. Most studies used subjective criteria to diagnose CV as the condition lacks gold-standard microscopic criteria. The suggested primary treatment (baking soda irrigations) was largely based on expert opinion, and there was minimal evidence on associations between CV and other conditions.

CONCLUSION

Knowledge gaps currently exist in all realms of CV research. Additional research is needed to confirm the validity of CV and ensure that women are diagnosed and treated effectively.

Joint effects of individual socioeconomic status and residential neighborhood context on vaginal microbiome composition

Introduction

The vaginal microbiome is a dynamic ecosystem that is important for women's health. Its composition has been associated with risk for menopausal symptoms, sexually transmitted infections, gynecologic cancer, and preterm birth. Conventional risk factors for a vaginal microbiome linked with these adverse health outcomes include sexual behaviors, hygiene practices, individual social factors, and stress levels. However, there has been limited research on socio-contextual determinants, and whether neighborhood context modifies the association with individual socioeconomic factors.

Methods

Socioeconomically diverse pregnant African American women in Atlanta, Georgia (n = 439) provided residential addresses and first trimester vaginal swab samples, which underwent sequencing, taxonomic classification, and assignment into mutually exclusive CST (community state types) via hierarchical clustering. Linear probability models were used to estimate prevalence differences (PD) for the associations of neighborhood factors with vaginal microbiome CST and to evaluate for additive interaction with maternal level of education, health insurance type, and recruitment hospital.

Results

Factors such as higher (vs. lower) maternal education, private (vs. public) insurance, and private (vs. public) hospital were associated with higher prevalence of Lactobacillus-dominant vaginal microbiome CSTs typically associated with better health outcomes. When considering the joint effects of these individual socioeconomic status and residential neighborhood factors on vaginal microbiome CST, most combinations showed a greater than additive effect among the doubly exposed; however, in the case of local income homogeneity and local racial homogeneity, there was evidence of a crossover effect between those with less-advantaged individual socioeconomic status and those with more-advantaged individual socioeconomic status. Compared to women at the public hospital who lived in economically diverse neighborhoods, women at the private hospital who lived in economically diverse neighborhoods had a 21.9% higher prevalence of Lactobacillus-dominant CSTs, while women at the private hospital who lived in less economically diverse neighborhoods (the doubly exposed) had only an 11.7% higher prevalence of Lactobacillus-dominant CSTs, showing a crossover effect (interaction term p-value = 0.004).

Discussion

In this study, aspects of residential neighborhood context were experienced differently by women on the basis of their individual resources, and the joint effects of these exposures on vaginal microbiome CST showed a departure from simple additivity for some factors.

The Implication of Mechanistic Approaches and the Role of the Microbiome in Polycystic Ovary Syndrome (PCOS): A Review

As a complex endocrine and metabolic condition, polycystic ovarian syndrome (PCOS) affects women's reproductive health. These common symptoms include hirsutism, hyperandrogenism, ovulatory dysfunction, irregular menstruation, and infertility. No one knows what causes it or how to stop it yet. Alterations in gut microbiota composition and disruptions in secondary bile acid production appear to play a causative role in developing PCOS. PCOS pathophysiology and phenotypes are tightly related to both enteric and vaginal bacteria. Patients with PCOS exhibit changed microbiome compositions and decreased microbial diversity. Intestinal microorganisms also alter PCOS patient phenotypes by upregulating or downregulating hormone release, gut-brain mediators, and metabolite synthesis. The human body's gut microbiota, also known as the "second genome," can interact with the environment to improve metabolic and immunological function. Inflammation is connected to PCOS and may be caused by dysbiosis in the gut microbiome. This review sheds light on the recently discovered connections between gut microbiota and insulin resistance (IR) and the potential mechanisms of PCOS. This study also describes metabolomic studies to obtain a clear view of PCOS and ways to tackle it.

Altered Gut Microbial Profile Accompanied by Abnormal Fatty Acid Metabolism Activity Exacerbates Endometrial Cancer Progression

Endometrial cancer (EC) is the most prevalent gynecological malignancy, with a higher risk in obese woman, indicating the possibility of gut microbiota involvement in EC progression. However, no direct evidence of a relationship between EC and gut microbiota in humans has been discovered. Here, we performed 16S rRNA sequencing to explore the relationship between dysbiosis of gut microbiota and cancer development in different types of EC patients. The results clearly show the differential profiles of gut microbiota between EC patients and normal participants as well as the association between gut microbiota and EC progression. Targeted metabolomics of plasma revealed an increased level of C16:1 and C20:2, which was positively associated with the abundance of Ruminococcus sp. N15.MGS-57. The higher richness of Ruminococcus sp. N15.MGS-57 in EC subjects not only was positively associated with blood C16:1 and C20:2 but also was negatively correlated with betalain and indole alkaloid biosynthesis. Furthermore, the combined marker panel of gut bacteria, blood metabolites, and clinical indices could distinguish the EC patients under lean and overweight conditions from normal subjects with high accuracy in both discovery and validation sets. In addition, the alteration of tumor microenvironment metabolism of EC was characterized by imaging mass microscopy. Spatial visualization of fatty acids showed that C16:1 and C18:1 obviously accumulate in tumor tissue, and C16:1 may promote EC cell invasion and metastasis through mTOR signaling. The aberrant fecal microbiome, more specifically, Ruminococcus sp. N15.MGS-57 and spatially distributed C16:1 in EC tissues, can be used as a biomarker of clinical features and outcomes and provide a new therapeutic target for clinical treatment. IMPORTANCE A growing number of studies have shown the connection between gut microbiota, obesity, and cancer. However, to our knowledge, the association between gut microbiota and endometrial cancer progression in humans has not been studied. We recruited EC and control individuals as research participants and further subgrouped subjects by body mass index to examine the association between gut microbiota, metabolites, and clinical indices. The higher richness of Ruminococcus sp. N15.MGS-57 in EC subjects was not only positively associated with blood C16:1 but also negatively correlated with betalain and indole alkaloid biosynthesis. Spatial visualization of fatty acids by imaging mass microscopy showed that C16:1 obviously accumulates in tumor tissue, and C16:1 may promote the EC cell invasion and metastasis through mTOR signaling. The aberrant fecal microbiome, more specifically, Ruminococcus sp. N15.MGS-57 and spatially distributed C16:1, can be used as a biomarker of clinical features and outcomes and provide a new therapeutic target for clinical treatment.

Gut and genital tract microbiomes: Dysbiosis and link to gynecological disorders

Every year, millions of women are affected by genital tract disorders, such as bacterial vaginosis (BV), endometrial cancer, polycystic ovary syndrome (PCOS), endometriosis, and uterine fibroids (UFs). These disorders pose a significant economic burden on healthcare systems and have serious implications for health and fertility outcomes. This review explores the relationships between gut, vaginal, and uterine dysbiosis and the pathogenesis of various diseases of the female genital tract. In recent years, reproductive health clinicians and scientists have focused on the microbiome to investigate its role in the pathogenesis and prevention of such diseases. Recent studies of the gut, vaginal, and uterine microbiomes have identified patterns in bacterial composition and changes across individuals' lives associated with specific healthy and diseased states, particularly regarding the effects of the estrogen-gut microbiome axis on estrogen-driven disorders (such as endometrial cancer, endometriosis, and UFs) and disorders associated with estrogen deficiency (such as PCOS). Furthermore, this review discusses the contribution of vitamin D deficiency to gut dysbiosis and altered estrogen metabolism as well as how these changes play key roles in the pathogenesis of UFs. More research on the microbiome influences on reproductive health and fertility is vital.

A systematic assessment of stress insomnia as the high-risk factor for cervical cancer and interplay of cervicovaginal microbiome

Cervical cancer is a dreaded form of cancer in women, the fourth most common cancer, with around 0.3 million females suffering from this disease worldwide. Over the past several decades, global researches have focused on the mitigation of cervical lesions and cancers and have explored the impact of physiological and psychological stress and insomnia on cervical pathogenesis. Furthermore, disruption of the cervicovaginal microbiome profiles is identified as an added high-risk factor for the occurrence of cervical cancer. The physiological regulation of stress has an underlying mechanism controlled via hypothalamic pituitary adrenal (HPA) and sympatho-adrenal medullary (SAM) axes. Disruptions in these axes have been identified as the factors responsible for maintaining the homeostasis balance. Recent studies on microbiomes have offered novel ways to combat cervical cancer and cervix infection by exploring the interplay of the cervicovaginal microbiome. Moreover, the integration of various immune cells and microbiome diversity is known to act as an effective strategy to decipher the cervix biological activity. Cytokine profiling and the related immune competence, and physiological stress and insomnia impart to the regulatory networks underlying the mechanism which may be helpful in designing mitigation strategies. This review addressed the current progress in the research on cervical cancer, HPV infection, immune cell interaction, and physiological stress and insomnia with the cervicovaginal microbiome to decipher the disease occurrence and therapeutic management.

Lactobacilli extracellular vesicles: potential postbiotics to support the vaginal microbiota homeostasis

Background

Lactobacillus species dominate the vaginal microflora performing a first-line defense against vaginal infections. Extracellular vesicles (EVs) released by lactobacilli are considered mediators of their beneficial effects affecting cellular communication, homeostasis, microbial balance, and host immune system pathways. Up to now, very little is known about the role played by Lactobacillus EVs in the vaginal microenvironment, and mechanisms of action remain poorly understood.

Results

Here, we hypothesized that EVs can mediate lactobacilli beneficial effects to the host by modulating the vaginal microbiota colonization. We recovered and characterized EVs produced by two vaginal strains, namely Lactobacillus crispatus BC5 and Lactobacillus gasseri BC12. EVs were isolated by ultracentrifugation and physically characterized by Nanoparticle Tracking Analysis (NTA) and Dynamic Light Scattering (DLS). EVs protein and nucleic acids (DNA and RNA) content was also evaluated. We explored the role of EVs on bacterial adhesion and colonization, using a cervical cell line (HeLa) as an in vitro model. Specifically, we evaluated the effect of EVs on the adhesion of both vaginal beneficial lactobacilli and opportunistic pathogens (i.e., Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, and Enterococcus faecalis). We demonstrated that EVs from L. crispatus BC5 and L. gasseri BC12 significantly enhanced the cellular adhesion of all tested lactobacilli, reaching the maximum stimulation effect on strains belonging to L. crispatus species (335% and 269% of average adhesion, respectively). At the same time, EVs reduced the adhesion of all tested pathogens, being EVs from L. gasseri BC12 the most efficient.

Conclusions

Our observations suggest for the first time that EVs released by symbiotic Lactobacillus strains favor healthy vaginal homeostasis by supporting the colonization of beneficial species and preventing pathogens attachment. This study reinforces the concept of EVs as valid postbiotics and opens the perspective of developing postbiotics from vaginal strains to maintain microbiota homeostasis and promote women’s health.

Vaginal microbiome: considerations for reproductive health

The microbial communities are an indispensable part of the human defense system and coexist with humans as symbionts, contributing to the metabolic functions and immune defense against pathogens. An ecologically stable vaginal microbiota is dominated by Lactobacillus species, which plays an important role in the prevention of genital infections by controlling the vaginal pH, reducing glycogen to lactic acid, and stimulating bacteriocins and hydrogen peroxide. In contrast, an abnormal vaginal microbial composition is associated with an increased risk of bacterial vaginosis, trichomoniasis, sexually transmitted diseases, preterm labor and other birth defects. This microbial diversity is affected by race, ethnicity, pregnancy, hormonal changes, sexual activities, hygiene practices and other conditions. In the present review, we discuss the changes in the microbial community of the vaginal region at different stages of a female's life cycle and its influence on her reproductive health and pathological conditions.

Changes in the Vaginal Microbiota of Women With Secondary Localized Provoked Vulvodynia

OBJECTIVE

The etiology of localized provoked vulvodynia (LPV) remains unknown, but observations suggest the involvement of the vaginal microbiota. We examined the vaginal microbiota of women with LPV and healthy controls, upon after a low-oxalate diet (LOD).

MATERIALS AND METHODS

A total of 9 women diagnosed with secondary LPV and 21 healthy controls were recruited from the Galilee Medical Center in Israel and subjected to prospective evaluations of their vaginal microbiota. Total DNA was extracted from vaginal discharge samples provided before and after following LOD for 3 weeks and was then subjected to 16S sequencing. Data obtained were then used to evaluate α and β diversity, identify differentially abundant bacterial taxa in LPV, and determine their impact on the metabolism.

RESULTS

These evaluations revealed decreased diversity in the vaginal microbiota of women with LPV and identified the Ochrobactrum genus and Pseudomonadaceae family as indicators for LPV. In addition, we identified 23 differentially expressed bacterial metabolic pathways between the LPV and control samples and revealed that LOD could induce changes in the β diversity of LPV vaginal microbiomes, which was further supported by some degree of pain reduction in patients.

CONCLUSIONS

Localized provoked vulvodynia and LOD were associated with shifts in the vaginal microbiota. However, the impact of these changes on the development of LPV requires additional studies with a larger cohort.

Characterization of Early Inflammatory Events Leading to Provoked Vulvodynia Development in Rats

Background

Provoked vulvodynia (PV) is the main cause of vulvar pain and dyspareunia. The etiology of PV has not yet been elucidated. However, PV is associated with a history of recurrent inflammation, and its often accompanied by increases in the numbers of mast cells (MCs) and sensory hyperinnervation in the vulva. Therefore, this study aimed to examine the role of MCs and the early inflammatory events in the development of chronic vulvar pain in a rat model of PV.

Methods

Mechanical and thermal vulvar sensitivity was measured for 5 months following zymosan vulvar challenges. Vulvar changes in glutamate and nerve growth factor (NGF) were analyzed using ELISA. Immunofluorescence (IF) staining of the vulvar section after 20, 81, and 160 days of the zymosan challenge were performed to test MCs accumulation, hyperinnervation, and expression of pain channels (transient receptor potential vanilloid/ankyrin-1-TRPV1 & TRPA1) in vulvar neurons. Changes in the development of vulvar pain were evaluated following the administration of the MCs stabilizer ketotifen fumarate (KF) during zymosan vulvar challenges.

Results

Zymosan-challenged rats developed significant mechanical and thermal vulvar sensitivity that persisted for over 160 days after the zymosan challenge. During inflammation, increased local concentrations of NGF and glutamate and a robust increase in MCs degranulation were observed in zymosan-challenged rats. In addition, zymosan-challenged rats displayed sensory hyperinnervation and an increase in the expression of TRPV1 and TRPA1. Treatment with KF attenuated the upregulated level of NGF during inflammation, modulated the neuronal modifications, reduced MCs accumulation, and enhanced mechanical hypersensitivity after repeated inflammation challenges.

Conclusion

The present findings suggest that vulvar hypersensitivity is mediated by MCs accumulation, nerve growth, and neuromodulation of TRPV1 and TRPA1. Hence, KF treatment during the critical period of inflammation contributes to preventing chronic vulvar pain development.

Role of Vaginal Mucosa, Host Immunity and Microbiota in Vulvovaginal Candidiasis

Vulvovaginal candidiasis (VVC) is a prevalent gynaecological disease characterised by vaginal wall inflammation that is caused by Candida species. VVC impacts almost three-quarters of all women throughout their reproductive years. As the vaginal mucosa is the first point of contact with microbes, vaginal epithelial cells are the first line of defence against opportunistic Candida infection by providing a physical barrier and mounting immunological responses. The mechanisms of defence against this infection are displayed through the rapid shedding of epithelial cells, the presence of pattern recognition receptors, and the release of inflammatory cytokines. The bacterial microbiota within the mucosal layer presents another form of defence mechanism within the vagina through acidic pH regulation, the release of antifungal peptides and physiological control against dysbiosis. The significant role of the microbiota in maintaining vaginal health promotes its application as one of the potential treatment modalities against VVC with the hope of alleviating the burden of VVC, especially the recurrent disease. This review discusses and summarises current progress in understanding the role of vaginal mucosa and host immunity upon infection, together with the function of vaginal microbiota in VVC.

Inhibitory effect of Lactobacillus gasseri CCFM1201 on Gardnerella vaginalis in mice with bacterial vaginosis

Gardnerella vaginalis is the core pathogen of bacterial vaginosis (BV), the most common vaginal infection in women. G. vaginalis exerts pathogenicity through various factors, such as biofilm formation and the local host immune response stimulation. Therefore, this study aimed to evaluate the inhibitory effect of Lactobacillus gasseri CCFM1201 on G. vaginalis using experimental BV models. We evaluated L. gasseri in vitro to inhibit pathogen biofilm formation and adhesion capacity in HeLa cells using crystal violet staining. Further in vivo studies were conducted to assess the inhibitory effects of L. gasseri CCFM1201 on BV induced by G. vaginalis. L. gasseri exhibited strain-specific adhesion and inhibition of pathogen biofilm formation in vitro. L. gasseri CCFM1201 significantly reduced G. vaginalis in mice (p < 0.05), inhibited sialidase activity, modulated tumor necrosis factor-α and interleukin-1β expression, and reduced myeloperoxidase activity (p < 0.05). Histopathological examination indicated that L. gasseri CCFM1201 improved inflammatory cell infiltration of vaginal tissue and restored its structure. Vaginal epithelial cell exfoliation, the main clinical feature of BV, was significantly improved by L. gasseri CCFM1201 intervention (p < 0.05). Thus, L. gasseri CCFM1201 is a potential candidate for treating G. vaginalis-induced vaginal diseases.

Healthy Vaginal Microbiota and Influence of Probiotics Across the Female Life Span

Vaginal microbiota plays a central role in women’s health and reproduction. Vaginal microbiota is dynamic and shaped by hormonal shifts in each stage of a woman’s life from pre-puberty to postmenopause. Current research has mainly focused on vaginal bacterial and fungal members of the community and emphasized their role in disease. However, the impact of balanced vaginal microbiota on health and its interaction with the host is yet poorly understood. High abundance of vaginal lactobacilli is most strongly associated with health, but the concept of health may vary as vaginal dysbiosis may be asymptomatic. Furthermore, there is a lot of variation between ethnic groups in terms of dominating vaginal bacteria. Probiotic lactobacilli could be a safe and natural means to balance and maintain healthy vaginal microbiota. Research evidence is accumulating on their role in supporting women’s health throughout life. This review describes the current literature on vaginal microbiota, the major factors affecting its composition, and how the communities change in different life stages. Furthermore, we focused on reviewing available literature on probiotics and their impact on vaginal microbiota and health.

Towards a deeper understanding of the vaginal microbiota

The human vaginal microbiota is a critical determinant of vaginal health. These communities live in close association with the vaginal epithelium and rely on host tissues for resources. Although often dominated by lactobacilli, the vaginal microbiota is also frequently composed of a collection of facultative and obligate anaerobes. The prevalence of these communities with a paucity of Lactobacillus species varies among women, and epidemiological studies have associated them with an increased risk of adverse health outcomes. The mechanisms that drive these associations have yet to be described in detail, with few studies establishing causative relationships. Here, we review our current understanding of the vaginal microbiota and its connection with host health. We centre our discussion around the biology of the vaginal microbiota when Lactobacillus species are dominant versus when they are not, including host factors that are implicated in shaping these microbial communities and the resulting adverse health outcomes. We discuss current approaches to modulate the vaginal microbiota, including probiotics and vaginal microbiome transplants, and argue that new model systems of the cervicovaginal environment that incorporate the vaginal microbiota are needed to progress from association to mechanism and this will prove invaluable for future research.

Human microbial dysbiosis as driver of gynecological malignancies

Gynecological cancers that affect female reproductive tract, remain at the top of the global cancer burden list with high relapse rate and mortality. Notwithstanding development of several novel therapeutic interventions including poly-ADP-ribose polymerase inhibitors, this family of malignancies remain deadly. The human microbiome project demonstrated that dysbiosis of health resident microflora is associated with several pathologies including malignancies of the female reproductive tract and detailed characterization of species variation and host-microbe interaction could provide clues for identification of early diagnostic biomarker, preventive and therapeutic interventions. Emerging evidence suggests that several microbial signatures are significantly associated with gynecological cancers. An increased population of Proteobacteria and Firmicutes followed by significantly reduced Lactobacilli are associated with lethal epithelial ovarian cancer. Similarly, a constant association of elevated level of Atopobium vaginae, Porphyromonas somerae, Micrococci and Gardnerella vaginalis are observed in endometrial and cervical cancers. Moreover, human papilloma virus infection significantly augments colonization of pathogenic microbes including Sneathia sanguinegens, Anaerococcus tetradius, and Peptostreptococcus anaerobius and drives carcinoma of the cervix. Interestingly, microbial dysbiosis in female reproductive tract modulates expression of several microbial and immune-responsive genes such as TLR-4, TLR-5, TLR-6 and NOD-1. Therefore, stringent investigation into the microbial dysbiosis and its underlying mechanism could provide valuable cues for identification of early diagnostic biomarker, preventive and therapeutic interventions against rogue gynecological malignancies.

Evaluation of inhibitory and probiotic properties of lactic acid bacteria isolated from vaginal microflora

Lactic acid bacteria (LABs) are known to secrete species-specific secondary metabolites that could be utilized as novel therapeutics against multi-drug resistant pathogens. This study aimed to investigate the antagonistic and probiotic properties of LABs isolated from the vaginal ecosystem of healthy women and to assess the stability of their antagonistic metabolites. Among 43 strains isolated from healthy women, eight LAB strains exhibited detectable BLISs (bacteriocin-like substances) producing ability against E. faecalis (JH-86), S. aureus (JH-68), Streptococcus sp. (JH-80), and E. coli (JH-101), with zone of inhibition (ZI) ranging from 9.00 to 20.33 mm and minimum inhibitory concentrations (MICs) from 62.5 to 500 μL/mL, respectively. The partially purified compounds extracted from cell free supernatant (CFS) displayed an increase in antagonistic activity based on ZI, 9.67-30.17 mm and MICs, 3.91-15.63 mg/mL, respectively. In a time-kill study, both crude and partially purified compounds of Limosilactobacillus reuteri (MT180537), Pediococcus pentosaceus (MT176555), Limosilactobacillus pontis (MW362838), and Levilactobacillus brevis (MW362790) exhibited significant bactericidal action against E. faecalis (MW051601), the most frequent etiological agent of aerobic vaginitis (AV). The active secondary metabolites from L. reuteri (MT180537), P. pentosaceus (MT176555), and L. pontis (MW362838) were protein in nature and remained stable under different physicochemical conditions. Regarding probiotic properties, the strains presented probiotic characteristics, i.e., good acid, bile salt tolerance, aggregation properties, and biofilm formation. The strains were susceptible to most of the commonly used antibiotics and had no hemolytic activity. In conclusion, antagonistic compounds or BLIS produced by L. reuteri (MT180537) could be investigated further for preparation of ointments to treat AV.

The Microbiome as a Key Regulator of Female Genital Tract Barrier Function

The microbiome, the collection of microbial species at a site or compartment, has been an underappreciated realm of human health up until the last decade. Mounting evidence suggests the microbiome has a critical role in regulating the female genital tract (FGT) mucosa's function as a barrier against sexually transmitted infections (STIs) and pathogens. In this review, we provide the most recent experimental systems and studies for analyzing the interplay between the microbiome and host cells and soluble factors with an influence on barrier function. Key components, such as microbial diversity, soluble factors secreted by host and microbe, as well as host immune system, all contribute to both the physical and immunologic aspects of the FGT mucosal barrier. Current gaps in what is known about the effects of the microbiome on FGT mucosal barrier function are compared and contrasted with the literature of the gut and respiratory mucosa. This review article presents evidence supporting that the vaginal microbiome, directly and indirectly, contributes to how well the FGT protects against infection.

Community Structure and Ecological Network's Changes of Vaginal Microbiome in Women Right After Delivery

OBJECTIVES

Vaginal microbiota is not only an important source of bacterial colonization for neonates, but also plays a crucial role in maternal and neonatal health. This study aimed to investigate the vaginal microbial community structure right after delivery and its impact on the neonatal oral microbiome.

METHODS

In this study, 27 women were recruited from Bao'an Maternal and Child Health Hospital. Bacterial compositions of vaginal samples before and right after delivery and neonatal oral samples right after birth were investigated using 16S rRNA sequencing of V3-V4 hyperregions.

RESULTS

Vaginal microbiome before delivery was dominated by the genus Lactobacillus. After delivery, the vaginal microbial community was altered, with significantly decreased proportion of Lactobacillus, increased alpha-diversity, and a more diverse ecological network. A large number subjects dominated by Lactobacillus species before delivery shifted to CST (community state type) IV after delivery. In addition, similar changes were observed in the neonatal oral microbiome, and its community profile was closer to vaginal samples after delivery than before delivery with principal coordinates analysis and microbial source tracking analysis.

CONCLUSION

The vaginal microbiome was altered right after delivery and impacted the colonization of the neonatal oral microbiome in China. Further, it is vital to understand the longitudinal influence on maternal and neonatal health of vaginal microbiome community changes after delivery.

The Vaginal Microbiome: IV. The Role of Vaginal Microbiome in Reproduction and in Gynecologic Cancers

OBJECTIVE

This series of articles, titled The Vaginal Microbiome (VMB), written on behalf of the International Society for the Study of Vulvovaginal Disease, aims to summarize the recent findings and understanding of the vaginal bacterial microbiota, mainly regarding areas relevant to clinicians specializing in vulvovaginal disorders.

MATERIALS AND METHODS

A search of PubMed database was performed, using the search terms "vaginal microbiome" with "reproduction," "infertility," "fertility," "miscarriages," "pregnancy" "cervical cancer," "endometrial cancer," and "ovarian cancer." Full article texts were reviewed. Reference lists were screened for additional articles.

RESULTS

The fourth article of this series focuses on 2 distinct areas: the role of VMB in various aspects of human reproduction and, in sharp contrast, the association between the VMB and gynecologic malignancies. Several of the negative pregnancy outcomes have been associated with an altered VMB. Dysbiosis is remarkably linked with poor pregnancy outcomes from preconception to delivery. The associations between the microbiome and gynecologic cancers are described.

CONCLUSIONS

The development of the microbiome research, enabled by molecular-based techniques, has dramatically increased the detection of microorganisms and the understanding of bacterial communities that are relevant to maternal-fetal medicine in health and disease, as well as in gynecological malignancies. Proving causation in cancer is difficult because of the complex interactive nature of potential causative factors. Certain elements of the microbiota have been shown to provoke inflammatory reactions, whereas others produce anti-inflammatory reactions; this balance might be impaired with a change in microbial variety.

Characteristics of the vaginal microbiome in women with premature ovarian insufficiency

PURPOSE

To investigate the relationship between vaginal microbial community structure and premature ovarian insufficiency (POI).

METHODS

Twenty-eight women with POI and 12 healthy women were recruited at Shenzhen Maternity and Child Healthcare Hospital between August and September 2020. Blood samples were collected for glucose tests and detection of sex hormone levels and vaginal secretions were collected for microbial group determination. Vaginal microbial community profiles were analysed by 16S rRNA gene sequencing using the Illumina MiSeq system (Illumina Inc., San Diego, CA, USA).

RESULTS

Compared to the controls, the serum levels of follicle-stimulating hormone, luteinizing hormone, testosterone, and the follicle-stimulating hormone/luteinizing hormone ratio, significantly increased, and oestradiol and anti-Müllerian hormone levels significantly decreased in women with POI. Higher weighted UniFrac values were observed in women with POI than in healthy women. Bacteria in the genera Lactobacillus, Brevundimonas, and Odoribacter were more abundant in the microbiomes of healthy women, while the quantity of bacteria in the genus Streptococcus was significantly increased in the microbiomes of women with POI. Moreover, these differences in microbes in women with POI were closely related to follicle-stimulating hormone, luteinizing hormone, oestradiol, and anti-Müllerian hormone levels and to the follicle-stimulating hormone/luteinizing hormone ratio.

CONCLUSIONS

Women with POI had altered vaginal microbial profiles compared to healthy controls. The alterations in their microbiomes were associated with serum hormone levels. These results will improve our understanding of the vaginal microbial community structure in women with POI.

TRIAL REGISTRATION

CHICTR, ChiCTR2000029576 . Registered 3 August 2020 - Retrospectively registered, https://www.chictr.org.cn/showproj.aspx?proj=48844 .

Changes in the Microbiome of Vaginal Fluid after Menopause in Korean Women

Various microorganisms reside in the human vagina; the vaginal microbiome is closely linked to both vaginal and general health, and for this reason, microbiome studies of the vagina are an area of research. In this study, we analyzed the vaginal microbiome of women before and after menopause to further increase our understanding of the vaginal microbiome and its contribution to general health. We did a 16s rRNA gene-based metagenomic analysis on the vaginal fluids of 11 premenopausal and 19 postmenopausal women in Korea. We confirmed that the taxonomic composition was significantly different between the two groups. In postmenopausal women, species richness was significantly decreased, but species diversity was significantly increased. In particular, among the taxonomic components corresponding to all taxon ranks of the vaginal microbiome, a reduction in Lactobacillus taxa after menopause contributed the most to the difference between the two groups. In addition, we confirmed through metabolic analysis that the lactic-acid concentration was also decreased in the vaginal fluid of women after menopause. Our findings on the correlation between menopause and the microbiome could help diagnose menopause and enhance the prevention and treatment diseases related to menopause.

Does probiotics work for bacterial vaginosis and vulvovaginal candidiasis

The different Lactobacillus strains of probiotics have been applied to the treatment and prevention of bacterial vaginosis and vulvovaginal candidiasis. The experimental data demonstrated that it works well via reducing the number of harmful bacteria, maintaining the acidic microenvironment, inhibiting the immune response, and so on, to restore the vaginal microecology. However, the clinical data indicated that it is not sufficient to support the use of probiotics in the intervention of vulvovaginal candidiasis rather than bacterial vaginosis. Hunting for novel probiotic strains and uncovering the precise mechanism of probiotics, especially with the new concept gut-vagina axis, to maintain the homeostasis of vaginal microbiota should be a great challenge in the future.