Vaginal Microbiota and Cytokine Microenvironment in HPV Clearance/Persistence in Women Surgically Treated for Cervical Intraepithelial Neoplasia: An Observational Prospective Study

Impact of postsurgical vaginal microbiome on high-risk HPV infection and recurrence risk in patients with cervical cancer and intraepithelial neoplasia: A retrospective study

Purpose

This study aimed to determine the effect of postsurgical vaginal microbiome (VM) on high-risk human papillomavirus (hrHPV) infection and the risk of disease recurrence in patients surgically treated for cervical cancer (CC) or intraepithelial neoplasia (CIN).

Methods

207 women who underwent surgical treatment for CC or CIN at the Department of Gynecologic Oncology of the First Affiliated Hospital of University of Science and Technology of China from November 2016 to October 2023 were included. The patients' clinical data, including age, surgical modality, and diagnosis at time of index surgery, were collected retrospectively and analyzed. Associations between postsurgical VM indices, hrHPV infection, cervical cytology, and recurrence were also evaluated.

Results

Patient age, surgical modality (whether complete excision of the cervix was performed), and diagnosis at time of index surgery (cervical dysplasia vs. cervical carcinoma) showed no significant association with postsurgical hrHPV infection, cervical cytology, or disease recurrence. However, postsurgical VM imbalance was significantly associated with hrHPV infection status (OR = 4.640, 95 % CI = 2.085-10.460, P < 0.001), abnormal cervical cytology (OR = 3.994, 95 % CI = 1.154-13.826, P = 0.020), and disease recurrence (OR = 3.789, 95 % CI = 1.091-13.154, P = 0.026). Among the specific VM indices, a vaginal pH above 4.5 (OR = 4.570, 95 % CI = 1.640-12.690, P = 0.002), a lactobacilli proportion below 50 % (OR = 3.938, 95 % CI = 1.299-11.934, P = 0.010), and the presence of aerobic vaginitis (AV, OR = 2.425, 95 % CI = 0.996-5.901, P = 0.046) were risk factors for postsurgical recurrence.

Conclusion

Postsurgical VM imbalance, especially abnormal indices, such as a pH above 4.5, a lactobacilli proportion below 50 %, and the presence of AV, was associated with an increased risk of postsurgical recurrence in patients who underwent surgical treatment for CIN and CC. Monitoring and potentially intervening in the VM may improve the prognosis of these patients.

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.

Genetic and epigenetic alterations in DNA repair genes and treatment outcome of chemoradiotherapy in cervical cancer

Cervical cancer (CaCx) is the deadliest malignancy among women which is caused by human papillomavirus (HPV) and anthro-demographical/clinicopathological factors. HPV oncoproteins E6 and E7 target p53 and RB (retinoblastoma) protein degradation, Ataxia telangiectasia mutated (ATM), ATM-RAD3-related (ATR) inactivation and subsequent impairment of non-homologous end joining (NHEJ), homologous recombination, and base excision repair pathways. There is also an accumulation of genetic and epigenetic alterations in Tumor Growth Suppressors (TGS), oncogenes, and DNA repair genes leading to increased genome instability and CaCx development. These alterations might be responsible for differential clinical response to Cisplatin-based chemoradiotherapy (CRT) in patients. This review explores HPV-mediated DNA damage as a risk factor in CaCx development, the mechanistic role of genetic and epigenetic alterations in DNA repair genes and their association with CRT and outcome, It also explores new possibilities for the development of genetic and epigenetic-based biomarkers for diagnostic, prognostic, and molecular therapeutic interventions.

A Decrease in Lactobacilli in the Vaginal Microbiota Is Independently Associated With HPV Persistence in Women With High-Risk HPV Infection

Background Vaginal dysbiosis, an imbalance between species, can initiate some local changes in immune and metabolic signaling causing chronic inflammation. The mechanism of the clearance or progression of the HPV infection has not been uncovered yet. We hypothesized that vaginal dysbiosis may contribute to the persistence of the cervical HPV infection. Therefore we aimed to determine the association of lactobacillus dominancy index with cervical HR-HPV persistence. Methods A total of 100 women who were followed up because of high-risk HPV infection were defined as the target study group. The patients were evaluated in two groups; HPV positive (group with HPV persistence, n=43) and HPV negative (group with HPV clearance, n=57). Cervicovaginal swab samples and blood samples were evaluated for Nugent score, lactobacillus dominance, and white blood cell count. Statistical tests were performed by the IBM Statistical Product and Service Solutions (version 22, IBM SPSS Statistics for Windows, Armonk, NY) program. The continuous variables were presented using the mean±standard deviation (SD), and the categorical variables were presented as the number of cases and their percentage. A p value less than 0.05 (<0.05) was set as statistically significant. Results HPV persistence was observed in 43 (43%) patients. Univariate analysis revealed that age, menopausal status, and lactobacillus reduction were associated with HPV persistence (p<0.05). The median value of the Nugent score was similar among groups. After logistic regression analysis, lactobacillus reduction continued to be associated with HPV persistence, independent of age and menopause (OR: 2.668, 96% CI: 1.069-6.662, p<0.05) Conclusions A decrease in lactobacilli in the cervicovaginal microbiota is associated with the persistence of HPV, regardless of age and menopausal status in this study.

High risk HPV-positive women cervicovaginal microbial profiles in a Greek cohort: a retrospective analysis of the GRECOSELF study

Increasing evidence supports a role for the vaginal microbiome (VM) in the severity of HPV infection and its potential link to cervical intraepithelial neoplasia. However, a lot remains unclear regarding the precise role of certain bacteria in the context of HPV positivity and persistence of infection. Here, using next generation sequencing (NGS), we comprehensively profiled the VM in a series of 877 women who tested positive for at least one high risk HPV (hrHPV) type with the COBAS® 4,800 assay, after self-collection of a cervico-vaginal sample. Starting from gDNA, we PCR amplified the V3-V4 region of the bacterial 16S rRNA gene and applied a paired-end NGS protocol (Illumina). We report significant differences in the abundance of certain bacteria compared among different HPV-types, more particularly concerning species assigned to Lacticaseibacillus, Megasphaera and Sneathia genera. Especially for Lacticaseibacillus, we observed significant depletion in the case of HPV16, HPV18 versus hrHPVother. Overall, our results suggest that the presence or absence of specific cervicovaginal microbial genera may be linked to the observed severity in hrHPV infection, particularly in the case of HPV16, 18 types.

Vaginal microecology and its role in human papillomavirus infection and human papillomavirus associated cervical lesions

The vaginal microecology comprises the vaginal microbiome, immune microenvironment, vaginal anatomy, and the cervicovaginal fluid, which is rich in metabolites, enzymes, and cytokines. Investigating its role in the female reproductive system holds paramount significance. The advent of next-generation sequencing enabled a more profound investigation into the structure of the vaginal microbial community in relation to the female reproductive system. Human papillomavirus infection is prevalent among women of reproductive age, and persistent oncogenic HPV infection is widely recognized as a factor associated with cervical cancer. Extensive previous research has demonstrated that dysbiosis of vaginal microbiota characterized by a reduction in Lactobacillus species, heightens susceptivity to HPV infection, consequently contributing to persistent HPV infection and the progression of cervical lesion. Likewise, HPV infection can exacerbate dysbiosis. This review aims to provide a comprehensive summary of current literatures and to elucidate potential mechanisms underlying the interaction between vaginal microecology and HPV infection, with the intention of offering valuable insights for future clinical interventions.

Bacterial Species from Vaginal Microbiota Differently Affect the Production of the E6 and E7 Oncoproteins and of p53 and p-Rb Oncosuppressors in HPV16-Infected Cells

Vaginal dysbiosis is characterized by a decrease in the relative abundance of Lactobacillus species in favor of other species. This condition facilitates infections by sexually transmitted pathogens including high risk (HR)-human papilloma viruses (HPVs) involved in the development of cervical cancer. Some vaginal dysbiosis bacteria contribute to the neoplastic progression by inducing chronic inflammation and directly activating molecular pathways involved in carcinogenesis. In this study, SiHa cells, an HPV-16-transformed epithelial cell line, were exposed to different representative vaginal microbial communities. The expression of the HPV oncogenes E6 and E7 and the production of relative oncoproteins was evaluated. The results showed that Lactobacillus crispatus and Lactobacillus gasseri modulated the basal expression of the E6 and E7 genes of SiHa cells and the production of the E6 and E7 oncoproteins. Vaginal dysbiosis bacteria had contrasting effects on E6/E7 gene expression and protein production. The expression of the E6 and E7 genes and the production of the relative oncoproteins was increased by strains of Gardnerella vaginalis and, to a lesser extent, by Megasphaera micronuciformis. In contrast, Prevotella bivia decreased the expression of oncogenes and the production of the E7 protein. A decreased amount of p53 and pRb was found in the cultures of SiHa cells with M. micronuciformis, and accordingly, in the same cultures, a higher percentage of cells progressed to the S-phase of the cell cycle compared to the untreated or Lactobacillus-stimulated cultures. These data confirm that L. crispatus represents the most protective component of the vaginal microbiota against neoplastic progression of HR-HPV infected cells, while M. micronuciformis and, to a lesser extent, G. vaginalis may directly interfere in the oncogenic process, inducing or maintaining the production of viral oncoproteins.

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.

Role of the human vaginal microbiota in the regulation of inflammation and sexually transmitted infection acquisition: Contribution of the non-human primate model to a better understanding?

The human vaginal microbiota has a central role in the regulation of the female reproductive tract (FRT) inflammation. Indeed, on one hand an optimal environment leading to a protection against sexually transmitted infections (STI) is associated with a high proportion of Lactobacillus spp. (eubiosis). On the other hand, a more diverse microbiota with a high amount of non-Lactobacillus spp. (dysbiosis) is linked to a higher local inflammation and an increased STI susceptibility. The composition of the vaginal microbiota is influenced by numerous factors that may lead to a dysbiotic environment. In this review, we first discuss how the vaginal microbiota composition affects the local inflammation with a focus on the cytokine profiles, the immune cell recruitment/phenotype and a large part devoted on the interactions between the vaginal microbiota and the neutrophils. Secondly, we analyze the interplay between STI and the vaginal microbiota and describe several mechanisms of action of the vaginal microbiota. Finally, the input of the NHP model in research focusing on the FRT health including vaginal microbiota or STI acquisition/control and treatment is discussed.

The effect of cold-knife conization on pregnancy outcomes in patients with cervical lesions

OBJECTIVE

To analyze the pregnancy outcomes of patients with cervical lesions treated by cold-knife conization (CKC).

METHODS

Clinical data of healthy pregnant women and pregnant women who underwent CKC in Dalian Women and Children's Medical Group from March 2010 to December 2019 were retrospectively analyzed. These patients were divided into a CKC group and a control group according to inclusion and exclusion criteria. Statistical methods were used to compare pregnancy and delivery outcomes between the two groups.

RESULTS

There were 400 patients in CKC group and control group, with 200 patients in each. There was no significant difference in the mode of delivery, abortion, ectopic pregnancy, in-hospital perinatal management, and cervical cerclage between the CKC group and the control group (P>0.05). The rates of preterm delivery, premature rupture of membranes, cesarean section, and neonatal admission in the CKC group were higher than those in the control group (P<0.05). In the CKC group, the incidence of premature rupture of membranes within six months postoperatively was higher than that after six months (P<0.05). The incidences of preterm delivery and premature rupture of membranes were not completely consistent in different conization ranges (P<0.05).

CONCLUSION

CKC increases the incidence of preterm delivery, premature rupture of membranes, and neonatal adverse outcomes. Conization height can predict the occurrence of preterm delivery. Delaying pregnancy after surgery can reduce the incidence of adverse outcomes during the perinatal period.

Evaluation of cytokine profile in cervicovaginal lavage specimens of women having asymptomatic reproductive tract infections

Reproductive tract infections (RTIs) such as vaginal candidiasis and bacterial vaginosis (BV) are common among sexually active women and can be both symptomatic or asymptomatic. The microbiota of the reproductive tract triggers immune response at the cervicovaginal interface resulting in secretion of cytokines during the course of these RTIs. The objective of this study was to evaluate the cytokine profile in cervicovaginal lavage of women having asymptomatic vaginal infections. Measurement of vaginal cytokines was done for various interleukins including IL-1β, IL-6, IL-8, IL-10, IL-12/IL23p40, IL-17A, tumour necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) by ProcartaPlex™ Multiplex Immunoassay. Women having vaginal Candida infection had increased concentration of IL-1β (p=.01), IL-6 (p=.007), IL-8 (p=.327), IL-12/IL23p40 (p=.049) and IFN-γ (p=.125). The results of our study suggest that evaluation of these cytokines could be explored as an additional measure to determine host inflammatory response in women having asymptomatic vaginal candidiasis.Impact StatementWhat is already known on this subject? Studies assessing the vaginal cytokine profile to assess the vaginal milieu in various cohorts such as post-menopausal women, pregnant women, women with history of preterm birth, CIN and scheduled IVF cycle are being undertaken. Variable cytokine response has been reported in literature in women with symptomatic bacterial vaginosis and Candida infection. However, much less is known about vaginal cytokine profile in asymptomatic infection.What do the results of this study add? The results of the study show increased concentration of the pro-inflammatory cytokines IL-1β, IL-6 IL-8, IL-12/IL23p40 and interferon gamma (IFN-γ) in women having asymptomatic Candida, vaginal leucocytosis and raised vaginal pH.What are the implications of these findings for clinical practice and/or further research? Evaluation of vaginal cytokine profile (IL-1β, IL-6 IL-8, IL-1β, IL-12/IL23p40 and IFN-γ) could be explored as an additional measure to determine inflammation in asymptomatic women. Vaginal cytokines (IL-1β, IL-6 IL-8, IL-1β, IL-12/IL23p40 and IFN-γ) could be used further for development of a point of care test.

Cervicovaginal microbiota isolated from healthy women exhibit probiotic properties and antimicrobial activity against pathogens isolated from cervical cancer patients

Abnormal cervicovaginal microbiota play an important role in HPV persistence and progression to cervical cancer. The present study aimed at isolating and identifying potential probiotics from vaginal swabs of healthy women and evaluating their activity against vaginal pathogens isolated from cervical cancer patients. Based on probiotic, acid-bile tolerance and antimicrobial properties, 13 lactic acid bacteria (LAB) from the healthy group were identified by MALDI TOF MS (Matrix Assisted Laser Desorption and Ionisation, Time Of Flight Mass Spectrometry). Among these, four strains, Lactobacillus gasseri P36Mops, Limosilactobacillus fermentum P37Mws, Lactobacillus delbrueckii P31Mcs and Enterococcus faecium P26Mcm, exhibited significant antimicrobial activity against 8 vaginal pathogens (Staphylococcus haemolyticus P41Tcs, Escherichia coli P30Tcs, E. coli P79Bcm, Enterococus faecalis P29Mops, E. faecalis P50Tws, E. faecalis P68Tcb, S. haemolyticus P48Bcb and S. haemolyticus P58Bcb) isolated from precancerous and cervical cancer patients. 16S rRNA sequencing of four potential probiotics revealed congruency with the MALDI-TOF MS identification and phylogenetic analysis showed genetic relationship with previously reported LAB strains. The selected LAB showed strain specific hydrophobicity (35.88-56.70%), auto-aggregation (35.26-61.39%) and antibiotic susceptibility. Interestingly, L. gasseri P36Mops was resistant to five standard antibiotics routinely used against urogenital or vaginal infections. LCMS (Liquid Chromatography Mass Spectrometry) analyses of the CFS (cell-free supernatant) of the four potential probiotics revealed the presence of metabolites such as N-(1-deoxy-1-fructosyl)valine, hygroline, acetoxy-2-hydroxy-16-heptadecen-4-one, avocadyne 4-acetate, avocadyne 2-acetate, taraxinic acid glucosyl ester, 6-hydroxypentadecanedioic acid, with reported antimicrobial activity. The overall data suggest the bio-therapeutic potential of the identified vaginal probiotics against cervical cancer-associated pathogens.

Vaginal microbiota associated with oncogenic HPV in a cohort of HPV-vaccinated women living with HIV

Background

Women living with HIV (WLWH) experience higher rates of human papillomavirus (HPV) infection and cervical cancer than women without HIV. Changes in the vaginal microbiome have been implicated in HPV-related disease processes such as persistence of high-risk HPV infection but this has not been well defined in a population living with HIV.

Methods

Four hundred and 20 girls and WLWH, age ≥9, across 14 clinical sites in Canada were enrolled to receive three doses of quadrivalent HPV vaccine for assessment of vaccine immunogenicity. Blood, cervical cytology, and cervico-vaginal swabs were collected. Cervico-vaginal samples were tested for HPV DNA and underwent microbiota sequencing.

Results

Principal component analysis (PCA) and hierarchical clustering generated community state types (CSTs). Relationships between taxa and CSTs with HPV infection were examined using mixed-effects logistic regressions, Poisson regressions, or generalized linear mixed-effects models, as appropriate. Three hundred and fifty-six cervico-vaginal microbiota samples from 172 women were sequenced. Human papillomavirus DNA was detected in 211 (59%) samples; 110 (31%) contained oncogenic HPV. Sixty-five samples (18%) were taken concurrently with incident oncogenic HPV infection and 56 (16%) were collected from women with concurrent persistent oncogenic HPV infection.

Conclusions

No significant associations between taxa, CST, or microbial diversity and HPV-related outcomes were found. However, we observed weak associations between a dysbiotic microbiome and specific species, including Gardnerella, Porphyromonas, and Prevotella species, with incident HPV infection.

Host and Microbiome Interplay Shapes the Vaginal Microenvironment

The female reproductive tract harbors a unique microbiome, especially the vagina. The human vaginal microbiome exhibits a low diversity and is dominated by Lactobacillus species, compared to the microbiome of other organs. The host and vaginal microbiome mutually coexist in the vaginal microenvironment. Host cells provide Lactobacillus glycogen as an energy source, and Lactobacillus produce lactic acid, which lowers vaginal pH thereby preventing growth of other bacteria. Bacterial vaginosis can modulate host immune systems, and is frequently associated with various aspects of disease, including sexually transmitted infection, gynecologic cancer, and poor pregnancy outcomes. Because of this, numerous studies focused on the impact of the vaginal microbiome on women`s health and disease. Furthermore, numerous epidemiologic studies also have demonstrated various host factors regulate the vaginal microbiome. The female reproductive tract undergoes constant fluctuations due to hormonal cycle, pregnancy, and other extrinsic factors. Depending on these fluctuations, the vaginal microbiome composition can shift temporally and dynamically. In this review, we highlight the current knowledge of how host factors modulate vaginal microbiome composition and how the vaginal microbiome contributes to maintaining homeostasis or inducing pathogenesis. A better understanding of relationship between host and vaginal microbiome could identify novel targets for diagnosis, prognosis, or treatment of microbiome-related diseases.

Vaginal Microbiota Changes Caused by HPV Infection in Chinese Women

Human papillomavirus (HPV) infection is one of the most common sexually transmitted diseases. After studying 602 unvaccinated Chinese women using 16S rRNA to detect cervical-vaginal microecology, we analyzed the relationship between HPV infection and vaginal microecology including 20 HPV types. In Chinese women, L. gasseri–dominated and L. jensenii–dominated clusters were significantly absence. Microbial alpha diversity was significantly higher in HPV-infected and cervical intraepithelial neoplasia (CIN)–diagnosed groups than in healthy control group. Certain bacteria were associated with HPV infection and CIN, including Streptococcus, Prevotella, Chlamydia, Bifidobacterium, Ralstonia, and Aerococcus. With the development of disease, the proportions of community state type III (CST-III) and CST-IV-B gradually increased, whereas the proportions of CST-I and CST-IV-A gradually decreased. In addition, age was an influential factor for HPV infection. With aging, the probability of HPV infection and the proportion of CST-IV-B increase. In conclusion, our study was a large cross-sectional study that evaluated the relationship between vaginal microbiota and HPV infection, and brought essential comparable data.

From Microbiome to Inflammation: The Key Drivers of Cervical Cancer

Cervical cancer is the third leading cause of cancer-related death worldwide. Microbes and hosts form a mutually beneficial symbiosis relationship, and various parts of the host body are microbial habitats. Microbes can trigger inflammation in certain parts of the host body, contributing to cervical cancer development. This article reviews the relationship between cervicovaginal microbes, inflammation and cervical cancer, and discusses the effect of some key cervical microbes on cervical cancer. Finally, probiotic therapy and immunotherapy are summarized.

Bacterial vaginosis and other infections in pregnant women in Senegal

Background

Bacterial vaginosis (BV) is associated with a higher risk of preterm delivery and spontaneous abortion. Yet little data on BV prevalence exist for sub-Saharan countries. The aim of this study was to estimate the prevalence of bacterial vaginosis and associated risk factors among pregnant women in Senegal.

Methods

From October 2013 to December 2018, pregnant women in their third trimester were recruited in two primary health centers (one suburban, one rural) in Senegal. Healthcare workers interviewed women and collected a lower vaginal swab and a blood sample. Vaginal flora were classified into four categories using vaginal smear microscopic examination and Gram’s coloration. In our study, BV was defined as vaginal flora with no Lactobacillus spp. Variables associated with BV were analyzed using STATA® through univariate and multivariate analysis.

Results

A total of 457 women provided a vaginal sample for analysis. Overall, BV prevalence was 18.6% (85/457) [95% CI 15.4–22.6]) and was similar in suburban and rural areas (18.9% versus 18.1%, p = 0.843). Multivariate analysis showed that primigravidity was the only factor independently associated with a lower risk of BV (aOR 0.35 [95% CI 0.17–0.72]).

Conclusions

Our study showed significant BV prevalence among pregnant women in Senegal. Although the literature has underscored the potential consequences of BV for obstetric outcomes, data are scarce on BV prevalence in sub-Saharan African countries. Before authorities consider systematic BV screening for pregnant women, a larger study would be useful in documenting prevalence, risk factors and the impact of BV on pregnancy outcomes.

Characterization of Vaginal Microbiota in Women With Recurrent Spontaneous Abortion That Can Be Modified by Drug Treatment

Objective

The role of vaginal microbiota in recurrent spontaneous abortion (RSA) remains unknown. The purpose of this study was to investigate characteristics of vaginal microbiota and the effects of drug treatment on vaginal microbiota of patients with RSA.

Methods

A case-control study was performed, in which non-pregnant patients who experienced RSA were selected and divided into untreated and drug-treated groups. Drug-treated patients were subdivided into the metformin group, metformin plus aspirin group, and other drugs group. Healthy women who had live births and never experienced spontaneous abortion were enrolled in the control group. Characteristics of vaginal microbiomes of patients with RSA and healthy women and the impact of drug treatment on the microbiome was evaluated via 16S rRNA gene sequencing of the V3-V4 region using the Illumina MiSeq platform.

Results

Women who underwent RSA had lower microbial richness than healthy women. Compared to controls, the relative abundance of seven taxa (Megasphaera, Sneathia sanguinegens, Pseudomonas, Sphingomonas, Rhodococcus, Burkholderia- Caballeronia-Paraburkholderia, and Corynebacterium_1) in the patient's vaginal microbiota changed significantly, which may be closely related to RSA. The composition of the vaginal microbial community in RSA patients was altered by drug treatment. Metformin combined with aspirin treatment significantly increased the relative abundance of vaginal Lactobacillus spp. in patients.

Conclusion

An altered vaginal microbiome composition might be associated with RSA, which could be modified by drug treatment. The effect of metformin combined with aspirin on vaginal Lactobacillus is worthy of attention.

Alterations of Vaginal Microbiota in Women With Infertility and Chlamydia trachomatis Infection

Chlamydia trachomatis (C. trachomatis) is the most common etiological agent of bacterial sexually transmitted infections (STIs) worldwide and causes serious health sequelae such as cervicitis, pelvic inflammatory disease, and even infertility if ascending from the lower to the upper female genital tract. Previous studies have revealed the pivotal role of vaginal microbiota in susceptibility to STIs. However, alterations in the vaginal microbiota in women who are infertile and infected with C. trachomatis remain unknown. This study used metagenomic analysis of sequenced 16S rRNA gene amplicons to examine the vaginal microbial profiles of women with tubal infertility who were C. trachomatis-negative and those who were C. trachomatis-positive pre- and post-antibiotic treatment. Women who were C. trachomatis-negative and deemed healthy were recruited as references of eubiosis and dysbiosis. Women with tubal infertility and C. trachomatis infection presented a unique Lactobacillus iners-dominated vaginal microbiota rather than one dominated by Lactobacillus crispatus and displayed a decrease in Lactobacillus, Bifidobacterium, Enterobacter, Atopobium, and Streptococcus, accompanied by decreased levels of cytokines such as interferon (IFN)-γ and interleukin (IL)-10. This altered vaginal microbiota could be restored with varying degrees after standard treatment for C. trachomatis. This shift could be a predictive vaginal microbiota signature for C. trachomatis infection among females with tubal infertility, while no significant differences in phylum, class, and operational taxonomic unit (OTU) levels were observed between women with tubal infertility who were C. trachomatis-negative and healthy controls. This is the first study to provide data on the association of vaginal microbiota with C. trachomatis infection among women with tubal infertility and highlights unprecedented potential opportunities to predict C. trachomatis infection.

Vaginal Lactobacilli and Vaginal Dysbiosis-Associated Bacteria Differently Affect Cervical Epithelial and Immune Homeostasis and Anti-Viral Defenses

Persistent infection with High Risk-Human Papilloma Viruses (HR-HPVs) is a primary cause of cervical cancer worldwide. Vaginal-dysbiosis-associated bacteria were correlated with the persistence of HR-HPVs infection and with increased cancer risk. We obtained strains of the most represented bacterial species in vaginal microbiota and evaluated their effects on the survival of cervical epithelial cells and immune homeostasis. The contribution of each species to supporting the antiviral response was also studied. Epithelial cell viability was affected by culture supernatants of most vaginal-dysbiosis bacteria, whereas Lactobacillus gasseri or Lactobacillus jensenii resulted in the best stimulus to induce interferon-γ (IFN-γ) production by human mononuclear cells from peripheral blood (PBMCs). Although vaginal-dysbiosis-associated bacteria induced the IFN-γ production, they were also optimal stimuli to interleukin-17 (IL-17) production. A positive correlation between IL-17 and IFN-γ secretion was observed in cultures of PBMCs with all vaginal-dysbiosis-associated bacteria suggesting that the adaptive immune response induced by these strains is not dominated by T_H1 differentiation with reduced availability of IFN-γ, cytokine most effective in supporting virus clearance. Based on these results, we suggest that a vaginal microbiota dominated by lactobacilli, especially by L. gasseri or L. jensenii, may be able to assist immune cells with clearing HPV infection, bypasses the viral escape and restores immune homeostasis.

The interplay between the vaginal microbiome and innate immunity in the focus of predictive, preventive, and personalized medical approach to combat HPV-induced cervical cancer

HPVs representing the most common sexually transmitted disease are a group of carcinogenic viruses with different oncogenic potential. The immune system and the vaginal microbiome represent the modifiable and important risk factors in HPV-induced carcinogenesis. HPV infection significantly increases vaginal microbiome diversity, leading to gradual increases in the abundance of anaerobic bacteria and consequently the severity of cervical dysplasia. Delineation of the exact composition of the vaginal microbiome and immune environment before HPV acquisition, during persistent/progressive infections and after clearance, provides insights into the complex mechanisms of cervical carcinogenesis. It gives hints regarding the prediction of malignant potential. Relative high HPV prevalence in the general population is a challenge for modern and personalized diagnostics and therapeutic guidelines. Identifying the dominant microbial biomarkers of high-grade and low-grade dysplasia could help us to triage the patients with marked chances of lesion regression or progression. Any unnecessary surgical treatment of cervical dysplasia could negatively affect obstetrical outcomes and sexual life. Therefore, understanding the effect and role of microbiome-based therapies is a breaking point in the conservative management of HPV-associated precanceroses. The detailed evaluation of HPV capabilities to evade immune mechanisms from various biofluids (vaginal swabs, cervicovaginal lavage/secretions, or blood) could promote the identification of new immunological targets for novel individualized diagnostics and therapy. Qualitative and quantitative assessment of local immune and microbial environment and associated risk factors constitutes the critical background for preventive, predictive, and personalized medicine that is essential for improving state-of-the-art medical care in patients with cervical precanceroses and cervical cancer. The review article focuses on the influence and potential diagnostic and therapeutic applications of the local innate immune system and the microbial markers in HPV-related cancers in the context of 3P medicine.