Interplay between the temporal dynamics of the vaginal microbiota and human papillomavirus detection

Vaginal flora in HPV infection: a cross‑sectional analysis

OBJECTIVE

The vaginal flora has been reported to be associated with human papillomavirus (HPV) infection. The purpose of this study was to investigate the characteristics of the cervical microbiota in patients with HPV infection and to analyse the changes in the vaginal flora and enzyme profiles in females with HPV infection.

METHODS

We conducted a cross-sectional study involving 206 participants who underwent HPV genotyping, sexually transmitted diseases pathogen testing, cytology examination, and microbiome analysis. Additionally, we collected 115 HPV-negative samples and 48 HPV-positive samples for 16S rRNA amplicon sequencing. The vaginal microbial communities of both groups were analysed for diversity and differences to explore their association with HPV infection.

RESULTS

The abundance of Lactobacillus was found to be reduced, while Gardnerella vaginalis was significantly more prevalent in the HPV + group. In terms of alpha diversity indices, the Shannon index (P = .0036) and Simpson index (P = .02) were higher in the HPV + group compared to the HPV - group, indicating greater community diversity in the HPV + group. Among the 10 sexually transmitted diseases pathogens analysed, Uup3 and Uup6 were significantly associated with HPV infection. Statistically significant differences were observed in Nugent scores and bacterial vaginosis between the two groups (P < .05). In functional analysis, 11 proteins and 13 enzymes were found to be significantly altered in the HPV + group.

CONCLUSION

Our study demonstrates that disruptions in the vaginal flora are associated with HPV infection. Reduced levels of Lactobacillus, increased prevalence of Gardnerella, and abnormal enzyme profiles are closely linked to HPV infection.

Key aspects of papillomavirus infection influence the host cervicovaginal microbiome in a preclinical murine papillomavirus (MmuPV1) infection model

Human papillomaviruses (HPVs) are the most common sexually transmitted infection in the United States and are a major etiological agent of cancers in the anogenital tract and oral cavity. Growing evidence suggests changes in the host microbiome are associated with the natural history and ultimate outcome of HPV infection. We sought to define changes in the host cervicovaginal microbiome during papillomavirus infection, persistence, and pathogenesis using the murine papillomavirus (MmuPV1) cervicovaginal infection model. Cervicovaginal lavages were performed over a time course of MmuPV1 infection in immunocompetent female FVB/N mice and extracted DNA was analyzed by qPCR to track MmuPV1 viral copy number. 16S ribosomal RNA (rRNA) gene sequencing was used to determine the composition and diversity of microbial communities throughout this time course. We also sought to determine whether specific microbial communities exist across the spectrum of MmuPV1-induced neoplastic disease. We, therefore, performed laser-capture microdissection to isolate regions of disease representing all stages of neoplastic disease progression (normal, low- and high-grade dysplasia, and cancer) from female reproductive tract tissue sections from MmuPV1-infected mice and performed 16S rRNA sequencing. Consistent with other studies, we found that the natural murine cervicovaginal microbiome is highly variable across different experiments. Despite these differences in initial microbiome composition between experiments, we observed that MmuPV1 persistence, viral load, and severity of disease influenced the composition of the cervicovaginal microbiome. These studies demonstrate that papillomavirus infection can alter the cervicovaginal microbiome.IMPORTANCEHuman papillomaviruses (HPVs) are the most common sexually transmitted infection in the United States. A subset of HPVs that infect the anogenital tract (cervix, vagina, anus) and oral cavity cause at least 5% of cancers worldwide. Recent evidence indicates that the community of microbial organisms present in the human cervix and vagina, known as the cervicovaginal microbiome, plays a role in HPV-induced cervical cancer. However, the mechanisms underlying this interplay are not well-defined. In this study, we infected the female reproductive tract of mice with a murine papillomavirus (MmuPV1) and found that key aspects of papillomavirus infection and disease influence the host cervicovaginal microbiome. This is the first study to define changes in the host microbiome associated with MmuPV1 infection in a preclinical animal model of HPV-induced cervical cancer. These results pave the way for using MmuPV1 infection models to further investigate the interactions between papillomaviruses and the host microbiome.

Temporal composition of the cervicovaginal microbiome associates with hrHPV infection outcomes in a longitudinal study

BACKGROUND

Persistent infections with high-risk human papillomavirus (hrHPV) can cause cervical squamous intraepithelial lesions (SIL) that may progress to cancer. The cervicovaginal microbiome (CVM) correlates with SIL, but the temporal composition of the CVM after hrHPV infections has not been fully clarified.

METHODS

To determine the association between the CVM composition and infection outcome, we applied high-resolution microbiome profiling using the circular probe-based RNA sequencing technology on a longitudinal cohort of cervical smears obtained from 141 hrHPV DNA-positive women with normal cytology at first visit, of whom 51 were diagnosed by cytology with SIL six months later.

RESULTS

Here we show that women with a microbial community characterized by low diversity and high Lactobacillus crispatus abundance at both visits exhibit low risk to SIL development, while women with a microbial community characterized by high diversity and Lactobacillus depletion at first visit have a higher risk of developing SIL. At the level of individual species, we observed that a high abundance for Gardnerella vaginalis and Atopobium vaginae at both visits associate with SIL outcomes. These species together with Dialister micraerophilus showed a moderate discriminatory power for hrHPV infection progression.

CONCLUSIONS

Our results suggest that the CVM can potentially be used as a biomarker for cervical disease and SIL development after hrHPV infection diagnosis with implications on cervical cancer prevention strategies and treatment of SIL.

The microbial revolution: Unveiling the benefits of vaginal probiotics and prebiotics

Vaginal health is essential to a woman's overall well-being, as abnormalities in vaginal health can lead to a variety of gynaecological disorders, such as urinary tract infections, yeast infections, and bacterial vaginosis. The vaginal microbiome is essential for the prevention of these infections. Disruptions in this microbial ecosystem can significantly impact vaginal health. The concept of utilizing probiotics and prebiotics to stimulate the growth of protective vaginal microbiota has gathered substantial interest in recent years. Probiotics are live micro-organisms that strengthen and restore vaginal microbial balance by lowering pH levels, production of bacteriocins, biofilm disruption, modulation of immune response, and production of hydrogen peroxide (H2O2), consequently combating the development of pathogens. Prebiotics are oligosaccharides that encourage the development of probiotics such as lactobacilli species. Probiotics and prebiotics also have some broader implications for vaginal health, including their role in minimizing the incidence of premature birth, optimizing fertility, managing menopausal symptoms, and preventing vaginal infections. Synbiotics are a combination of probiotics and prebiotics that deliver additional benefits by encouraging the development and activity of beneficial microbes. Furthermore, postbiotics are bioactive compounds derived from probiotic bacteria during fermentation that have immunomodulatory actions and provide an additional layer of protection against vaginal infections. The present study highlights the most prevalent vaginal infections and limitations of existing therapies that influence the vaginal microbiota. The profound consequences of probiotics and prebiotics in women's health, including their role in minimizing the prevalence of vaginal infections and promoting overall vaginal health, as well as advanced therapeutic strategies such as synbiotics and postbiotics, are also discussed. The literature offers significant insights into the mechanism, efficacy, and safety of probiotics and prebiotics to healthcare providers and researchers.

Leveraging existing 16S rRNA gene surveys to decipher microbial signatures and dysbiosis in cervical carcinogenesis

The presence of dysbiotic cervicovaginal microbiota has been observed to be linked to the persistent development of cervical carcinogenesis mediated by the human papillomavirus (HPV). Nevertheless, the characteristics of the cervical microbiome in individuals diagnosed with cervical cancer (CC) are still not well understood. Comprehensive analysis was conducted by re-analyzing the cervical 16S rRNA sequencing datasets of a total of 507 samples from six previously published studies. We observed significant alpha and beta diversity differences in between CC, cervical intraepithelial neoplasia (CIN) and normal controls (NC), but not between HPV and NC in the combined dataset. Meta-analysis revealed that opportunistic pernicious microbes Streptococcus, Fusobacterium, Pseudomonas and Anaerococcus were enriched in CC, while Lactobacillus was depleted compared to NC. Members of Gardnerella, Sneathia, Pseudomonas, and Fannyhessea have significantly increased relative abundance compared to other bacteria in the CIN group. Five newly identified bacterial genera were found to differentiate CC from NC, with an area under the curve (AUC) of 0.8947. Moreover, co-occurrence network analysis showed that the most commonly encountered Lactobacillus was strongly negatively correlated with Prevotella. Overall, our study identified a set of potential biomarkers for CC from samples across different geographic regions. Our meta-analysis provided significant insights into the characteristics of dysbiotic cervicovaginal microbiota undergoing CC, which may lead to the development of noninvasive CC diagnostic tools and therapeutic interventions.

Characteristics of Vaginal Microbiota of Women of Reproductive Age with Infections

The vaginal microbiota can be classified into five major community state types (CSTs) based on the bacterial content. However, the link between different CST subtypes and vaginal infection remains unclear. Here, we analyzed 2017 vaginal microbiota samples from women of a reproductive age with vaginal infections that were published in the last decade. We found that L. iners was the most dominant in 34.8% of the vaginal samples, followed by L. crispatus (21.2%). CST I was common in healthy individuals, whereas CST III and IV were associated with dysbiosis and infection. CST III-B, IV-A, IV-B, and IV-C0 were prevalent in patients with bacterial vaginosis (BV). Based on the relative abundance of bacteria at the (sub)genus level, a random forest classifier was developed to predict vaginal infections with an area under the curve of 0.83. We further identified four modules of co-occurring bacterial taxa: L. crispatus, Gardnerella, Prevotella, and Bacteroides. The functional prediction revealed that nucleotide biosynthesis pathways were upregulated in patients with human papilloma virus, and carbohydrate degradation pathways were downregulated in patients with BV. Overall, our study identified the bacterial signatures of healthy and infected vaginal microbiota, providing unique insights into the clinical diagnosis and health status prediction of women of a reproductive age.

Compositional and functional differences of the vaginal microbiota of women with and without cervical dysplasia

Alterations in the vaginal microbiota, including both species composition and functional pathways, have been associated with HPV infection and progression of dysplasia to cervical cancer. To further explore this, shotgun metagenomic sequencing was used to taxonomically and functionally characterize the vaginal microbiota of women with and without cervical dysplasia. Women with histologically verified dysplasia (n = 177; low grade dysplasia (LSIL) n = 81, high-grade dysplasia (HSIL) n = 94, cancer n = 2) were compared with healthy controls recruited from the cervical screening programme (n = 177). Women with dysplasia had a higher vaginal microbial diversity, and higher abundances of Gardnerella vaginalis, Aerococcus christensenii, Peptoniphilus lacrimalis and Fannyhessea vaginae, while healthy controls had higher relative abundance of Lactobacillus crispatus. Genes involved in e.g. nucleotide biosynthesis and peptidoglycan biosynthesis were more abundant in women with dysplasia. Healthy controls showed higher abundance of genes important for e.g. amino acid biosynthesis, (especially L-lysine) and sugar degradation. These findings suggest that the microbiota may have a role in creating a pro-oncogenic environment in women with dysplasia. Its role and potential interactions with other components in the microenvironment deserve further exploration.

Cervicovaginal microbiota: a promising direction for prevention and treatment in cervical cancer

Cervical cancer is a common malignancy in women, with high incidence rate and mortality. Persistent infection of high-risk human papillomavirus (HPV) is the most important risk factor for cervical cancer and precancerous lesions. Cervicovaginal microbiota (CVM) plays an essential role in the defense of HPV infections and prevention of subsequent lesions. Dominance of Lactobacillus is the key of CVM homeostasis, which can be regulated by host, exogenous and endogenous factors. Dysbiosis of CVM, including altered microbial, metabolic, and immune signatures, can contribute to persist HPV infection, leading to cervical cancer. However, there is no evidence of the causality between CVM and cervical cancer, and the underlying mechanism remains unexplored. Considering the close correlation between CVM dysbiosis and persistent HPV infection, this review will overview CVM, its role in cervical cancer development and related mechanisms, and the prospects for therapeutic applications.

Harnessing the power within: engineering the microbiome for enhanced gynecologic health

Graphical abstract

Abstract

Although numerous studies have demonstrated the impact of microbiome manipulation on human health, research on the microbiome's influence on female health remains relatively limited despite substantial disease burden. In light of this, we present a selected review of clinical trials and preclinical studies targeting both the vaginal and gut microbiomes for the prevention or treatment of various gynecologic conditions. Specifically, we explore studies that leverage microbiota transplants, probiotics, prebiotics, diet modifications, and engineered microbial strains. A healthy vaginal microbiome for females of reproductive age consists of lactic acid-producing bacteria predominantly of the Lactobacillus genus, which serves as a protective barrier against pathogens and maintains a balanced ecosystem. The gut microbiota's production of short-chain fatty acids, metabolism of primary bile acids, and modulation of sex steroid levels have significant implications for the interplay between host and microbes throughout the body, ultimately impacting reproductive health. By harnessing interventions that modulate both the vaginal and gut microbiomes, it becomes possible to not only maintain homeostasis but also mitigate pathological conditions. While the field is still working toward making broad clinical recommendations, the current studies demonstrate that manipulating the microbiome holds great potential for addressing diverse gynecologic conditions.

Lay summary

Manipulating the microbiome has recently entered popular culture, with various diets thought to aid the microbes that live within us. These microbes live in different locations of our body and accordingly help us digest food, modulate our immune system, and influence reproductive health. The role of the microbes living in and influencing the female reproductive tract remains understudied despite known roles in common conditions such as vulvovaginal candidiasis (affecting 75% of females in their lifetime), bacterial vaginosis (25% of females in their lifetime), cervical HPV infection (80% of females in their lifetime), endometriosis (6-10% of females of reproductive age), and polycystic ovary syndrome (10-12% of females of reproductive age). Here, we review four different approaches used to manipulate the female reproductive tract and gastrointestinal system microbiomes: microbiota transplants, probiotics, prebiotics, and dietary interventions, and the use of engineered microbial strains. In doing so, we aim to stimulate discussion on new ways to understand and treat female reproductive health conditions.

The interplay between HPV, other Sexually Transmissible Infections and genital microbiome on cervical microenvironment (MicroCervixHPV study)

Background

The importance of Cervicovaginal Microbiota in protecting against infections (such as HPV) is already well established, namely through Lactobacillus spp., as well as the mechanism through which HPV leads to Cervical Neoplasia. However, it is not possible to classify HPV as a complete carcinogen. Thus, the importance of exploring Cervicovaginal dysbiosis with the intention of deciphering this interaction with HPV, takes on greater relevance. The main objectives of this study were: 1) Comparison of the MCV composition of women with or without HPV and women with ASCUS or LSIL; 2) Characterization of cytokines present in the vaginal microenvironment; 3) Evaluation of the blood count ratios as prognostic systemic inflammatory biomarkers; 4) Correlation between MCV, HPV serotypes and cytokines.

Methods

This was a retrospective, observational, multicenter, cross-sectional study. CVM analysis was performed by isolation RNA and sequencing on a NGS platform. Cytokine concentrations of CVM were obtained through Multiplex platform. Statistical analysis was performed in SPSS v 26.0. An α of 0.05 was considered statistically significant.

Results

Highlighting the core of the study, CVM types of CST I and CST IV were found to influence the emergence of cervical lesions. Neutrophil-to-Lymphocyte ratio was found to impact the prognosis of ASCUS. Within CVM, Lactobacillus prevent the growth of other CST IV species, while the latter express symbiotic relationships with each other and show affinity for specific HPV serotypes. At last, RANTES chemokine is significantly elevated in cervicovaginal infections.

Conclusion

The importance of using vaginal cytokine profiles and CVM is highlighted in the hypothesis of prevention of Cervical Neoplasia development, as well as in its use as a prognostic biomarker. Taken together, these insights are one step closer to personalized medicine.

Gynecological Cancers and Microbiota Dynamics: Insights into Pathogenesis and Therapy

In recent years, the relationship between the microbiota and various aspects of health has become a focal point of scientific investigation. Although the most studied microbiota concern the gastrointestinal tract, recently, the interest has also been extended to other body districts. Female genital tract dysbiosis and its possible impact on pathologies such as endometriosis, polycystic ovary syndrome (PCOS), pelvic inflammatory disease (PID), and gynecological cancers have been unveiled. The incursion of pathogenic microbes alters the ecological equilibrium of the vagina, triggering inflammation and compromising immune defense, potentially fostering an environment conducive to cancer development. The most common types of gynecological cancer include cervical, endometrial, and ovarian cancer, which occur in women of any age but especially in postmenopausal women. Several studies highlighted that a low presence of lactobacilli at the vaginal level, and consequently, in related areas (such as the endometrium and ovary), correlates with a higher risk of gynecological pathology and likely contributes to increased incidence and worse prognosis of gynecological cancers. The complex interplay between microbial communities and the development, progression, and treatment of gynecologic malignancies is a burgeoning field not yet fully understood. The intricate crosstalk between the gut microbiota and systemic inflammation introduces a new dimension to our understanding of gynecologic cancers. The objective of this review is to focus attention on the association between vaginal microbiota and gynecological malignancies and provide detailed knowledge for future diagnostic and therapeutic strategies.

Uterine fibroids and longitudinal profiles of the vaginal microbiota in a cohort presenting for transvaginal ultrasound

Bacterial vaginosis, characterized in part by low levels of vaginal Lactobacillus species, has been associated with pro-inflammatory cytokines which could fuel uterine fibroid development. However, prior work on the associations between uterine fibroids and vaginal bacteria is sparse. Most studies have focused on assessment of individual taxa in a single sample. To address research gaps, we sought to compare short, longitudinal profiles of the vaginal microbiota in uterine fibroid cases versus controls with assessment for hormonal contraceptives (HCs), a possible confounder associated with both protection from fibroid development and increases in Lactobacillus-dominated vaginal microbiota. This is a secondary analysis of 83 reproductive-age cisgender women who presented for transvaginal ultrasound (TVUS) and self-collected mid-vaginal swabs daily for 1-2 weeks before TVUS (Range: 5-16 days, n = 697 samples). Sonography reports detailed uterine fibroid characteristics (N = 21 cases). Vaginal microbiota was assessed by 16S rRNA gene amplicon sequencing and longitudinal microbiota profiles were categorized by hierarchical clustering. We compared longitudinal profiles of the vaginal microbiota among fibroid cases and controls with exact logistic regression. Common indications for TVUS included pelvic mass (34%) and pelvic pain (39%). Fibroid cases tended to be older and report Black race. Cases less often reported HCs versus controls (32% vs. 58%). A larger proportion of cases had low-Lactobacillus longitudinal profiles (48%) than controls (34%). In unadjusted analysis, L. iners-dominated and low-Lactobacillus profiles had higher odds of fibroid case status compared to other Lactobacillus-dominated profiles, however these results were not statistically significant. No association between vaginal microbiota and fibroids was observed after adjusting for race, HC and menstruation. Results were consistent when number of fibroids were considered. There was not a statistically significant association between longitudinal profiles of vaginal microbiota and uterine fibroids after adjustment for common confounders; however, the study was limited by small sample size.

Anogenital distribution of mucosal HPV in males and females before and after renal transplantation

INTRODUCTION

Immunosuppressive drugs taken by transplant recipients may favor HPV infection at anogenital sites. HPV-type prevalence was studied in males and females before and after renal transplantation.

PATIENTS AND METHODS

Anal, cervical and penile samples were taken from 62 patients before transplantation and from 41 patients after transplantation. HPV DNA was investigated using the INNO-LiPA HPV genotyping extra test and HPV-type distribution determined.

RESULTS

Before transplantation, up to 30% of analyzed samples harbored HPV DNA, with the highest prevalence found in cervical specimens (60%). After transplantation, a trend toward HPV clearance was observed in females. By contrast, a trend toward incident infections by a wide variety of HPV genotypes at the penis and anal level was documented in men.

CONCLUSION

High prevalence of HPV at anogenital sites was documented before and after renal transplantation. Immunosuppressive drugs taken after transplantation may impact HPV acquisition or reactivation, especially in males. Special attention should be paid in view of preventing HPV-associated diseases in this vulnerable population.

The microbiome as a biomarker of anal precancerous lesions in people with HIV

PURPOSE OF REVIEW

Early detection and treatment of human papillomavirus (HPV)-related anal dysplasia in some high-risk groups can help anal cancer prevention, but new tools to improve diagnostic and risk assessment are needed. Here, we aim to discuss the evidence on the role of the microbiome as a potential biomarker for anal high-grade squamous intraepithelial lesions (HSILs) in people with HIV (PWH).

RECENT FINDINGS

This review covers relevant studies on the links between the microbiome and HPV infection, cervical dysplasia/cancer, and anal HPV disease. It focuses on anal samples and precancerous lesions.

SUMMARY

The review highlights the promising potential of the anal microbiome as a novel biomarker for precancerous lesions in people with HIV, while also discussing limitations and future research needs.

Cervicovaginal microbiota long-term dynamics and prediction of different outcomes in persistent human papillomavirus infection

Persistent human papillomavirus (HPV) infection can lead to cervical intraepithelial neoplasia (CIN) and cervical cancer, posing serious threats to the health of women. Although the cervicovaginal microbiota is strongly associated with CIN, the dynamics of the microbiota during CIN development are unknown. In this retrospective cohort study, we analyzed 3-year longitudinal data from 72 patients diagnosed with a persistent HPV infection almost all caused by high-risk HPV types. Patients were categorized into groups with HPV persistent infection (n = 37), progression to CIN (n = 16), and CIN regression (n = 19) based on infection outcome during the follow-up period. Furthermore, 16S rRNA gene sequencing was performed on consecutively collected cervical samples to explore the composition and dynamics of the cervicovaginal microbiota during the development and regression of CIN. Our results showed that the composition of the cervicovaginal microbiota varied among women with different HPV infection outcomes and remained relatively stable during the follow-up period. Notably, the serial follow-up data showed that these microbial alterations were present for at least 1-2 years and occurred before pathologic changes. In addition, microbial markers that were highly discriminatory for CIN progression or regression were identified. This study provides evidence for a temporal relationship between changes in the cervicovaginal microbiota and the development of CIN, and our findings provide support for future microbial intervention strategies for CIN.

Human papillomavirus and cervical cancer in the microbial world: exploring the vaginal microecology

The vaginal microbiota plays a crucial role in female reproductive health and is considered a biomarker for predicting disease outcomes and personalized testing. However, its relationship with human papillomavirus (HPV) infection and cervical cancer is not yet clear. Therefore, this article provides a review of the association between the vaginal microbiota, HPV infection, and cervical cancer. We discuss the composition of the vaginal microbiota, its dysbiosis, and its relationship with HPV infection, as well as potential mechanisms in the development of cervical cancer. In addition, we assess the feasibility of treatment strategies such as probiotics and vaginal microbiota transplantation to modulate the vaginal microbiota for the prevention and treatment of diseases related to HPV infection and cervical cancer. In the future, extensive replication studies are still needed to gain a deeper understanding of the complex relationship between the vaginal microbiota, HPV infection, and cervical cancer, and to clarify the role of the vaginal microbiota as a potential biomarker for predicting disease outcomes, thus providing a theoretical basis for personalized testing.

Patient characteristics and factors contributing to recurrence of bacterial vaginosis presented in primary care

BACKGROUND

Bacterial vaginosis (BV) is a common problem in primary care. BV symptoms often have a negative impact on patients' quality of life and may predispose to gynaecological problems. Some patients experience recurring episodes of BV. This study's objective is to identify possible factors that may be associated with BV recurrence and describe the characteristics of these patients and interventions performed by general practitioners.

METHODS

In this retrospective cohort study, we used data from a primary care registration network in the Netherlands in the period 2015-2020. We analysed differences between patients with recurrent BV and patients with a single episode of BV in terms of characteristics and interventions performed by general practitioners.

RESULTS

We found that patients with recently prescribed antibiotics, and a medical history of sexually transmitted infections and/or Candidiasis significantly more often presented with recurrent BV. Patients with recurrent BV had more remote consultations and less in-person consultations than single-episode patients. The reason for encounter was more often a request for medication. Regarding GPs' diagnostic and therapeutic interventions, microbiological tests were more frequently performed in recurrent BV patients. Moreover, most patients in both groups were prescribed oral metronidazole most frequently.

CONCLUSIONS

Our findings might help GPs to better recognise patients at risk of recurrence. GPs could re-evaluate their approach to the diagnosis and treatment of recurrent BV, opting for in-person consultation and using standardised diagnostic criteria and microbiological testing in patients with recurrent complaints. Antibiotic use for other conditions in these patients may lead to new BV episodes.

Vaginal microecological changes of different degrees of cervical lesions in Hakka women in Meizhou City

Research shows an association between vaginal microbiota and the development of cervical cancer, but the role of altered microbiota in cancer development remains controversial. In this study, we attempted to reveal the vaginal microecological changes in cervical lesions by 16S rRNA gene sequencing. Vaginal secretions were collected from Hakka women in Meizhou City, Guangdong Province, China. The diversity, composition and the correlations among species of the vaginal microbiota were determined by sequencing the bacterial 16S rRNA gene. The microbial functional abundance was detected via KEGG and COG (Clusters of Orthologous Groups). The results showed that the Cancer group was characterised by evident changes in the composition of the vaginal microbiota, increased alpha diversity, and altered community structure distribution and microbial interaction network. Linear discriminant analysis (LDA) effect size showed that 21 bacterial species were abundant in the Cancer group. In addition, the loss of Lactobacillus stimulated other flora proliferation, resulting in a microecological disturbance. KEGG and COG analysis indicated the cancer group is mainly concentrated in energy metabolism. In short, the vaginal microecology of Hakka women in Meizhou City presents with different degrees of cervical lesions, and the flora imbalance is an important factor in the development of cervical cancer.IMPACT STATEMENTWhat is already known on this subject? Cervical cancer is one of the most common gynecological malignancies worldwide and has become a prominent public health problem.What the results of this study add? Our study showed that the type of vaginal community status of Hakka women in Meizhou area was characterised by L. Iners predominates, and the gradual loss of Lactobacillus dominance in vaginal bacteria is key to microecological imbalance.What the implications are of these findings for clinical practice and/or further research? Disturbances in vaginal microecology can stimulate energy metabolism and lipid metabolism to induce cervical cancer development.

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.

High-risk human papillomavirus prevalence among South African women diagnosed with other STIs and BV

INTRODUCTION

Human papillomavirus (HPV) infection is a leading cause of cervical cancer. Although this relies on infection and persistence of HPV in epithelial cells, often occurring in the context of other sexually transmitted infections (STIs) and bacterial vaginosis (BV), data on the relationships between these and their relative effects on epithelial barrier integrity in women remain sparse. This study describes the epidemiology of HPV combined with STI and/or BV prevalence and the relative impact on matrix metalloproteinases (MMPs) among South African women.

METHODS

Roche Linear Array was used for HPV genotyping in menstrual cup pellets of 243 HIV-negative women participating in the CAPRISA 083 cohort study. Vulvovaginal swabs were tested for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis using Xpert® CT/NG assay and lateral flow assay, and Gram staining was performed to diagnose BV using Nugent scoring criteria. Concentrations of 5 MMPs were measured in menstrual cup supernatants by multiplexed ELISA. Fisher's exact tests, Mann-Whitney U tests, and multivariable regression models determined associations between HPV infection, STI and/or BV, and MMP concentrations.

RESULTS

HPV was prevalent in 34% of women (83/243; median 23 years, interquartile range (IQR) 21-27 years). Low-risk (lr) (71%, 59/83) and high-risk (hr)-HPV infections (54.2%, 45/83) were common. Hr-HPV was frequently detected in STI and/or BV-positive women compared to women without STIs or BV (p = 0.029). In multivariable analysis, BV was associated with increased odds of hr-HPV detection (OR: 2.64, 95%CI: 1.02-6.87, p = 0.046). Furthermore, Gardasil®9 vaccine-type strains were more frequently detected in women diagnosed with STI and/or BV (55.2%, 32/58 vs 24%, 6/25; p = 0.009). Among STI and/or BV-positive women, HPV detection was significantly associated with increased MMP-10 concentrations (b = 0.55, 95% CI 0.79-1.01; p = 0.022).

CONCLUSION

Most women with hr-HPV had another STI and/or BV, emphasizing an urgent need for STI and BV screening and intensive scale-up of cervical cancer screening and HPV vaccination programmes. Furthermore, the study highlights the need for more extensive research to confirm and understand the relationship between HPV infection and barrier integrity.

Comparison of vaginal microbiota between women with inflammatory bowel disease and healthy controls

BACKGROUND

The gut microbiota in patients with inflammatory bowel disease are perturbed in both composition and function. The vaginal microbiome and its role in the reproductive health of women with inflammatory bowel disease is less well described.

OBJECTIVE

We aim to compare the vaginal microbiota of women with inflammatory bowel disease to healthy controls.

METHODS

Women with inflammatory bowel disease enrolled in a longitudinal cohort study provided self-collected vaginal swabs. Healthy controls underwent provider-collected vaginal swabs at routine gynecologic exams. All participants completed surveys on health history, vulvovaginal symptoms and gastrointestinal symptoms, if applicable. Microbiota were characterized by sequencing the V4 region of the 16S rRNA gene. Associations between patient characteristics and microbial community composition were evaluated by PERMANOVA and Principal Components Analysis. Lactobacillus dominance of the microbial community was compared between groups using chi-square and Poisson regression.

RESULTS

The cohort included 54 women with inflammatory bowel disease (25 Ulcerative colitis, 25 Crohn's Disease) and 26 controls. A majority, 72 (90%) were White; 17 (31%) with inflammatory bowel disease and 7 (27%) controls were postmenopausal. The composition of the vaginal microbiota did not vary significantly by diagnosis or severity of inflammatory bowel disease but did vary by menopausal status (p = 0.042). There were no significant differences in Shannon Diversity Index between healthy controls and women with IBD in premenopausal participants. There was no difference in proportion of Lactobacillus dominance according to diagnosis in premenopausal participants. A subgroup of postmenopausal women with Ulcerative colitis showed a significant higher alpha diversity and a lack of Lactobacillus dominance in the vaginal microbiome.

CONCLUSIONS

Menopausal status had a larger impact on vaginal microbial communities than inflammatory bowel disease diagnosis or severity.

Characteristics of vaginal microbiota in various cervical intraepithelial neoplasia: a cross-sectional study

BACKGROUND

Precancerous lesions of cervical cancer exhibit characteristics indicative of natural progression. To prevent overtreatment of patients whose cervical intraepithelial neoplasia (CIN) in regression and to predict the onset of invasive cervical cancer at an early stage, we've identified the vaginal microbiome as a potential key factor, which is associated with both HPV infection and the various cervical intraepithelial neoplasia. This study aims to investigate the microbiome characteristics of patients with various cervical intraepithelial neoplasia.

METHODS

Utilizing high-throughput 16S ribosomal RNA (16S rRNA) sequencing technology, a description of the characteristics and community composition of Vaginal Microbiota (VMB) was conducted among 692 Chinese women infected with the High-risk Human Papillomavirus (HR-HPV).

RESULTS

As the grade of the lesions increased, the proportions of Lactobacillus and Pseudomonas demonstrated a significant declining trend, while the proportions of Gardnerella, Dialister, and Prevotella significantly increased. The diversity of the VMB was more significant in high-grade CIN. Furthermore, KEGG pathway enrichment analysis indicates that high-grade cervical intraepithelial neoplasia can inhibit various pathways, including those of phosphotransferase system, transcription factors, Fructose and mannose metabolism, amino sugar and nucleotide sugar metabolism, and galactose metabolism, which may contribute to the development of early cervical cancer symptoms.

CONCLUSION

Patients with CIN exhibit a distinct vaginal microbial profile characterized by a decrease in Lactobacillus and Pseudomonas, and an increase in Gardnerella, Prevotella, and Dialister. The proliferation and diminution of these two types of microbial communities are interrelated, suggesting a mutual restraint and balance among them. Disruption of this regulatory balance could potentially lead to the onset of cervical lesions and carcinogenesis. Retrospectively registered: This study was approved by the Ethics Committee of the Beijing Chaoyang Hospital affiliated with the Capital Medical University (NO.2023-S-415).

The analysis of Lactobacillus spp. distribution in the vaginal microbiota of Polish women with abnormal Pap smear result

Introduction

A healthy vaginal microbiota is represented mainly by Lactobacillus spp. and plays a vital role in maintaining the functional balance in the vaginal environment. Scientists have drawn attention to possible correlations between the vaginal microbiome and gynecological neoplasms. Several recent studies have shown a potential link between the vaginal microbiome and the risk of developing cervical cancer from human papillomavirus (HPV) infection. This study aimed to compare the prevalence and abundance of various lactic acid bacteria species (LABs) in vaginal swabs from healthy controls and patients with abnormal Pap smear results.

Methods

The study included 100 women (79 patients with abnormal cervical Pap smear results and 21 controls) from whom vaginal swabs were collected. Real-time quantitative PCR was used to determine seven lactic acid bacteria (LAB) species and their quantities.

Results

Most patients were colonized by two Lactobacillus species, primarily Lactobacillus gasseri (93%) and L. crispatus (83%). Patient age and place of residence were associated with the diversity of LAB in the vaginal microbiota. The abundance of L. delbrueckii in the vaginal microbiota increased, whereas the abundance of L. gasseri abundance decreased, with patient age. Lactobacillus acidophilus and Limosilactobacillus fermentum were significantly more often detected in patients living in rural versus urban areas. Statistical analysis did not show any significant differences in LAB between groups of patients with various changes on smear tests.

Discussion

The degree of dysplastic changes in the endothelium or the presence of a group of atypical cervical stratified epithelial cells was not associated with significant changes in the studied vaginal bacteria.

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.

A novel approach for exploring the regional features of vaginal fluids based on microbial relative abundance and alpha diversity

Vaginal fluids are one of the most common biological samples in forensic sexual assault cases, and their characterization is vital to narrow the scope of investigation. Presently, approaches for identifying vaginal fluids in different regions are not only rare but also have certain limitations. However, the microbiome has shown the potential to identify the source of body fluids and reveal the characteristics of individuals. In this study, 16S rRNA gene high-throughput sequencing was used to characterize the vaginal microbial community from three regions, Sichuan, Hainan and Hunan. In addition, data on relative abundance and alpha diversity were used to construct a random forest model. The results revealed that the dominant genera in the three regions were Lactobacillus, followed by Gardnerella. In addition, Ureaplasma, Nitrospira, Nocardiodes, Veillonella and g-norank-f-Vicinamibacteraceae were significantly enriched genera in Sichuan, llumatobacter was enriched in Hainan, and Pseudomonas was enriched in Hunan. The random forest classifier based on combined data on relative abundance and alpha diversity had a good ability to distinguish vaginal fluids with similar dominant microbial compositions in the three regions. The study suggests that combining high-throughput sequencing data with machine learning models has good potential for application in the biogeographic inference of vaginal fluids.

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

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

Longitudinal analysis on the ecological dynamics of the cervicovaginal microbiome in hrHPV infection

The cervicovaginal microbiome (CVM) is a dynamic continuous microenvironment that can be clustered in microbial community state types (CSTs) and is associated with women's cervical health. Lactobacillus-depleted communities particularly associate with an increased susceptibility for persistence of high-risk human papillomavirus (hrHPV) infections and progression of disease, but the long-term ecological dynamics of CSTs after hrHPV infection diagnosis remain poorly understood. To determine such dynamics, we examined the CVM of our longitudinal cohort of 141 women diagnosed with hrHPV infection at baseline with collected cervical smears at two timepoints six-months apart. Here we describe that the long-term microbiome dissimilarity has a positive correlation with microbial diversity at both visits and that women with high abundance and dominance for Lactobacillus iners at baseline exhibit more similar microbiome composition at second visit than women with Lactobacillus-depleted communities at baseline. We further show that the species Lactobacillus acidophilus and Megasphaera genomosp type 1 associate with CST changes between both visits. Lastly, we also observe that Gardnerella vaginalis is associated with the stability of Lactobacillus-depleted communities while L. iners is associated with the instability of Megasphaera genomosp type 1-dominated communities. Our data suggest dynamic patterns of cervicovaginal CSTs during hrHPV infection, which could be potentially used to develop microbiome-based therapies against infection progression towards disease.

Cervicovaginal Gardnerella sialidase-encoding gene in persistent human papillomavirus infection

Disturbed vaginal microbiota have a role in the persistence of high-oncogenic-risk human papillomavirus (hrHPV) and Gardnerella spp. is closely related with this condition. Such bacteria are the major source of cervicovaginal sialidases, important for microbiota alterations. The sialidase-encoding gene nanH3 is account for their sialidase activity. Thus, a subset of 212 women positive for hrHPV at the first visit were included in the analysis of the current study aiming to compare the loads of nanH3 in cervicovaginal fluid (CFV) of women with persistent hrHPV infection and with those cleared the infection after a year. Participants were assigned to two study groups named "persistence" (n = 124, 53.22%) or "clearance" (n = 88, 37.77%), according to the HPV status upon enrollment and follow-up. Absolute quantification of nanH3 gene was performed using quantitative real-time PCR (qPCR). Persistence and clearance group did not show statistical difference in the load of nanH3 gene (p = 0.19). When considering the subset of women with HPV16, differences in number of copies of nanh3 gene was observed between the persistent (7.39E+08 copies/μL) and clearance group (2.85E+07 copies/μL) (p = 0.007). Therefore, baseline loads of nanH3 gene is increased in women that persist with cervical HPV16 infection after 12 months.

Cervical Microbiota Influences Cytokine Diversity in Cervical Intraepithelial Neoplasia among Rural Women in the Akyemansa District of Ghana

Background

In recent times, cervical dysbiosis which mostly causes and aggravates infections is highlighted for its role in immune modulation in cervical dysplasia, which promotes the shifting of Th1 phenotype immunity to Th2 phenotype immunity. This study therefore estimated and compared the levels of circulatory IL-4, IL-6, IL-10, TNF-α, and IFN-γ cytokines among adult women identified to have different grades of cervical intraepithelial neoplasia (CIN) and with cervicovaginal infection.

Methods

A total of 157 participants were recruited from the Akyemansa District of Ghana, and cervical swabs and blood samples were taken. The Pap smear test, microbiological culture, and ELISA were employed for cytology analysis, bacteria isolation, and identification and estimation of IL-4, IL-6, IL-10, TNF-α, and IFN-γ cytokines, respectively.

Results

Overall, 14/157 (8.9%) had CIN with 7.6% having CIN 1 and 1.3% having CIN 2. The main predictor for CIN was age above 46 years (OR 11.16, 95% CI: 2.4-51.8). Bacterial vaginosis (p = 0.003) and Candida infection (p = 0.012) were significantly higher in CIN. Again, Staphylococcus aureus (60% vs. 17.6%, p = 0.005), Citrobacter sp. (40.0% vs. 13.2%, p = 0.017), and Morganella morganii (40.0% vs. 4.4%, p = 0.002) isolates were significantly higher in CIN-positive participants. IL-10 and TNF-α concentrations were elevated in participants with CIN 1+ (TNF-α NIL vs. CIN 1+ only, p < 0.05) while IL-6 was decreased among participants with CIN 1+. In the presence of vaginal infection, TNF-α decreased among CIN 1+ participants while IL-10 remained elevated.

Conclusion

The findings of this study suggest that cervical dysbiosis causes immune suppression, which creates a suitable microenvironment for the development of CIN.

Pre- and post-LEEP: analysis of the female urogenital tract microenvironment and its association with sexual dysfunction

Background

The loop electrosurgical excision procedure (LEEP) to treat cervical dysplasia (CD) is known to alter the cervical microbiota, the community of bacteria that play a central role in female genital health. Perturbations to the microbiota of the female urogenital tract (FUT), including the urethra, vagina, and cervix, have been linked with symptoms of sexual dysfunction (SD), though correlations among LEEP, the microenvironment, and SD have not yet been described.

Aims

To characterize the FUT microbiota before and after LEEP and investigate possible associations with SD.

Methods

Females undergoing LEEP for CD were recruited to participate in the study. Urinary samples and vaginal and cervical swabs were collected immediately before and 3 months after treatment. Bacterial communities were characterized by 16S rRNA next-generation sequencing. Self-report surveys assessing demographics, medical history, and sexual function were completed at the same intervals.

Outcomes

Microbiota taxonomy and Female Sexual Function Index (FSFI) scores.

Results

Alpha diversity revealed a significant decrease in species richness in the FUT microbiota post-LEEP. Beta diversity demonstrated significant differences among the cervical, urinary, and vaginal microenvironments pre- and post-LEEP. Lactobacillus spp were the dominant microbial genus in the cervical microenvironment pre- and post-LEEP. Although the vaginal and urinary microenvironments were characterized by Prevotella pre-LEEP, they were colonized by Lactobacillus post-LEEP. Following LEEP, some participants experienced a significant increase in proinflammatory bacteria, including the genera Gardnerella, Megasphaera, Sneathia, Parvimonas, and Peptostreptococcus. Others experienced significant decreases in inflammatory and protective bacteria post-LEEP, including Butyricicoccus, Terriporobacter, Intestinimonas, and Negativibacillus. Overall there were no significant changes in pre- and post-LEEP FSFI scores. However, post-LEEP FSFI scores were seemingly associated with changes in inflammatory bacteria in some participants.

Clinical Implications

There is an overall reduction in FUT microbiota dysbiosis post-LEEP. However, we show variability as some participants experienced persistent dysbiosis of FUT microbiota and elevated FSFI scores, suggesting that therapies to treat dysbiosis of FUT microbiota may reduce FSFI scores, thereby improving SD symptoms.

Strengths and Limitations

We demonstrate novel associations among urogenital sites, microbiota changes, LEEP, and SD. The small sample size and inability of species classification are limitations.

Conclusion

Diverse inflammatory microbiota characterizes CD in the FUT, and LEEP mostly returns microenvironments to a healthy state. However, some participants have persistent inflammatory bacteria post-LEEP, suggesting a non-uniform healing response. This study provides an impetus for future longitudinal studies to monitor and restore FUT microenvironments post-LEEP, aimed at mitigating postoperative SD symptoms.

Dysbiotic Co-Factors in Cervical Cancer. How the Microbiome Influences the Development of Cervical Intraepithelial Neoplasia (CIN)

Human papillomavirus (HPV) infection is a necessary but not sufficient condition for the development of cervical cancer. The dysbiotic shift in the cervicovaginal microbiome appears to be a major co-factor in carcinogenesis. New analytical methods, such as next-generation sequencing (NGS), can be used to detect all of the vaginal microorganisms present and therefore identify individual therapeutic options. The relationship of bacterial vaginosis and carcinogenesis, as well as possible indications for the use of microbiome analysis, will be discussed.

Exploring Microbiota Diversity in Cervical Lesion Progression and HPV Infection through 16S rRNA Gene Metagenomic Sequencing

(1) Background: Cervical cancer is a significant health concern, with the main cause being persistent infection with high-risk Human Papillomavirus (hrHPV). There is still no evidence for why viral persistence occurs in some women, but recent studies have revealed the interplay between cervical microbiota and hrHPV. This research aimed to characterize the cervicovaginal microbiota in cervical lesion progression and HPV infection status. (2) Methods: This study included 85 cervical specimens from women from the north-eastern region of Romania. DNA was isolated from cervical secretion for HPV genotyping and 16S ribosomal RNA gene NGS sequencing. (3) Results: Our study revealed a distinct pattern within the studied group when considering Lactobacillus species, which differs from findings reported in other populations. Specifically, the presence of Lactobacillus iners coupled with the absence of Lactobacillus crispatus alongside Atopobium spp., Prevotella spp., and Gardnerella spp. could serve as defining factors for severe cervical lesions. The results also showed a significant association between microbiota diversity, HPV infection, and cervical lesion progression. (4) Conclusions: As the microbiota profile seems to vary among different populations and individuals, a deeper comprehension of its composition has the potential to develop personalized detection and treatment approaches for cervical dysplasia and cancer.

Orally administrated Lactobacillus gasseri TM13 and Lactobacillus crispatus LG55 can restore the vaginal health of patients recovering from bacterial vaginosis

Bacterial vaginosis (BV) is a common infection of the lower genital tract with a vaginal microbiome dysbiosis caused by decreasing of lactobacilli. Previous studies suggested that supplementation with live Lactobacillus may benefit the recovery of BV, however, the outcomes vary in people from different regions. Herein, we aim to evaluate the effectiveness of oral Chinese-origin Lactobacillus with adjuvant metronidazole (MET) on treating Chinese BV patients. In total, 67 Chinese women with BV were enrolled in this parallel controlled trial and randomly assigned to two study groups: a control group treated with MET vaginal suppositories for 7 days and a probiotic group treated with oral Lactobacillus gasseri TM13 and Lactobacillus crispatus LG55 as an adjuvant to MET for 30 days. By comparing the participants with Nugent Scores ≥ 7 and < 7 on days 14, 30, and 90, we found that oral administration of probiotics did not improve BV cure rates (72.73% and 84.00% at day 14, 57.14% and 60.00% at day 30, 32.14% and 48.39% at day 90 for probiotic and control group respectively). However, the probiotics were effective in restoring vaginal health after cure by showing higher proportion of participants with Nugent Scores < 4 in the probiotic group compared to the control group (87.50% and 71.43% on day 14, 93.75% and 88.89% on day 30, and 77.78% and 66.67% on day 90). The relative abundance of the probiotic strains was significantly increased in the intestinal microbiome of the probiotic group compared to the control group at day 14, but no significance was detected after 30 and 90 days. Also, the probiotics were not detected in vaginal microbiome, suggesting that L. gasseri TM13 and L. crispatus LG55 mainly acted through the intestine. A higher abundance of Prevotella timonensis at baseline was significantly associated with long-term cure failure of BV and greatly contributed to the enrichment of the lipid IVA synthesis pathway, which could aggravate inflammation response. To sum up, L. gasseri TM13 and L. crispatus LG55 can restore the vaginal health of patients recovering from BV, and individualized intervention mode should be developed to restore the vaginal health of patients recovering from BV.

Clinical trial registration

https://classic.clinicaltrials.gov/ct2/show/, identifier NCT04771728.

Milk and Dairy Consumption and Its Relationship With Abundance of Lactobacillus crispatus in the Vaginal Microbiota: Milk Intake and Vaginal Lactobacillus

OBJECTIVES

Diet habits, such as low milk and dairy intake, have been associated with bacterial vaginosis. Thus, the authors compared vaginal Lactobacillus crispatus abundances in women with different molecularly defined community state types (CSTs) according to the consumption of milk and/or dairy products.

METHODS

A total of 516 women from the 5 geographic regions of Brazil were included. Participants were interviewed with a structured questionnaire for assessment of milk and/or dairy intake. Vaginal samples were used for sequencing of V3-V4 regions of the 16S ribosomal RNA gene for further determination of L. crispatus relative abundance (RA) and clustering into 1 of the 5 CSTs (CSTI-CSTV), as firstly described by Ravel et al. (2011). The nonparametric Mann-Whitney test was used to compare L. crispatus RA within the most representative CSTs ( L. crispatus -dominant CSTI, Lactobacillus iners -dominant CSTIII, and Lactobacillus -depleted CSTIV) in this population, according to the frequency of milk and/or dairy intake.

RESULTS

The prevalence of CSTI was 33.3% ( n = 172), CSTIII was 39% ( n = 201), and CSTIV was 27.7% ( n = 143). Among the participants with CSTIII, higher L. crispatus RA was observed for those who reported milk/dairy intake (median = 0.02; interquartile range = 0.01-0.09) than those with no consumption (median = 0.01; interquartile range = 0-0.03) ( p = .03). Such difference was not observed for participants with CSTI and CSTIV.

CONCLUSIONS

Women with vaginal microbiota dominated by L. iners who consume milk and/or dairy present increased abundances of L. crispatus . Therefore, they could benefit from L. crispatus protective properties conferring greater temporal microbiota stability and, consequently, increased protection against infections.

Correlation between vaginal flora and cervical immune function of human papilloma virus-infected patients with cervical cancer

Background

To analyse the correlation between vaginal flora and cervical immune function of HPV-infected patients with cervical cancer.

Methods

Six hundred females with genital tract infections treated in Xuzhou Hospital of Traditional Chinese Medicine from January 2014 to December 2016 were selected and divided into a high-risk HPV group (n=246) and a control group (n=354). The vaginal flora and human T lymphocyte subsets (CD3+, CD4+, CD8+) were detected. Multivariate logistic regression analysis was performed to explore the risk factors for HPV infection.

Results

The numbers of CD4+ and CD4+/CD8+ T cells of the high-risk HPV group were significantly lower than those of the control group (P<0.05). The two groups had similar numbers of CD3+ and CD8+ T cells. In the high-risk HPV group, the positive rates of Lactobacillus, Chlamydia trachomatis, Mycoplasma hominis, mycetes, Ureaplasma urealyticum and bacterial vaginosis were significantly higher than those of the control group (P<0.05). There was no significant difference in the positive rates of trichomonads between the two groups. Multivariate logistic regression analysis revealed that C. trachomatis and U. urealyticum were independent risk factors for high-risk HPV infection (P<0.05).

Conclusion

High-risk HPV infection in patients with cervical cancer was associated with vaginal flora and immune function. C. trachomatis and U. urealyticum were independent risk factors for high-risk HPV infection.

Bacterial vaginosis: a review of approaches to treatment and prevention

Bacterial vaginosis (BV) is a common cause of vaginitis worldwide and is associated with serious reproductive health outcomes, including increased risk of preterm birth, sexually transmitted infections, and pelvic inflammatory disease. The current and only FDA-approved treatment regimens for BV are antibiotics, such as metronidazole and clindamycin. Antibiotics provide a short-term cure for bacterial vaginosis; however, fail to provide a consistent long-term cure for many women. Fifty to eighty percent of women experience a BV recurrence within a year of completing antibiotic treatment. This may be because after antibiotic treatment, beneficial strains of Lactobacillus, such as L. crispatus, do not recolonize the vagina. In the absence of an effective long-term cure, patients, providers, and researchers are exploring different approaches to treatment and prevention, resulting in a rapid evolution of perspectives on BV pathogenesis and approaches to management. Current areas of investigation for BV management include probiotics, vaginal microbiome transplantation, pH modulation, and biofilm disruption. Behavioral modifications that may help include smoking cessation, condom use and hormonal contraception. Additional strategies considered by many people include dietary modification, non-medical vaginally applied products, choice of lubricant, and treatments from medical practices outside of allopathic medicine. This review aims to provide a comprehensive and up to date outline of the landscape of ongoing and potential treatment and prevention strategies for BV.

Relationship between Human Papillomavirus Status and the Cervicovaginal Microbiome in Cervical Cancer

Uterine cervical cancer (CC) is a complex, multistep disease primarily linked to persistent infection with high-risk human papillomavirus (HR-HPV). However, it is widely acknowledged that HR-HPV infection alone cannot account for the formation and progression of CC. Emerging evidence suggests that the cervicovaginal microbiome (CVM) also plays a significant role in HPV-related CC. Certain bacteria, such as Fusobacterium spp., Porphyromonas, Prevotella, and Campylobacter, are currently being considered as potential microbiomarkers for HPV-positive CC. However, the composition of the CVM in CC is inconsistent; thus, further studies are needed. This review comprehensively discusses the complex interplay between HPV and the CVM in cervical carcinogenesis. It is postulated that the dynamic interaction between HPV and the CVM creates an imbalanced cervicovaginal microenvironment that triggers dysbiosis, enhances HPV persistence, and promotes cervical carcinogenesis. Moreover, this review aims to provide updated evidence on the potential role of bacteriotherapy, particularly probiotics, in the treatment of CC.

The interplay between human papillomavirus and vaginal microbiota in cervical cancer development

Over the past few decades, we have grown accustomed to the idea that human papillomavirus can cause tumors. The genetic and environmental factors that make the difference between elimination of viral infection and the development of cancer are therefore an area of active investigation at present. Microbiota has emerged as an important factor that may affect this balance by increasing or decreasing the ability of viral infection to promote. The female reproductive system has its specific microbiota that helps to maintain health and prevent infection with pathogens. In contrast to other mucosal sites, the vaginal microbiota typically has low diversity and contains few Lactobacillus spp. which by using high-throughput 16s rRNA gene sequencing, classified into five different community state types. According to emerging information, increased diversity of vaginal microbiota and reduced abundance of Lactobacillus spp. contribute to HPV acquisition, persistence, and development of cervical cancer. In this review, the role of normal female reproductive tract microbiota in health, mechanisms which dysbiosis can cause diseases through interaction with microbes and several therapeutic approaches were addressed.

Covariates of vaginal microbiota and pro-inflammatory cytokine levels in women of reproductive age

This study aimed to assess the correlation between covariates of the vaginal microbiota and local levels of proinflammatory cytokines in women of reproductive age presenting four molecularly defined bacterial community-state types (CSTs). We enrolled 133 non-pregnant women who attended primary care health clinics for routine Pap-testing. Molecular profiling of vaginal microbiota was performed by V3-V4 16S rRNA sequencing. The covariates of vaginal microbiota included were: vaginal pH, total bacterial cell count, diversity (Shannon index), -richness and dominant taxa abundances. Levels of interleukin (IL)-1β, IL-6, IL-8, and tumour necrosis factor (TNF-α) were measured by enzyme-linked immunosorbent assays in supernatants of cervicovaginal fluids. Nonparametric Kruskal-Wallis test was used to compare microbiota covariates and cytokines among different CSTs. Spearman's tests were performed to assess correlations across the measured parameters. A total of 96 (72.2%) participants had CSTs dominated by Lactobacillus spp. (Lactobacillus crispatus CST I, n=38; Lactobacillus gasseri CST II, n=20; and Lactobacillus iners CST III, n=38). A total of 37 (27.8%) presented the Lactobacillus-depleted CST IV. Total bacterial count was higher in CST II (1.29E+05, 3.40E+04-6.69E+05) compared to other Lactobacillus-dominated CSTs (p=0.0003). The highest values of microbiota diversity (1.85; 0.23-2.68) and richness (27.0; 5.0-37.0) were observed in CST IV (P<0.0001). Lower levels of IL-1β were observed in CST I (5.4; 0.0-3,256) when compared to CST III (51.7; 0.0-2,616) and to CST IV (56.2; 0.0-3,407) (P=0.008). Levels of IL-6 were higher in CST II (4.13; 0-131.4) than in CST IV (0.0-58.27) (P=0.02). Correlation tests showed an overall distinct profile of CST II when compared to other Lactobacillusdominated CSTs, particularly regarding the correlation between total bacterial load and cytokines (r>0.39). In conclusion, this study provides evidence of a single pro-inflammatory signature of L. gasseri-dominated microbiota in response to bacterial load. Further studies evaluating a broader range of inflammation markers are warranted.

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.

Epidemiologic Evidence on the Role of Lactobacillus iners in Sexually Transmitted Infections and Bacterial Vaginosis: A Series of Systematic Reviews and Meta-Analyses

ABSTRACT

Although Lactobacillus crispatus -dominated vaginal microbiotas are thought to protect against bacterial vaginosis (BV) and sexually transmitted infections, the role of Lactobacillus iners -dominated microbiotas is less clear. To better understand the impact of L. iners on common cervicovaginal infections, we conducted systematic reviews of the associations between L. iners compared with L. crispatus and 8 outcomes: Chlamydia trachomatis (Ct), BV, human papillomavirus, cervical dysplasia, human immunodeficiency virus, genital herpes, Trichomonas vaginalis , and Neisseria gonorrhoeae . On April 30, 2021, we searched PubMed, Embase, Cochrane Library, and Web of Science for epidemiologic studies of reproductive-age, nonpregnant, cisgender women that used marker gene sequencing to characterize vaginal microbiota composition and presented an effect estimate for the association between L. iners , compared with L. crispatus , and outcomes of interest. For outcomes with ≥3 eligible results presenting the same form of effect estimate, we conducted random-effects meta-analysis. The review protocol was registered prospectively (PROSPERO CRD42020214775). Six Ct studies were included in meta-analysis, which showed L. iners -dominated microbiotas were associated with 3.4-fold higher odds of Ct compared with L. crispatus -dominated microbiotas (95% confidence interval, 2.1-5.4). Three BV studies were included in meta-analysis, which indicated L. iners -dominated microbiotas were associated with 2.1-fold higher prevalence of BV compared with L. crispatus -dominated microbiotas (95% confidence interval, 0.9-4.9). Evidence was too sparse to perform meta-analysis for the remaining outcomes. L. iners -dominated vaginal microbiotas may be suboptimal compared with L. crispatus -dominated microbiotas for BV and Ct. These reviews highlight evidence gaps regarding the remaining outcomes and opportunities to improve epidemiologic rigor in vaginal microbiome science.

Lactobacillus iners and genital health: molecular clues to an enigmatic vaginal species

Purpose of review

Vaginal lactobacilli are recognized as important drivers of genital health including protection against bacterial vaginosis and sexually transmitted infections. Lactobacillus iners is distinct from L. crispatus, L. gasseri, and L. jensenii by its high global prevalence in vaginal microbiomes, relatively small genome, production of only L-lactic acid, and inconsistent associations with genital health outcomes. In this review, we summarize our current understanding of the role of L. iners in the vaginal microbiome, highlight the importance of strain-level consideration for this species, and explain that while marker gene-based characterization of the composition of the vaginal microbiota does not capture strain-level resolution, whole metagenome sequencing can aid in expanding our understanding of this species in genital health.

Recent findings

L. iners exists in the vaginal microbiome as a unique combination of strains. The functional repertoires of these strain combinations are likely wide and contribute to the survival of this species in a variety of vaginal microenvironments. In published studies to date, strain-specific effects are aggregated and may yield imprecise estimates of risk associated with this species.

Summary

The worldwide high prevalence of Lactobacillus iners warrants more research into its functional roles in the vaginal microbiome and how it may directly impact susceptibility to infections. By incorporating strain-level resolution into future research endeavors, we may begin to appreciate L. iners more thoroughly and identify novel therapeutic targets for a variety of genital health challenges.

Vaginal and tumor microbiomes in gynecological cancer (Review)

Cervical, ovarian and endometrial cancer are the three most common types of gynecologic cancer. As a hub, the vagina connects the site of gynecological cancer with the external environment. Lactobacilli participate in the formation of a healthy vaginal microenvironment as the first line of defense against pathogen invasion; a dysbiotic vaginal microenvironment loses its original protective function and is associated with the onset, metastasis, poor efficacy and poor prognosis of gynecological cancer. The early diagnosis of cancer is the key to improve the survival time of patients with cancer. The screening of Porphyromonas, Sneathia and Atopobium vaginae, and other microbial markers, can assist the diagnosis of gynecological cancer, and screen out the high-risk population as early as possible. With the in-depth study of the microbes in tumor tissues, reasearchers have analyzed the immunological associations of microorganisms in tumor tissues. Due to the structural-functional interconnection between the organ of gynecological tumorigenesis and the vagina, the present study aims to review the relationship between vaginal and tumor microorganisms and gynecological cancer in terms of occurrence, screening, treatment and prognosis.

Menopausal Changes in the Microbiome-A Review Focused on the Genitourinary Microbiome

A balanced interaction between the host and its microbiome is crucial to health. Research regarding the significance of the gut and vaginal microbiomes in female health is substantial. However, less data regarding the urinary microbiome are available. Interactions between the gut, vaginal, and urinary microbiomes are also currently being researched. Hormone-induced dysbiosis after menopause is believed to have effects on physical changes and health consequences. Postmenopausal changes in the gut microbiome are associated with increased short-chain fatty acids and hydrogen sulfide levels. Increased vaginal pH caused by reduced estrogen alters the vaginal microbiome, resulting in reduced levels of Lactobacillus. Such changes influence the vaginal structure and functions, contributing to the onset of genitourinary syndrome of menopause. A dysbiosis of the urinary microbiome is associated with urgency and urinary incontinence and also related to interstitial cystitis/bladder pain syndrome and neuropathic bladder. As these diseases commonly affect postmenopausal women, hormone-induced changes in the microbiome may play a role. Menopause increases the alpha diversity of the urinary microbiome and lowers the percentage of Lactobacillus in urine, and such changes precede recurrent cystitis. More research regarding the effects of changes in the urinary microbiome due to menopause on urinary tract diseases is needed.

Lactobacilli and Their Probiotic Effects in the Vagina of Reproductive Age Women

In the present narrative review, the probiotic effects of vaginal Lactobacillus spp. are described in detail, covering the importance of the differential production of lactic acid, the lactic acid D/L isoforms, the questionable in vivo effect of hydrogen peroxide, as well as bacteriocins and other core proteins produced by vaginal Lactobacillus spp. Moreover, the microbe–host interaction is explained with emphasis on the vaginal mucosa. To understand the crucial role of Lactobacillus spp. dominance in the vaginal microbiota, different dysbiotic states of the vagina are explained including bacterial vaginosis and aerobic vaginitis. Finally, this review takes on the therapeutic aspect of live lactobacilli in the context of bacterial vaginosis. Until recently, there was very low-quality evidence to suggest that any probiotic might aid in reducing vaginal infections or dysbiosis. Therefore, clinical usage or over the counter usage of probiotics was not recommended. However, recent progress has been made, moving from probiotics that are typically regulated as food supplements to so-called live biotherapeutic products that are regulated as medical drugs. Thus, recently, a phase 2b trial using a Lactobacillus crispatus strain as a therapeutic add-on to standard metronidazole showed significant reduction in the recurrence of bacterial vaginosis by 12 weeks compared to placebo. This may constitute evidence for a brighter future where the therapeutic use of lactobacilli can be harnessed to improve women’s health.

Analysis of the cervical microbiome in women from the German national cervical cancer screening program

PURPOSE

Cervical cancer (CC) is caused by a persistent high-risk human papillomavirus (hrHPV) infection. The cervico-vaginal microbiome may influence the development of (pre)cancer lesions. Aim of the study was (i) to evaluate the new CC screening program in Germany for the detection of high-grade CC precursor lesions, and (ii) to elucidate the role of the cervico-vaginal microbiome and its potential impact on cervical dysplasia.

METHODS

The microbiome of 310 patients referred to colposcopy was determined by amplicon sequencing and correlated with clinicopathological parameters.

RESULTS

Most patients were referred for colposcopy due to a positive hrHPV result in two consecutive years combined with a normal PAP smear. In 2.1% of these cases, a CIN III lesion was detected. There was a significant positive association between the PAP stage and Lactobacillus vaginalis colonization and between the severity of CC precursor lesions and Ureaplasma parvum.

CONCLUSION

In our cohort, the new cervical cancer screening program resulted in a low rate of additional CIN III detected. It is questionable whether these cases were only identified earlier with additional HPV testing before the appearance of cytological abnormalities, or the new screening program will truly increase the detection rate of CIN III in the long run. Colonization with U. parvum was associated with histological dysplastic lesions. Whether targeted therapy of this pathogen or optimization of the microbiome prevents dysplasia remains speculative.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Female reproductive tract microbiome and early miscarriages

Miscarriage is one of the main causes of reproductive loss, which can lead to a number of physical and psychological complications and other long-term consequences. However, the role of vaginal and uterine microbiome in such complications is poorly understood. To review the published data on the function of the female reproductive tract microbiome in the pathogenesis of early miscarriages. The articles published over the past 20 years and deposited in PubMed, Google Academy, Scopus, Elibrary, ResearchGate, and EBSCO databases were analyzed. The review presents new data on the impact of the vaginal and uterine microbiome on the local immunity, including defense against sexually transmitted infections, and its association with other factors of miscarriages. The studies on the microbiome of non-pregnant women with recurrent miscarriages in the anamnesis, patients undergoing IVF, and pregnant women with miscarriages, as well as new directions in the microbiome research are discussed. The majority of studies have demonstrated that the dominant species of the vaginal and uterine microbiome in patients with early miscarriages are non-Lactobacillus bacteria. As many of these bacteria have not previously been detected by cultural studies and their role in obstetric complications is not well defined, further research on the female reproductive tract microbiome, including the microbiome of the cervix uteri, is needed to develop new approaches for the prognosis and prevention of miscarriages.

The Vaginal Microbiome in Health and Disease-What Role Do Common Intimate Hygiene Practices Play?

The vaginal microbiome is a dynamic, sensitive microenvironment. The hallmark of a 'healthy' vaginal microbiome is currently believed to be one dominated by Lactobacillus spp., which acidifies the vaginal environment and help to protect against invading pathogens. However, a 'normal' microbiome is often difficult, if not impossible, to characterise given that it varies in response to numerous variables, including pregnancy, the menstrual cycle, contraceptive use, diet, ethnicity, and stress. A Lactobacillus-depleted microbiome has been linked to a variety of adverse vaginal health outcomes, including preterm birth (PTB), bacterial vaginosis (BV), and increased risk of sexually transmitted infections. The latter two of these have also been associated with feminine intimate hygiene practices, many of which are practised without any evidence of health benefits. The most extensively studied practice is vaginal douching, which is known to cause vaginal dysbiosis, predisposing women to BV, pelvic inflammatory disease, and PTB. However, little is known of the impact that intimate hygiene practices and associated products have on the vaginal microbiome. This review aims to outline the major factors influencing the vaginal microbiome and common vaginal infections, as well as to summarise current research surrounding the impact of hygiene products and practices on the vaginal microbiome.

Changes in vaginal microbiome after focused ultrasound treatment of high-risk human papillomavirus infection-related low-grade cervical lesions

BACKGROUND

In this study, the changes of vaginal microbiome after focused ultrasound (FU) treatment were evaluated to explore the possible mechanism of FU in the treatment of high-risk human papillomavirus (HR-HPV) infection.

METHODS

This study was nested in the FU arm of a prospective cohort study. A total of 37 patients diagnosed with HR-HPV infection-related cervical low-grade squamous intraepithelial lesion (LSIL) who met the inclusion criteria were enrolled in this study from October 2020 to November 2021, and these patients were treated with FU. We used 16S ribosomal RNA (16S rRNA) gene amplicon sequencing to profile the vaginal microbiota composition of patients before and 3 months after FU treatment.

RESULTS

After FU treatment, HR-HPV was cleared in 24 patients, with a clearance rate of 75.0% (24/32). Lactobacillus iners was the predominant species among all samples. No significant difference was found in alpha-diversity index before and 3 months after FU treatment (P > 0.05), but the rarefaction curves showed that the vaginal microbial diversity before FU treatment was higher than that after FU treatment. Linear discriminant analysis (LDA) effect size (LEfSe) showed that Bifidobacterium contributed the most to the difference between the two groups at the genus level, and the abundance after FU treatment was significantly higher than that before treatment (P = 0.000).

CONCLUSIONS

The decrease of vaginal microbial diversity may be related to the clearance of HR-HPV infection, and FU treatment contributed to the decrease of vaginal microbial diversity. Increased Bifidobacterium abundance in the vaginal microbiome may be associated with clearance of HR-HPV infection, and FU treatment may contribute to the increase in Bifidobacterium abundance.

TRIAL REGISTRATION NUMBER

 This study was registered in the Chinese Clinical Trial Registry on 23/11/2020 (ChiCTR2000040162).