The vaginal microbiota, human papillomavirus infection and cervical intraepithelial neoplasia: what do we know and where are we going next?

Role of the vaginal microbiome in miscarriage: exploring the relationship

Miscarriage is a devastating pregnancy loss that affects many women worldwide. It is characterized as a spontaneous miscarriage that occurs before 20 weeks of gestation which affects more than 25% of pregnancies. While the causes of miscarriage are complex and multifactorial, recent research has suggested a potential role of the vaginal microbiota. The vaginal microbiome is a dynamic ecosystem of microbes that are essential for preserving vaginal health and avoiding infections. Vaginal dysbiosis has been accompanied with numerous adverse pregnancy complications, such as preterm birth. However, the effect of the vaginal microbiome in miscarriage is not fully understood. This review aims to investigate the link between vaginal microbiota and miscarriage. Also, we investigate the various mechanisms through which the vaginal microbiota may affect miscarriage. Additionally, we examine the implications of these research findings, specifically the possibility of vaginal microbiome screening and targeted interventions to prevent miscarriage.

Vaginal microbiome in obesity and its impact on reproduction

A number of reproductive outcomes have been increasingly found to be affected by the vaginal microbiota. Obesity has become a global epidemic, affecting increasing numbers of reproductive-age women, and has been shown to be a risk factor for a number of adverse female health outcomes. A healthy vaginal microbiome is characterized by Lactobacillus-dominance, in particular Lactobacillus crispatus; obesity has been found to be associated with higher diversity and a lower likelihood of Lactobacillus-dominance. In this review, we summarize the evidence on the vaginal microbiome in obese women and the impact on reproductive outcomes such as conception rates, early pregnancy, and preterm birth. We further explore the mechanisms by which obesity may result in an altered microbial composition and highlight future avenues for therapeutic targeting of the vaginal microbiota.

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.

Risk factors for human papillomavirus infection, cervical intraepithelial neoplasia and cervical cancer: an umbrella review and follow-up Mendelian randomisation studies

BACKGROUND

Persistent infection by oncogenic human papillomavirus (HPV) is necessary although not sufficient for development of cervical cancer. Behavioural, environmental, or comorbid exposures may promote or protect against malignant transformation. Randomised evidence is limited and the validity of observational studies describing these associations remains unclear.

METHODS

In this umbrella review, we searched electronic databases to identify meta-analyses of observational studies that evaluated risk or protective factors and the incidence of HPV infection, cervical intra-epithelial neoplasia (CIN), cervical cancer incidence and mortality. Following re-analysis, evidence was classified and graded based on a pre-defined set of statistical criteria. Quality was assessed with AMSTAR-2. For all associations graded as weak evidence or above, with available genetic instruments, we also performed Mendelian randomisation to examine the potential causal effect of modifiable exposures with risk of cervical cancer. The protocol for this study was registered on PROSPERO (CRD42020189995).

RESULTS

We included 171 meta-analyses of different exposure contrasts from 50 studies. Systemic immunosuppression including HIV infection (RR = 2.20 (95% CI = 1.89-2.54)) and immunosuppressive medications for inflammatory bowel disease (RR = 1.33 (95% CI = 1.27-1.39)), as well as an altered vaginal microbiome (RR = 1.59 (95% CI = 1.40-1.81)), were supported by strong and highly suggestive evidence for an association with HPV persistence, CIN or cervical cancer. Smoking, number of sexual partners and young age at first pregnancy were supported by highly suggestive evidence and confirmed by Mendelian randomisation.

CONCLUSIONS

Our main analysis supported the association of systemic (HIV infection, immunosuppressive medications) and local immunosuppression (altered vaginal microbiota) with increased risk for worse HPV and cervical disease outcomes. Mendelian randomisation confirmed the link for genetically predicted lifetime smoking index, and young age at first pregnancy with cervical cancer, highlighting also that observational evidence can hide different inherent biases. This evidence strengthens the need for more frequent HPV screening in people with immunosuppression, further investigation of the vaginal microbiome and access to sexual health services.

Vaginal microbiome community state types and high-risk human papillomaviruses in cervical precancer and cancer in North-central Nigeria

BACKGROUND

High risk human papillomaviruses (HR-HPV) have a causal role in cervical oncogenesis, and HIV-mediated immune suppression allows HR-HPV to persist. We studied whether vaginal microbiome community state types (CSTs) are associated with high-grade precancer and/or invasive cervical cancer (HSIL/ICC).

METHODS

This was a cross-sectional study of adult women with cervical cancer screening (CCS) at the Jos University Teaching Hospital (JUTH) in Jos, Nigeria, between January 2020 and February 2022. Cervical swabs underwent HPV genotyping (Anyplex™ II HPV28). Cervico-vaginal lavage (CVL) sample was collected for 16 S rRNA gene amplicon sequencing. We used multivariable logistic regression modelling to assess associations between CSTs and other factors associated with HSIL/ICC.

RESULTS

We enrolled 155 eligible participants, 151 with microbiome data for this analysis. Women were median age 52 (IQR:43-58), 47.7% HIV positive, and 58.1% with HSIL/ICC. Of the 138 with HPV data, 40.6% were negative for HPV, 10.1% had low-risk HPV, 26.8% had single HR-HPV, and 22.5% had multiple HR-HPV types. The overall prevalence of any HR-HPV type (single and multiple) was 49.3%, with a higher proportion in women with HSIL/ICC (NILM 31.6%, LSIL 46.5%, HSIL 40.8%, and 81.5% ICC; p = 0.007). Women with HIV were more likely to have HSIL/ICC (70.3% vs. 29.7% among women without HIV). In crude and multivariable analysis CST was not associated with cervical pathology (CST-III aOR = 1.13, CST-IV aOR = 1.31). However, in the presence of HR-HPV CST-III (aOR = 6.7) and CST-IV (aOR = 3.6) showed positive association with HSIL/ICC.

CONCLUSION

Vaginal microbiome CSTs were not significantly associated with HSIL/ICC. Our findings suggest however, that CST could be helpful in identifying women with HSIL/ICC and particularly those with HR-HPV. Characterization of CSTs using point-of-care molecular testing in women with HR-HPV should be studied as an approach to improve early detection and cervical cancer prevention. Future longitudinal research will improve our understanding of the temporal effect of non-optimal CST, HR-HPV, and other factors in cervical cancer development, prevention, and control.

Oral and anal microbiome from HIV-exposed individuals: role of host-associated factors in taxa composition and metabolic pathways

Evidence indicates that the microbiome plays a significant role in HIV immunopathogenesis and associated complications. This study aimed to characterize the oral and anal microbiome of Men who have Sex with Men (MSM) and Transgender Women (TGW), with and without HIV. One hundred and thirty oral and anal DNA-derived samples were obtained from 78 participants and subjected to shotgun metagenomics sequencing for further microbiome analysis. Significant differences in the microbiome composition were found among subjects associated with HIV infection, gender, sex behavior, CD4+ T-cell counts, antiretroviral therapy (ART), and the presence of HPV-associated precancerous anal lesions. Results confirm the occurrence of oncogenic viromes in this high HIV-risk population. The oral microbiome in HIV-associated cases exhibited an enrichment of bacteria associated with periodontal disease pathogenesis. Conversely, anal bacteria showed a significant decrease in HIV-infected subjects (Coprococcus comes, Finegoldia magna, Blautia obeum, Catenibacterium mitsuokai). TGW showed enrichment in species related to sexual transmission, which concurs that most recruited TGW are or have been sex workers. Prevotella bivia and Fusobacterium gonidiaformans were positively associated with anal precancerous lesions among HIV-infected subjects. The enrichment of Holdemanella biformis and C. comes was associated with detectable viral load and ART-untreated patients. Metabolic pathways were distinctly affected by predominant factors linked to sexual behavior or HIV pathogenesis. Gene family analysis identified bacterial gene signatures as potential prognostic and predictive biomarkers for HIV/AIDS-associated malignancies. Conclusions: Identified microbial features at accessible sites are potential biomarkers for predicting precancerous anal lesions and therapeutic targets for HIV immunopathogenesis.

Imbalance of Vaginal Microbiota and Immunity: Two Main Accomplices of Cervical Cancer in Chinese Women

Objective

To explore the correlation of female vaginal microbiota and immune factors with cervical cancer.

Methods

The distribution pattern difference of vaginal microbiota of four groups of women (cervical cancer, HPV-positive CIN, HPV-positive non-CIN, and HPV-negative groups) were compared by microbial 16S rDNA sequencing. The protein chip was used to detect the composition and changes of the immune factors in the four groups.

Results

Alpha diversity analysis demonstrated that the diversity of the vaginal microbiota was increased as the disease develops. Among those bacteria abundant in the vaginal microbiota, Lactobacillus, Prevotella, and Gardnerella dominate at the genus level of vaginal flora. Compared with the HPV-negative group, the differentially dominant bacteria, such as Prevotella, Ralstonia, Gardnerella and Sneathia, are enriched in the cervical cancer group. Likewise, Gardnerella, Prevotella, and Sneathia are more in the HPV-positive CIN group, while Gardnerella and Prevotella in the HPV-positive non-CIN group, respectively. In contrast, Lactobacillus and Atopobium are dominant in the HPV-negative group (LDA>4log10). The concentration of inflammatory immune factors IP-10 and VEGF-A were increased in the cervical cancer group (P < 0.05), compared with other groups.

Conclusion

The occurrence of cervical cancer is related to an increase of vaginal microbiota diversity and up-regulation of inflammatory immune factor proteins. The abundance of Lactobacillus was decreased while the one of Prevotella and Gardnerella were increased in the cervical cancer group, compared with other three groups. Moreover, the IP-10 and VEGF-A were also increased in the cervical cancer group. Thus, evaluation of changes in the vaginal microbiota and these two immune factor levels might be a potential non-invasive and simple method to predict cervical cancer. Furthermore, it is significant to adjust and restore the balance of vaginal microbiota and maintain normal immune function in preventing and treating cervical cancer.

Lactobacillus gasseri LGV03 isolated from the cervico-vagina of HPV-cleared women modulates epithelial innate immune responses and suppresses the growth of HPV-positive human cervical cancer cells

Persistent human papillomavirus (HPV) infections is necessary for the development of cervical cancers. An increasing number of retrospective studies have found the depletion of Lactobacillus microbiota in the cervico-vagina facilitate HPV infection and might be involved in viral persistence and cancer development. However, there have been no reports confirming the immunomodulatory effects of Lactobacillus microbiota isolated from cervico-vaginal samples of HPV clearance in women. Using cervico-vaginal samples from HPV persistent infection and clearance in women, this study investigated the local immune properties in cervical mucosa. As expected, type I interferons, such as IFN-α and IFN-β, and TLR3 globally downregulated in HPV+ persistence group. Luminex cytokine/chemokine panel analysis revealed that L. jannaschii LJV03, L. vaginalis LVV03, L. reuteri LRV03, and L. gasseri LGV03 isolated from cervicovaginal samples of HPV clearance in women altered the host's epithelial immune response, particularly L. gasseri LGV03. Furthermore, L. gasseri LGV03 enhanced the poly (I:C)-induced production of IFN by modulating the IRF3 pathway and attenuating poly (I:C)-induced production of proinflammatory mediators by regulating the NF-κB pathway in Ect1/E6E7 cells, indicating that L. gasseri LGV03 keeps the innate system alert to potential pathogens and reduces the inflammatory effects during persistent pathogen infection. L. gasseri LGV03 also markedly inhibited the proliferation of Ect1/E6E7 cells in a zebrafish xenograft model, which may be attributed to an increased immune response mediated by L. gasseri LGV03.

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.

Microbiome analysis of Brazilian women cervix reveals specific bacterial abundance correlation to RIG-like receptor gene expression

The relationship among microbiome, immunity and cervical cancer has been targeted by several studies, yet many questions remain unanswered. We characterized herein the virome and bacteriome from cervical samples and correlated these findings with innate immunity gene expression in a Brazilian convenience sample of HPV-infected (HPV+) and uninfected (HPV-) women. For this purpose, innate immune gene expression data were correlated to metagenomic information. Correlation analysis showed that interferon (IFN) is able to differentially modulate pattern recognition receptors (PRRs) expression based on HPV status. Virome analysis indicated that HPV infection correlates to the presence of Anellovirus (AV) and seven complete HPV genomes were assembled. Bacteriome results unveiled that vaginal community state types (CST) distribution was independent of HPV or AV status, although bacterial phyla distribution differed between groups. Furthermore, TLR3 and IFNαR2 levels were higher in the Lactobacillus no iners-dominated mucosa and we detected correlations among RIG-like receptors (RLR) associated genes and abundance of specific anaerobic bacteria. Collectively, our data show an intriguing connection between HPV and AV infections that could foster cervical cancer development. Besides that, TLR3 and IFNαR2 seem to create a protective milieu in healthy cervical mucosa (L. no iners-dominated), and RLRs, known to recognize viral RNA, were correlated to anaerobic bacteria suggesting that they might be related to dysbiosis.

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.

Unraveling the Dysbiosis of Vaginal Microbiome to Understand Cervical Cancer Disease Etiology-An Explainable AI Approach

Microbial Dysbiosis is associated with the etiology and pathogenesis of diseases. The studies on the vaginal microbiome in cervical cancer are essential to discern the cause and effect of the condition. The present study characterizes the microbial pathogenesis involved in developing cervical cancer. Relative species abundance assessment identified Firmicutes, Actinobacteria, and Proteobacteria dominating the phylum level. A significant increase in Lactobacillus iners and Prevotella timonensis at the species level revealed its pathogenic influence on cervical cancer progression. The diversity, richness, and dominance analysis divulges a substantial decline in cervical cancer compared to control samples. The β diversity index proves the homogeneity in the subgroups' microbial composition. The association between enriched Lactobacillus iners at the species level, Lactobacillus, Pseudomonas, and Enterococcus genera with cervical cancer is identified by Linear discriminant analysis Effect Size (LEfSe) prediction. The functional enrichment corroborates the microbial disease association with pathogenic infections such as aerobic vaginitis, bacterial vaginosis, and chlamydia. The dataset is trained and validated with repeated k-fold cross-validation technique using a random forest algorithm to determine the discriminative pattern from the samples. SHapley Additive exPlanations (SHAP), a game theoretic approach, is employed to analyze the results predicted by the model. Interestingly, SHAP identified that the increase in Ralstonia has a higher probability of predicting the sample as cervical cancer. New evidential microbiomes identified in the experiment confirm the presence of pathogenic microbiomes in cervical cancer vaginal samples and their mutuality with microbial imbalance.

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.

Human Papilloma Virus: An Unraveled Enigma of Universal Burden of Malignancies

HPV, or Human Papilloma Virus, has been the primary causative agent of genital warts and cervical cancer worldwide. It is a sexually transmitted infection mainly affecting women of reproductive age group, also infecting men and high-risk group individuals globally, resulting in high mortality. In recent years, HPV has also been found to be the major culprit behind anogenital cancers in both gender and oropharyngeal and colorectal cancers. Few studies have reported the incidence of HPV in breast cancers as well. For a few decades, the burden of HPV-associated malignancies has been increasing at an alarming rate due to a lack of adequate awareness, famine vaccine coverage and hesitancy. The effectiveness of currently available vaccines has been limited to prophylactic efficacy and does not prevent malignancies associated with post-exposure persistent infection. This review focuses on the current burden of HPV-associated malignancies, their causes and strategies to combat the growing prevalence of the cancers. With the advent of new technologies associated with treatment pertaining to therapeutic interventions and employing effective vaccine coverage, the burden of this disease may be reduced in the population.

The European Society of Gynaecological Oncology (ESGO), the International Society for the Study of Vulvovaginal Disease (ISSVD), the European College for the Study of Vulval Disease (ECSVD), and the European Federation for Colposcopy (EFC) consensus statement on the management of vaginal intraepithelial neoplasia

The European Society of Gynaecological Oncology (ESGO), the International Society for the Study of Vulvovaginal Disease (ISSVD), the European College for the Study of Vulval Disease (ECSVD), and the European Federation for Colposcopy (EFC) developed consensus statements on pre-invasive vulvar lesions in order to improve the quality of care for patients with vaginal intraepithelial neoplasia (VaIN). The management of VaIN varies according to the grade of the lesion: VaIN 1 (low grade vaginal squamous intraepithelial lesions (SIL)) can be subjected to follow-up, while VaIN 2-3 (high-grade vaginal SIL) should be treated. Treatment needs individualization according to the patient's characteristics, disease extension and previous therapeutic procedures. Surgical excision is the mainstay of treatment and should be performed if invasion cannot be excluded. Total vaginectomy is used only in highly selected cases of extensive and persistent disease. Carbon dioxide (CO2) laser may be used as both an ablation method and an excisional one. Reported cure rates after laser excision and laser ablation are similar. Topical agents are useful for persistent, multifocal lesions or for patients who cannot undergo surgical treatment. Imiquimod was associated with the lowest recurrence rate, highest human papillomavirus (HPV) clearance, and can be considered the best topical approach. Trichloroacetic acid and 5-fluorouracil are historical options and should be discouraged. For VaIN after hysterectomy for cervical intraepithelial neoplasia (CIN) 3, laser vaporization and topical agents are not the best options, since they cannot reach epithelium buried in the vaginal scar. In these cases surgical options are preferable. Brachytherapy has a high overall success rate but due to late side effects should be reserved for poor surgical candidates, having multifocal disease, and with failed prior treatments. VaIN tends to recur and ensuring patient adherence to close follow-up visits is of the utmost importance. The first evaluation should be performed at 6 months with cytology and an HPV test during 2 years and annually thereafter. The implementation of vaccination against HPV infection is expected to contribute to the prevention of VaIN and thus cancer of the vagina. The effects of treatment can have an impact on quality of life and result in psychological and psychosexual issues which should be addressed. Patients with VaIN need clear and up-to-date information on a range of treatment options including risks and benefits, as well as the need for follow-up and the risk of recurrence.

The European Society of Gynaecological Oncology (ESGO), the International Society for the Study of Vulvovaginal Disease (ISSVD), the European College for the Study of Vulval Disease (ECSVD), and the European Federation for Colposcopy (EFC) Consensus Statement on the Management of Vaginal Intraepithelial Neoplasia

ABSTRACT

The European Society of Gynaecological Oncology (ESGO), the International Society for the Study of Vulvovaginal Disease (ISSVD), the European College for the Study of Vulval Disease (ECSVD), and the European Federation for Colposcopy (EFC) developed consensus statements on pre-invasive vulvar lesions in order to improve the quality of care for patients with vaginal intraepithelial neoplasia (VaIN). The management of VaIN varies according to the grade of the lesion: VaIN 1 (low grade vaginal squamous intraepithelial lesions (SIL)) can be subjected to follow-up, while VaIN 2-3 (high-grade vaginal SIL) should be treated. Treatment needs individualization according to the patient's characteristics, disease extension and previous therapeutic procedures. Surgical excision is the mainstay of treatment and should be performed if invasion cannot be excluded. Total vaginectomy is used only in highly selected cases of extensive and persistent disease. Carbon dioxide (CO2) laser may be used as both an ablation method and an excisional one. Reported cure rates after laser excision and laser ablation are similar. Topical agents are useful for persistent, multifocal lesions or for patients who cannot undergo surgical treatment. Imiquimod was associated with the lowest recurrence rate, highest human papillomavirus (HPV) clearance, and can be considered the best topical approach. Trichloroacetic acid and 5-fluorouracil are historical options and should be discouraged. For VaIN after hysterectomy for cervical intraepithelial neoplasia (CIN) 3, laser vaporization and topical agents are not the best options, since they cannot reach epithelium buried in the vaginal scar. In these cases surgical options are preferable. Brachytherapy has a high overall success rate but due to late side effects should be reserved for poor surgical candidates, having multifocal disease, and with failed prior treatments. VaIN tends to recur and ensuring patient adherence to close follow-up visits is of the utmost importance. The first evaluation should be performed at 6 months with cytology and an HPV test during 2 years and annually thereafter. The implementation of vaccination against HPV infection is expected to contribute to the prevention of VaIN and thus cancer of the vagina. The effects of treatment can have an impact on quality of life and result in psychological and psychosexual issues which should be addressed. Patients with VaIN need clear and up-to-date information on a range of treatment options including risks and benefits, as well as the need for follow-up and the risk of recurrence.

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.

Potential Role of Vaginal Microbiota in Ovarian Cancer Carcinogenesis, Progression and Treatment

Ovarian cancer represents one of the most challenging gynecologic cancers which still has numerous unknowns on the underlying pathogenesis. In addition to the verified contributors such as genomic predisposition and medical history in the carcinogenesis, emerging evidence points out the potential role of vaginal microbiota in ovarian cancer. Recent studies have underlined the presence of vaginal microbial dysbiosis in cancer cases. Increasing research also indicates the potential correlations between vaginal microbes and cancer carcinogenesis, progression and treatment. Currently, compared with other gynecologic cancers, reports on the roles of vaginal microbiota in ovarian cancer remain scarce and fragmentary. Therefore, in this review, we summarize the roles of vaginal microbiota in various gynecologic diseases, particularly focusing on the potential mechanisms and possible applications of vaginal microbiota in ovarian cancer, giving insight into the involvement of vaginal microbiota in gynecologic cancer treatment.

Vaginal Microbiota and Pregnancy Outcomes of Patients with Conization Histories

Background: One of the major risks of preterm birth is a history of conization. However, the risk of infection due to this procedure is still not well known. Using next-generation sequencing, we aimed to reveal the influence of conization on vaginal microbiota in the following pregnancy, and their relationship between spontaneous preterm birth (sPTB). Methods: We conducted a prospective cohort study including 133 pregnant patients, of whom 25 had conization histories and 108 did not. Vaginal microbiome samples were collected using swabs by an obstetrician upon inclusion in the first trimester and during delivery. V1-V2 of the 16S rRNA gene were amplified and analyzed to identify the bacteria. Results: The conization group had a significantly lower delivery week (34 weeks vs. 36 weeks, p = 0.003) and higher sPTB rate (64% vs. 8.3%, p ≤ 0.001) than the control group. In the conization group, alpha (Chao 1, p = 0.02; phylogenetic diversity whole tree, p = 0.04) and beta diversity (permutational multivariate analysis of variance test, p = 0.04) of the vaginal microbiota was significantly higher during delivery in patients who delivered preterm than in those who delivered term. Community-state type IV in the first trimester was significantly associated with sPTB (overall odds ratio 3.80, 95% confidence interval 1.33-10.8, p = 0.01). Conclusions: Conization is a risk factor for sPTB. Increased risk of sPTB in patients after conization may belong to the vulnerable defense mechanism, due to the shortened cervix and decreased cervical mucus.

Analysis of the related factors of atypical squamous cells of undetermined significance (ASC-US) in cervical cytology of post-menopausal women

Introduction

Atrophy of the reproductive tract mucosa caused by the decrease of estrogen may increase the detection rate of ASC-US in cervical cytology of post-menopausal women. In addition, other pathogenic infections and inflammation can change the cellular morphology and increase the detection rate of ASC-US. However, further studies are needed to elucidate whether the high detection rate of ASC-US in post-menopausal women leads to the high referral rate of colposcopy.

Methods

This retrospective study was conducted to document ASC-US in cervical cytology reports at the Department of Cytology at Gynecology and Obstetrics, Tianjin Medical University General Hospital between January 2006 and February 2021. We then analyzed 2,462 reports of women with ASC-US at the Cervical Lesions Department. A total of 499 patients with ASC-US and 151 cytology with NILM participants underwent vaginal microecology tests.

Results

The average reporting rate of ASC-US in cytology was 5.7%. The detection rate of ASC-US in women aged > 50 years (7.0%) was significantly higher than that in women aged ≤50 years (5.0%) (P<0.05). The CIN2+ detection rate was significantly lower in the post- (12.6%) than in pre-menopausal (20.5%) patients with ASC-US (P <0.05). The prevalence of abnormal reporting rate of vaginal microecology was significantly lower in the pre-menopausal group (56.2%) than that in the post-menopausal group (82.9%) (P<0.05). The prevalence of bacterial vaginosis (BV) (19.60%) was relatively high in the pre-menopausal group, but the abundance of bacteria-inhibiting flora (40.79%) was mainly an abnormality in the post-menopausal group. The vaginal microecological abnormality rate of the women with HR-HPV (-) of ASC-US was 66.22%, which was significantly higher than that of the HR-HPV (-) and the NILM group (52.32%; P<0.05).

Discussion

The detection rate of ASC-US in women aged > 50 years was higher than that ≤50 years, but the detection rate of CIN2+ was lower in the post-menopausal women with ASC-US. However, vaginal microecological abnormalities may increase the false-positive diagnosis rate of ASC-US. The vaginal microecological abnormalities of the menopausal women with ASC-US are mainly attributed to infectious diseases such as BV, and it mainly occurs in the post-menopausal women was bacteria-inhibiting flora. Therefore, to avoid the high referral rate for colposcopy, more attention should be paid to the detection of vaginal microecology.

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.

Inhibitory effect and mechanism of Lactobacillus crispatus on cervical precancerous cells Ect1/E6E7 and screening of early warning factors

OBJECTIVE

To study the potential mechanism of Lactobacillus crispatus inhibiting cervical squamous intraepithelial lesion (SIL) and screen the early warning factors of SIL.

METHODS

The effects of Lactobacillus crispatus on the proliferation, apoptosis, cross pore migration and invasion and cytokines of cervical precancerous cells Ect1/E6E7 were detected respectively. The effect of Lactobacillus crispatus on the expression of differential proteins screened in Ect1/E6E7 cells were detected by Western blot.

RESULTS

Lactobacillus crispatus significantly inhibited the proliferation, induced apoptosis and inhibited cell migration of Ect1/E6E7 cells in a time-dependent manner (P < 0.05), but had no significant effect on cell invasion. Lactobacillus crispatus significantly promoted the secretion of Th1 cytokines and inhibited the secretion of Th2 cytokines by Ect1/E6E7 cells (P < 0.05). In addition, compared with SiHa cells in the control group, the expression of differential proteins PCNA, ATM, LIG1 and HMGB1 in Ect1/E6E7cells decreased significantly, while the expression of TDG and OGG1 proteins increased significantly (P < 0.05). ABCG2 protein in Ect1/E6E7 cells was slightly higher than that in SiHa cells, but the difference was not statistically significant. What is interesting is that Lactobacillus crispatus significantly inhibited the expression of ABCG2, PCNA, ATM, LIG1, OGG1 and HMGB1 proteins in Ect1/E6E7 cells, and promoted the expression of TDG protein.

CONCLUSIONS

Lactobacillus crispatus may inhibit the function of Ect1/E6E7 cells through multiple pathways and exert the potential to reverse the progression of SIL.

The microbiota as a modulator of mucosal inflammation and HIV/HPV pathogenesis: From association to causation

Although the microbiota has largely been associated with the pathogenesis of viral infections, most studies using omics techniques are correlational and hypothesis-generating. The mechanisms affecting the immune responses to viral infections are still being fully understood. Here we focus on the two most important sexually transmitted persistent viruses, HPV and HIV. Sophisticated omics techniques are boosting our ability to understand microbiota-pathogen-host interactions from a functional perspective by surveying the host and bacterial protein and metabolite production using systems biology approaches. However, while these strategies have allowed describing interaction networks to identify potential novel microbiota-associated biomarkers or therapeutic targets to prevent or treat infectious diseases, the analyses are typically based on highly dimensional datasets -thousands of features in small cohorts of patients-. As a result, we are far from getting to their clinical use. Here we provide a broad overview of how the microbiota influences the immune responses to HIV and HPV disease. Furthermore, we highlight experimental approaches to understand better the microbiota-host-virus interactions that might increase our potential to identify biomarkers and therapeutic agents with clinical applications.

The Role of Intratumor Microbiomes in Cervical Cancer Metastasis

BACKGROUND

Intratumor microbiomes can influence tumorigenesis and progression. The relationship between intratumor microbiomes and cervical cancer metastasis, however, remains unclear.

METHODS

We examined 294 cervical cancer samples together with information on microbial expression, identified metastasis-associated microbiomes, and used machine learning methods to validate their predictive ability on tumor metastasis. The tumors were subsequently typed based on differences in microbial expression. Differentially expressed genes in different tumor types were combined to construct a tumor-prognostic risk score model and a multiparameter nomogram model. In addition, we performed a functional enrichment analysis of differentially expressed genes to infer the mechanism of action between microbiomes and tumor cells.

RESULTS

Based on the 15 differentially expressed microbiomes, machine learning models were able to correctly predict the risk of cervical cancer metastasis. In addition, both the risk score and the nomogram model accurately predicted tumor prognosis. Differences in the expression of endogenous genes in tumors can influence the distribution of the intracellular microbiomes.

CONCLUSIONS

Intratumoral microbiomes in cervical cancer are associated with tumor metastasis and influence disease prognosis. A change in gene expression within tumor cells is responsible for differences in the microbial populations within the tumor.

Microbiota unbalance in relation to high-risk human papillomavirus cervical infection

OBJECTIVES

To assess vaginal dysfunction using basic vaginal states and the presence of lactobacillary microbiota in patients with human papillomavirus (HPV) infection with no squamous intra-epithelial lesions (SIL), with low-grade squamous intra-epithelial lesions (L-SIL), and with high-grade squamous intra-epithelial lesions (H-SIL) or squamous cell carcinoma compared with a control group (HPV-negative); to establish the prevalence of bacterial vaginosis, candidiasis, and trichomoniasis in the different age groups; and to characterize the species of lactobacilli according to the type of lesion.

METHODS

A cross-sectional study was carried out of patients who underwent clinical examination and collection of vaginal fornixes to study basic vaginal states and culture. Species identification of lactobacilli was performed by mass spectrometry. The results were analyzed using the χ² and Fisher's tests; p<0.05 was considered significant. High-risk viral types were determined using a multiplex real-time polymerase chain reaction test.

RESULTS

A total of 741 patients were analyzed and divided into three age groups: Group 1 aged 18-24 years (n=138), Group 2 aged 25-50 years (n=456), and Group 3 aged >50 years (n=147). All groups were further divided into an HPV-negative (control) group and an HPV-positive group without lesions, with L-SIL, or with H-SIL/squamous cell carcinoma. The prevalence of unbalanced basic vaginal states in patients with H-SIL/squamous cell carcinoma was 72.7% (p=0.03) in Group 1, 53.1% (p=0.05) in Group 2, and no cases of unbalance were detected in Group 3. The prevalence of bacterial vaginosis in women with H-SIL/squamous cell carcinoma in Group 1 was 54.5% and in Group 2 was 43.7%. Patients with H-SIL/squamous cell carcinoma had a prevalence of 21.4% of Lactobacillus crispatus, 42.9% of L. jensenii, and 14.3% of L. iners.

CONCLUSIONS

A greater unbalance of vaginal microbiota was observed in patients with SIL, especially in those with H-SIL/squamous cell carcinoma. In this group, an increase in L. jensenii and L. iners compared with control was found. L. crispatus had a similar prevalence to the control group. It is important to characterize the lactobacilli species since the unbalance alters the vaginal microenvironment and acts as a co-factor in the persistence of HPV infection.

Roles of vaginal flora in human papillomavirus infection, virus persistence and clearance

Vaginal flora plays a vital role in human papillomavirus (HPV) infection and progression to cancer. To reveal a role of the vaginal flora in HPV persistence and clearance, 90 patients with HPV infection and 45 healthy individuals were enrolled in this study and their vaginal flora were analyzed. Women with HPV infection were treated with Lactobacillus in the vaginal environment as a supplement to interferon therapy. Our results indicated that patients with high risk HPV (Hr-HPV) 16/18 infection had a significantly higher alpha diversity compared with the healthy control (p < 0.01), while there was no significant difference between the non-Hr-HPV16/18 group and the controls (p > 0.05). Patients with multiple HPV infection had insignificantly higher alpha diversity compared with single HPV infection (p > 0.05). The vaginal flora of patients with HPV infection exhibited different compositions when compared to the healthy controls. The dominant bacteria with the highest prevalence in HPV-positive group were Lactobacillus iners (n = 49, 54.44%), and the top 3 dominant bacteria in the HPV-persistent group were Lactobacillus iners (n = 34, 53.13%), Sneathia amnii (n = 9, 14.06%), and Lactobacillus delbrueckii (n = 3, 4.69%). Patients with HPV clearance had significantly lower alpha diversity, and the flora pattern was also different between groups displaying HPV clearance vs. persistence. The patients with persistent HPV infection had significantly higher levels of Bacteroidaceae, Erysipelotrichaceae, Helicobacteraceae, Neisseriaceae, Streptococcaceae (family level), and Fusobacterium, Bacteroides, Neisseria, and Helicobacter (genus level) than patients who had cleared HPV (p < 0.05).

Importance

Our study revealed differences in vaginal flora patterns are associated with HPV persistence and its clearance. Interferon plus probiotics can greatly improve virus clearance in some patients. Distinguishing bacterial features associated with HPV clearance in patients would be helpful for early intervention and reverse persistent infection.

HPV-related cervical diseases: Alteration of vaginal microbiotas and promising potential for diagnosis

Vaginal microbiota is closely associated with women's health, however, the correlation between HPV-related cervical disease (HRCD) and vaginal microbiota is still obscure. In this study, patients with HRCD (n = 98) and healthy controls (n = 58) in Hangzhou were recruited, and their vaginal microbiota were collected and analyzed. The composition of the vaginal microbial community was explored, and a disease classification model was developed by random forest algorithm. The results suggested that the diversity of vaginal microbiota was significantly higher in HRCDs than that in healthy controls (p < 0.05). Firmicutes is the dominant phylum in vaginal microbiota, and Lactobacillus was identified as the most altered genus between two groups (p < 0.01). Kyoto Encyclopedia of Genes and Genomes analysis suggested the difference in vaginal microbial community functions between two groups. Furthermore, we identified 10 biomarkers as the optimal marker sets for the random forest model and found a higher probability of disease values in HRCD group in discovery cohort (p < 0.0001), with an area under the receiver operating characteristic curve reaching 89.7% (95% confidence interval: 78.3%-100%). We further validated the model in both validation and independent diagnosis cohorts, confirming its accuracy in the prediction of HRCD. In conclusion, this study revealed the community composition of vaginal microbiota in HRCDs and successfully constructed a diagnostic model for HRCD.

The Microbiome's Influence on Head and Neck Cancers

PURPOSE OF REVIEW

Head and neck tumors (HNC) rank sixth among cancers worldwide. Due to their late diagnosis and poor prognosis, they are a clinical challenge. However, recent years have seen a dynamic development of science on the microbiome. The aim of the study is to discuss the role of the microbiome in HNC, the impact of the microbiome on oncogenesis, the course of the disease, as well as on treatment, and its toxicity.

RECENT FINDINGS

The microbiome's influence on oncogenesis, the course of the disease, and the effectiveness of oncological treatment have been confirmed in cancers of the colon, pancreas, lungs, and prostate. There is no solid literature on HNC. Many studies indicate disruption of the oral microbiome and periodontal disease as potential cancer risk factors. Disruption of the microbiome increases radiotherapy's toxicity, intensifying radiation reactions. The microbiome plays an important role in cancer. It is a new target in research into new therapies. It may also be a prognostic marker of cancer development. Changes in the composition of the microbiome modulate the effectiveness of oncological treatment. More research is needed on the microbiome and its effects on HNC.

Altered vaginal eukaryotic virome is associated with different cervical disease status

Viruses are important components of the human body. Growing evidence suggests that they are engaged in the physiology and disease status of the host. Even though the vaginal microbiome is involved in human papillomavirus (HPV) infection and cervical cancer (CC) progression, little is known about the role of the vaginal virome. In this pilot exploratory study, using unbiased viral metagenomics, we aim to investigate the vaginal eukaryotic virome in women with different levels of cervical lesions, and examine their associations with different cervical disease status. An altered eukaryotic virome was observed in women with different levels of lesions and Lactobacillus profiles. Anelloviruses and papillomaviruses are the most commonly detected eukaryotic viruses of the vaginal virome. Higher abundance and richness of anelloviruses and papillomaviruses were associated with low-grade squamous intraepithelial lesion (LSIL) and CC. Besides, higher anellovirus abundance was also associated with lactobacillus-depleted microbiome profiles and bacterial community state (CST) type IV. Furthermore, increased correlations between Anelloviridae and Papillomaviridae occurred in the women with increased cervical disease severity level from LSIL to CC. These data suggest underlying interactions between different microbes as well as the host physiology. Higher abundance and diversity of both anelloviruses and papillomaviruses shared by LSIL and CC suggest that anellovirus may be used as a potential adjunct biomarker to predict the risk of HPV persistent infection and/or CC. Future studies need to focus on the clinical relevance of anellovirus abundance with cervical disease status, and the evaluation of their potential as a new adjunct biomarker for the prediction and prognoses of CC.

Roles of the Microbiota of the Female Reproductive Tract in Gynecological and Reproductive Health

The microbiome of the female reproductive tract defies the convention that high biodiversity is a hallmark of an optimal ecosystem. Although not universally true, a homogeneous vaginal microbiome composed of species of Lactobacillus is generally associated with health, whereas vaginal microbiomes consisting of other taxa are generally associated with dysbiosis and a higher risk of disease. The past decade has seen a rapid advancement in our understanding of these unique biosystems. Of particular interest, substantial effort has been devoted to deciphering how members of the microbiome of the female reproductive tract impact pregnancy, with a focus on adverse outcomes, including but not limited to preterm birth. Herein, we review recent research efforts that are revealing the mechanisms by which these microorganisms of the female reproductive tract influence gynecologic and reproductive health of the female reproductive tract.

The diversity of vaginal microbiome in women infected with single HPV and multiple genotype HPV infections in China

Introduction

The human papillomavirus (HPV) is the leading cause of cervical cancer globally. However, its microbial composition and association with the types of HPV infection remain elusive.

Methods

This study was designed to characterize the vaginal microbiota of 53 HPV-infected and 16 normal women (control group) by using high-throughput sequencing with the Illumina platform.

Results

In this study, the five leading phyla were Firmicutes (73.9%), Actinobacteriota (12.8%), Proteobacteria (6.2%), Fusobacteria (3.5%), and Bacteroidota (3.1%). We found that single HPV genotype-positive women had higher α-microbial diversity compared with HPV-negative and multiple HPV-positive women. In women with a single HPV genotype infection, the HPV-16 infection had significantly higher α-diversity than other genotype infections. In multiple HPV genotype-positive women, the highest α-diversity was found in women positive for HR-HR HPV genotype infection, compared with other infections. Furthermore, in single- and multiple-genotype infections, the abundance of s_unclassified_g_Lactobacillus decreased whereas the abundance of s_Gardnerella_vaginalis increased compared with control. Additionally, s_unclassified_f_Rhizobiaceae and s_sneathia_sanguinegens were only found in HPV-infected women.

Conclusion

This study showed that the type of HPV infection was associated with the composition of the vaginal microbiota. Further studies on HPV genotypes and vaginal microbiota are necessary to uncover more mysteries of their association and provide a promising therapeutic target as well as low-cost future therapeutic strategies.

Effect of vaginal flora on clinical outcome of frozen embryo transfer

Objective

Vaginal microbiota imbalance is a high risk factor for premature birth, and is closely related to female pelvic inflammation and sexually transmitted diseases. The effect of vaginal microbiota on the outcome of assisted reproductive technology is still unclear. In this study, the vaginal microbial composition and the pregnancy outcome of frozen embryo transfer (FET) was investigated.

Methods

From October 2020 to December 2021, 275 FET cycles were selected from the center of reproductive medicine in Affiliated Hospital of Nantong University. Vaginal secretions were collected on the day of endometrium transformation, and smears were Gram stained. According to the Nugent score they were divided into three groups, including normal group, mild dysbiosis group and sever dysbiosis group. The clinical outcomes of each group were compared.

Results

In 275 FET cycles, the embryo implantation rate, clinical pregnancy rate and ongoing pregnancy rate in the normal group (66.9%,84.3% and 83.1%) were significantly higher than those in the mild dysbiosis group (45.5%, 57.3% and 49.3%) and in sever dysbiosis group (29.6%, 34.2% and 27%). The difference was statistically significant (P<0.01). When compared the preclinical pregnancy loss rate and the miscarriage rate, the normal group (1.3% and 1.3%) was significantly lower than those in the mild dysbiosis group (20.4% and 14.0%) and the sever dysbiosis group (25.5% and 21.1%). The difference was statistically significant (P<0.01), but there was no significant difference between the mild dysbiosis group and sever dysbiosis group (P>0.05).

Conclusion

Nugent score is directly related to the clinical outcome of FET. The Lactobacilli-dominant vaginal flora was a favorable factor for the good clinical outcome of FET, while asymptomatic bacterial vaginosis had a negative correlation with the outcome of FET.

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

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

Aerobic Vaginitis Caused by Enterococcus Faecalis - Clinical Features and Treatment

Bckground

Aerobic vaginitis is an imbalance of the vaginal flora and the main characteristic is an abnormal vaginal flora that contains aerobic and intestinal pathogens with varying degrees of vaginal inflammation. The frequency of AV varies from 12% to 23.7% in symptomatic women who are not pregnant and 4 to 8% during pregnancy and has an increased risk for sexually transmitted diseases (STI). The causative agents of AV are: Enterococcus faecalis (E. faecalis), Esherichia coli, group B streptococcus and Staphylococcus aureus.

Objective

The aim of this review was to present the most important features of aerobic vaginitis regarding description of this frequent clinical problems within population in Bosnia and Herzegovina and also worlfwide.

Methods

Author analized aerobic vaginitis based on scientific literature by searching published papers in important indexed databases.

Results and Discussion

The most frequently isolated AV pathogen is E. faecalis in about 31%. New works indicate the presence of the HPV 16 gene and genome in E. faecalis in the biopsied material of cervical cancer, as well as the ability that HPV 16 genes can be translated and transcribed in these bacteria, and that the HPV gene can form viral particles in these bacteria leads to certain connection that can be a risk factor in the progression of cervical lesions to cancer. A decrease in the number of lactobacilli in the vaginal secretion reduces the defense ability and changes the pH value of the vaginal environment, which favors the development of bacterial inflammation. AV positive for E. faecalis leads to a change in the pH value of the vaginal environment above 5, and the increased pH value of the vaginal environment in HPV positive women can be an association for cervical intraepithelial lesion (CIN). A dominant pathogen in AV such as E. faecalis can reduce the protective effect of lactobacilli by causing inflammation, as well as an increase in IL-6, IL-8 and TNF, increasing the risk of HPV 16 infection resulting in CIN and cervical cancer. In cervical cancer research, the presence of genes and genomes (except E1) of human papillomavirus (HPV) type 16 was found in bacteria such as: E. faecalis and Staphylococcus aureus from cervical cancer biopsies. Intensive treatment of AV could be a very important factor in preventing the onset of precancerous lesions and cervical cancer. The recommended treatment of AV includes a combination of therapy such as: antibacterial (antiseptic and antibiotic), hormonal, non-steroidal anti-inflammatory and/or probiotics, which can be prescribed in the form of local or systemic therapy.

Conclusion

There is no generally accepted clinical strategy for the treatment of AV caused by E. faecalis. Most authors suggest that therapy be based on microscopic or microbiological findings using a topical antibiotic for the infectious agent, a topical steroid to reduce inflammation, and estrogen to treat atrophy.

Changes in the Cervical Microbiota of Women with Different High-Risk Human Papillomavirus Loads

The cervical microbiota is essential in female sexual health, and its altered states seem to have a central role in the dynamic of high-risk papillomavirus (hrHPV) infections. This study aimed to evaluate the variation in bacterial communities' compositions according to hrHPV. We collected two samples per woman, with a difference of 12 ± 1 months between them, and performed a follow-up on 66 of these women. The viral load (VL) of the hrHPV was estimated by quantitative PCR (qPCR), then it was normalized (using the HMBS gene as reference) and transformed to the Log₁₀ scale to facilitate the interpretation. The VL was categorized as Negative, without hrHPV copies; Low, less than 10⁰ hrHPV copies; Medium, between 10⁰ to 10² hrHPV copies; and High, >10² hrHPV copies. The microbiota composition was described through the Illumina Novaseq PE250 platform. The diversity analyses revealed changes regarding the hrHPV VL, where women with low VL (<10⁰ hrHPV copies) presented high diversity. The community state type (CST) IV was the most common. However, in women with high VL, a lower association with Lactobacillus depletion was found. Lactobacillus gallinarum and L. iners were the most abundant species in women with high VL, whereas women with low VL had a 6.06 greater probability of exhibiting Lactobacillus dominance. We identified conspicuous differences in the abundance of 78 bacterial genera between women with low and high VL, where 26 were depleted (e.g., Gardnerella) and 52 increased (e.g., Mycoplasma). A multilevel mixed-effects linear regression showed changes in the diversity due to the interaction between the measurement time and the VL, with a decrease in diversity in the second follow-up in women with low VL (Coeff. = 0.47), whereas the women with medium VL displayed an increase in diversity (Coeff. = 0.58). Here, we report for the first time that the cervical microbiota is influenced by the number of copies of hrHPV, where a decrease in the abundance of Lactobacillus, greater diversity, and enrichment of bacterial taxa is relevant in women with low VL.

Cervical Microbiome in Women Infected with HPV16 and High-Risk HPVs

Human papillomavirus type 16 (HPV16) and/or high-risk (Hr-) HPV are the main causes of cervical cancer. Another element that may contribute to the development of cervical cancer is the microbiota. To date, no study has investigated the entire cervical microbiome, which consists of bacteria, fungi, and viruses. In this study, cervical samples with different histopathology (CIN1, CIN2, and CIN3), with or without HPV16 and Hr-HPVs infection, were enrolled. From bacterial community analysis, 115 bacterial species were found and separated into 2 distinct categories based on Lactobacillus abundance: Lactobacilli-dominated (LD) and non-Lactobacilli-dominated (NLD) groups. The LD group had significantly less bacterial diversity than the NLD group. In addition, the variety of bacteria was contingent on the prevalence of HPV infection. Among distinct histological groups, an abundance of L. iners (>60% of total Lactobacillus spp.) was discovered in both groups. A few fungi, e.g., C. albicans, were identified in the fungal community. The viral community analysis revealed that the presence of HPV considerably reduced the diversity of human viruses. Taken together, when we analyzed all our results collectively, we discovered that HPV infection was a significant determinant in the diversity of bacteria and human viruses in the cervix.

Which is the best management for women with normal cervical cytologic findings despite positivity for non-16/18 high risk human papillomaviruses?

Women who test positive for the human papillomavirus (HPV) but have normal cytology constitute the predominant subgroup of patients in the screening population in the post-vaccination era. The distribution of HPV genotypes changed dramatically, which was attributable to an increase in HPV vaccination coverage. These changes have created uncertainty about how to properly manage women with normal cytology, non-HPV16/18 infections, or persistent infections. Current recommendations include retesting and continued surveillance in the absence of HPV16/18 infection. However, these are not always applicable. The ability to implement genotyping or incorporate HPV16/18 with some additional high-risk HPV (HR-HPV) types for triage and management with the aim of identifying type-specific risks in this population could be acceptable. When the next set of guidelines is updated, generating potential triage strategies for detecting high-grade cervical lesions, such as the p16/Ki67 cytology assay and other alternatives that incorporate genotyping with newer tests, should be considered. Current clinical management is shifting to risk-based strategies; however, no specific risk threshold has been established in this population. Importantly, innovative triage testing should be evaluated in combination with primary screening and management. Furthermore, there is an untapped opportunity to coordinate HPV genotyping in combination with colposcopic characteristics to modify risk in this group. Hence, providing a more personalized schedule through the efficient application of risk stratification and improving the detection of pre-cancer and cancer is an option worth exploring.

Vaginal microbiota and HPV clearance: A longitudinal study

Although vaginal microbiota (VM) may interact with human papillomavirus (HPV) infection and clearance, longitudinal data remain very limited. We aimed to investigate the association between VM at baseline and the clearance of high-risk HPV (HR-HPV) infection within 12 months. Cervical swabs were collected at diagnosis from 85 patients with HR-HPV infection and histologically confirmed cervical lesions, including cervicitis, low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion. Microbiome analysis was performed using 16S rRNA gene sequencing. Among the 73 women included in the analyses, HPV clearance was observed in 58.9% of the patients within 12 months. No significant difference was observed between the HPV-cleared and HPV-uncleared groups regarding age, disease stage, HPV subtype, VM community state types, and VM diversity (α and β). Women with the depletion of enterococcus ASV_62 and enrichment in Lactobacillus iners at baseline were less likely to have HPV clearance at month 12. Further analysis revealed a significant negative association between high abundance of L. iners and HPV clearance in patients who received non-operative treatment (OR = 3.94, p = 0.041), but not in those who received operative treatment (OR = 1.86, p = 0.660). Our findings provide new evidence for the potential role of VM in the persistent HR-HPV infections.

Lactobacillus crispatus M247 oral administration: Is it really an effective strategy in the management of papillomavirus-infected women?

BACKGROUND

Recent studies have shown the importance of the microbiota in women's health. Indeed, the persistence of Human Papilloma Virus (HPV)-related lesions in patients with dysbiosis can be the antechamber to cervical cancer. The aim of this study was to evaluate whether long term administration of oral Lactobacillus crispatus can restore eubiosis in women with HPV infections and hence achieve viral clearance.

METHODS

In total, 160 women affected by HPV infections were enrolled at the Department of Gynecological Obstetrics of "San Paolo" Hospital, Italy between February 2021 and February 2022. The women were randomly assigned to two groups, one in treatment with oral Lactobacillus crispatus M247 (group 1, n = 80) versus the control group, that hence only in follow-up (Group 2, n = 80).

RESULTS

After a median follow-up of 12 months (range 10-30 months), the likelihood of resolving HPV-related cytological anomalies was higher in patients in treatment with the long term oral probiotic (group 1) versus the group that perfom only follow-up (group 2) (60.5% vs. 41.3%, p = 0.05). Total HPV clearance was shown in 9.3% of patients undergoing only follow-up compared to 15.3% of patients in the group taking long term oral Lactobacillus crispatus M247 (p = 0.34). However, the percentage of HPV-negative patients, assessed with the HPV-DNA test, documented at the end of the study period was not significantly different from the control group.

CONCLUSIONS

Despite the limitations of our analysis, we found a higher percentage of clearance of PAP-smear abnormalities in patients who took long term oral Lactobacillus crispatus M247 than in the control group. Larger studies are warranted, but we believe that future research should be aimed in this direction. Trial registration This study is retrospectively registered.

Research of cervical microbiota alterations with human papillomavirus infection status and women age in Sanmenxia area of China

Background

Human papillomavirus (HPV) infection is the leading cause of cervical cancer. More and more studies discovered that cervical microbiota (CM) composition correlated with HPV infection and the development of cervical cancer. However, more studies need to be implemented to clarify the complex interaction between microbiota and the mechanism of disease development, especially in a specific area of China.

Materials and methods

In this study, 16S rDNA sequencing was applied on 276 Thin-prep Cytologic Test (TCT) samples of patients from the Sanmenxia area. Systematical analysis of the microbiota structure, diversity, group, and functional differences between different HPV infection groups and age groups, and co-occurrence relationships of the microbiota was carried out.

Results

The major microbiota compositions of all patients include Lactobacillus iners, Escherichia coli, Enterococcus faecalis, and Atopobium vaginae at species level, and Staphylococcus, Lactobacillus, Gardnerella, Bosea, Streptococcus, and Sneathia in genus level. Microbiota diversity was found significantly different between HPV-positive (Chao1 index: 98.8869, p < 0.01), unique-268 infected (infections with one of the HPV genotype 52, 56, or 58, 107.3885, p < 0.01), multi-268 infected (infections with two or more of HPV genotype 52, 56, and 58, 97.5337, p = 0.1012), other1 (94.9619, p < 0.05) groups and HPV-negative group (83.5299). Women older than 60 years old have higher microbiota diversity (108.8851, p < 0.01, n = 255) than younger women (87.0171, n = 21). The abundance of Gardnerella and Atopobium vaginae was significantly higher in the HPV-positive group than in the HPV-negative group, while Burkholderiaceae and Mycoplasma were more abundant in the unique-268 group compared to the negative group. Gamma-proteobacteria and Pseudomonas were found more abundant in older than 60 patients than younger groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Clusters of Orthologous Groups (COG) analysis revealed the effects on metabolism by microbiota that the metabolism of cells, proteins, and genetic information-related pathways significantly differed between HPV-negative and positive groups. In contrast, lipid metabolism, signal transduction, and cell cycle metabolism pathway significantly differed between multi-268 and negative groups.

Conclusion

The HPV infection status and age of women were related to CM’s diversity and function pathways. The complex CM co-occurrent relationships and their mechanism in disease development need to be further investigated.

In-depth insights into cervicovaginal microbial communities and hrHPV infections using high-resolution microbiome profiling

The cervicovaginal microbiome (CVM) correlates with women's cervical health, and variations in its composition are associated with high-risk human papillomavirus (hrHPV) infection outcomes. Cervicovaginal microbes have been grouped into five community state types (CSTs) based on microbial community composition and abundance. However, studying the impact of CSTs in health and disease is challenging because the current sequencing technologies have limited confident discrimination between closely related and yet functionally different bacterial species. Circular probe-based RNA sequencing (ciRNAseq) achieves high-resolution microbiome profiling and therefore provides in-depth and unambiguous knowledge about the composition of the CVM. Based on ciRNAseq profiling of a large cohort of cervical smears (n = 541), we here define subgroups of CSTs I, III, and IV based on intra-CST differences with respect to abundances of Lactobacillus acidophilus (CSTs I-A vs. I-B and CSTs III-A vs. III-B), Lactobacillus iners (CSTs I-A vs. I-B and CSTs III-A vs. III-B), and Megasphaera genomosp type 1 (CSTs IV-A vs. IV-B). Our results further support the existence of subgroups of CST IV-C that are dominant for non-Lactobacillus species and have intermediate microbial diversity. We also show that CST V is associated with uninfected conditions, and CST IV-A associates with hrHPV-induced cervical disease. In conclusion, we characterized new subdivisions of cervicovaginal CSTs, which may further advance our understanding of women's cervical health and hrHPV-related progression to disease.

Increased diversity of a cervical microbiome associates with cervical cancer

The cervical microbiome (CM) is a complex ecosystem that can change in response to gynecological cancers. We aimed to evaluate changes in the CM of patients who underwent chemoradiation (CRT) therapy for locally advanced cervical cancer. Before and after CRT, cervical swab samples were collected from 16 patients with squamous cell carcinoma of the cervix, and 30 healthy women. All samples were subjected to 16s rRNA-Seq analysis. In healthy premenopausal women the CM comprised mostly Lactobacillus (>90%); the CM community in samples from both pre- and postmenopausal pre-treatment cancer patients was heterogeneous, with a low proportion of Lactobacillus in younger cases. On the genus level, 27 and 11 taxa differentiated healthy controls from cancer patients in pre- and postmenopausal age groups, while 31 and 2 genera differentiated pre- and post-radiation samples and pre-radiation and the follow-up samples, respectively. Microbiome diversity was significantly higher in pre-treatment patients than in healthy controls. The results reveal significant alterations in the CM of cervical cancer patients relative to that in healthy controls; these changes were more striking after CRT. However, further research is needed to determine whether alteration of the CM offers new therapeutic options.

Microbiome and Cervical Cancer – A Review

Cervical cancer (CC) contributes to 6%-29% of all cancers in women. In India, 527,624 new cases of CC are added every year. India contributes to ¼ of deaths worldwide to CC it occurs often in women around the age of 30 yrs which is contributed by a specific kind of human papillomavirus causes long-term infection and inflammation (HPV) which result in morphological changes in the cells of cervix the region that connect vagina and uterus. Cervicovaginal microbiome is observed to be highly diverse among patients with CC where there is reduced number of Latobacillus spp that leads to dysbiosis and decrease in pH and eventually colonised by other anaerobic bacteria. The shift in community state types (CST) is highly associated with the Human Papillomavirus infection and its further progression to cervical dysplasia or CIN i.e. ‘Cervical intraepithelial neoplasia’ and malignant tumour of the cervix uteri. The purpose of this research is to figure out if there’s a link between the cervico-vaginal microbiota and gynaecological cancer and the review also focuses whether cervical microbiome signatures can predict the severity of infection leading to development of CC? Probiotics can be used as a potential alternative to balance the dysbiosis of the cervicovaginal environment. Hence the review summarizes the current knowledge and the interaction of different bacterial groups with Human Papilloma Virus infection and development of CC.

Mycobiome Dysbiosis in Women with Intrauterine Adhesions

The vaginal microbiota dysbiosis is closely associated with the development of reproductive diseases. However, the contribution of mycobiome to intrauterine adhesion (IUA) disease remains unknown. Harnessing 16S and ITS2 rDNA sequencing analysis, we investigate both bacterial and fungal microbiota compositions across 174 samples taken from both cervical canal (CC) and middle vagina (MV) sites of IUA patients. Overall, there is no significant difference in microbial diversity between healthy subjects (HS) and IUA patients. However, we observe the IUA-specific bacterial alterations such as increased Dialister and decreased Bifidobacterium and enriched fungal genera like increased Filobasidium and Exophiala. Moreover, site-specific fungal-bacterial correlation networks are discovered in both CC and MV samples of IUA patients. Mechanistic investigation shows that Candida parapsilosis, other than Candida albicans and Candida maltosa, prevents the exacerbation of inflammatory activities and fibrosis, and modulates bacterial microbiota during IUA progression in a rat model of IUA. Our study thus highlights the importance of mycobiota in IUA progression, which may facilitate the development of therapeutic target for IUA prevention. IMPORTANCE Intrauterine adhesion (IUA) often leads to hypomenorrhea, amenorrhea, repeat miscarriages, and infertility. It has been prevalent over the last few decades in up to 13% of women who experience pregnancy termination during the first trimester, and 30% of women undergo dilation and curettage after a late, spontaneous abortion. However, the pathogenesis of IUA remains unclear. Despite reports of microbiota dysbiosis during IUA progression, there is little information on the effect of fungal microbiota on the development of IUA. This study not only enhances our understanding of the mycobiome in IUA patients but also provides potential intervention strategies for prevention of IUA by targeting mycobiome.

Association of Cervical Dysbacteriosis, HPV Oncogene Expression, and Cervical Lesion Progression

As the fourth most common gynecological cancer, cervical cancer has resulted in more than 300,000 deaths worldwide in 2020. The expression of the human papillomavirus (HPV) oncogenes E6 and E7 is significantly involved in the initiation and progression of cervical neoplasia. Additionally, the composition of the vaginal microbiome was also closely associated with the ability of HPV to induce cervical cancer. However, the relationship between the expression of HPV E6/E7 oncogene and the composition of the vaginal microbiome has not been clearly explored. In our present study, to investigate the relationship between the HPV E6/E7 oncogene and vaginal microbiome, cervical swabs from 115 patients were collected, and their vaginal microbiomes were analyzed by using metagenomics sequencing. Along with the progression of cervical lesions, the diversity of cervical flora increased gradually, and the abundance of Lactobacillus decreased. Compared with the HPV group, the prevalence of HPV E6/E7 and oncogene expression level were significantly upregulated in cervical intraepithelial neoplasia (CIN) and cervical cancer (CC) groups. Additionally, a positive correlation between the expression of the HPV oncogene and the genera Sneathia, Salmonella, Leptotrichia, Pseudomonas, and Roseovarius in the HPV group was observed. In the CIN group, the enrichment of the genera Sneathia and Megasphaera was weakly linked with HPV oncogene overexpression. In the CC group, a strong association between the overabundance of the genera Peptostreptococcus and Enterococcus and the high expression of HPV oncogene was also found. The increased diversity of the vaginal microbiota and the decreased Lactobacillus abundance were significantly associated with the severity of cervical disease, and the expression of the HPV oncogene could also be regulated by certain pathogens in different stages of cervical lesions.

IMPORTANCE The main findings of this study were that we clarified the associations of the different bacterial species with the expression of human papillomavirus (HPV) oncogenes at different stages of cervical cancer. Along with the severity of cervical lesions, the abundance of the genus and species of Lactobacillus obviously declined, while the aerobic and anaerobic bacteria, as well as the prevalence and expression of HPV E6/E7 oncogene, were increased dramatically.

HPV and vaginal microecological disorders in infertile women: a cross-sectional study in the Chinese population

BACKGROUND

The purpose of this study was to evaluate the distributions of vaginal microbiome dysbiosis and human papillomavirus (HPV) subtypes in infertile women and explore the correlations of HPV infection and vaginal microbiome dysbiosis with infertility.

METHODS

In total, 1464 women aged 18-50 years were included in this study; 649 participants were included in the infertility group, and 815 participants were included in the normal group. The participants were tested for HPV, and their vaginal microecology was examined. The χ2 test and Spearman regression were used for statistical analysis, and binary logistic regression was performed to identify the risk factors for infertility.

RESULTS

The patients in the infertility group were younger than those in the normal group, and the proportions of bacterial vaginosis and vaginal imbalance in the infertility group were significantly higher than those in the normal group. The incidence proportions of high-risk HPV types in the infertility group were significantly higher than those in the normal group, and the proportions of high-risk subtytes HPV16, HPV39, HV52, HPV56, and HPV68 were significantly higher in the infertility group than in the normal group. However, there were no significant differences in the incidences of low-risk HPV types. The incidence proportions of vaginal flora imbalance and HPV infection in the infertility group were significantly higher than those in the normal group. HPV16, HPV33, HPV51, HPV52and HPV58 infections were independent risk factors for infertility.

CONCLUSIONS

Vaginal microecological imbalance and HPV infection are directly related to infertility, and precautions should be taken.

Vaginal microbiota and personal risk factors associated with HPV status conversion—A new approach to reduce the risk of cervical cancer?

Vaginal microbiota (VMB) is associated with changes in Human papilloma virus (HPV) status, which consequently influences the risk of cervical cancer. This association was often confounded by personal risk factors. This pilot research aimed to explore the relationship between vaginal microbiota, personal risk factors and their interactions with HPV status conversion to identify the vaginal microbiota that was associated with HPV clearance under heterogeneous personal risk factors. A total of 38 women participated by self-collecting a cervicovaginal mucus (CVM) sample that was sent for metagenomics sequencing. Most of the participants also filled in personal risk factors questionnaire through an eHealth platform and authorized the use of their previous HPV genotyping results stored in this eHealth platform. Based on the two HPV results, the participants were grouped into three cohorts, namely HPV negative, HPV persistent infection, and HPV status conversion. The relative abundance of VMB and personal factors were compared among these three cohorts. A correlation investigation was performed between VMB and the significant personal factors to characterize a robustness of the panel for HPV status change using R programming. At baseline, 12 participants were HPV-negative, and 22 were HPV-positive. Within one year, 18 women remained HPV-positive, 12 were HPV-negative and 4 participants showed HPV clearance. The factors in the eHealth questionnaire were systematically evaluated which identified several factors significantly associated with persistent HPV infection, including age, salary, history of reproductive tract infection, and the total number of sexual partners. Concurrent vaginal microbiome samples suggest that a candidate biomarker panel consisting of Lactobacillus gasseri, Streptococcus agalactiae, and Timona prevotella bacteria, which may be associated with HPV clearance. This pilot study indicates a stable HPV status-related vaginal microbe environment. To establish a robust biomarker panel for clinical use, larger cohorts will be recruited into follow-up studies.