Cervical Microbiome and Cytokine Profile at Various Stages of Cervical Cancer: A Pilot Study

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.

Cervicovaginal microbiome, high-risk HPV infection and cervical cancer: Mechanisms and therapeutic potential

The microbiota in the female genital tract is an intricate assembly of diverse aerobic, anaerobic, and microaerophilic microorganisms, which share the space within the reproductive tract and engage in complex interactions. Microbiome dysbiosis may disrupt the symbiotic relationship between the host and microorganisms and play a pivotal role in the pathogenesis of various diseases, including its involvement in the establishment of human papillomavirus (HPV)-associated cervical cancer (CC). Interventions to restore microbiota homeostasis (e.g., probiotics) and bacterial-vector HPV therapeutic vaccines have been reported to be potentially effective in clearing HPV infection and ameliorating cytological abnormalities. In this review, we place emphasis on elucidating the alterations within the cervical-vaginal microbiota as well as the intratumoral microbiota in the context of high-risk HPV (HR-HPV) infection and its subsequent progression to cervical intraepithelial neoplasia/CC. Furthermore, we explore the mechanisms by which these microbial communities exert potential pathogenic or protective effects, including modulating genital inflammation and immune responses, affecting HR-HPV oncogene expression and oncoprotein production, regulating oxidative stress and deoxyribonucleic acid (DNA) damage, and inducing metabolic rewiring. Lastly, we summarize the latest evidence in human trials regarding the efficacy of probiotics, prebiotics and probiotic-vector HPV therapeutic vaccines. This review aims to foster a deeper understanding of the role of the microbiota in HR-HPV infection-related cervix cancer development, and further provide a theoretical basis for the development of preventive and therapeutic strategies based on microbial modulation.

Comparison of Vaginal microbiota in HPV-negative and HPV-positive pregnant women using a culture-based approach

The purpose of this study was to conduct a comparative analysis of the composition of the dominant groups of vaginal microorganisms in healthy pregnant women and pregnant women infected with HPV using a microbiological culture-based method. The MALDI TOF MS method and 16S rRNA gene fragment sequencing were used to identify microorganisms isolated from healthy pregnant women (n=32) and pregnant women infected with HPV (n=24). It was found that vaginal secretion samples from both groups contained bacteria of 4 phyla: Bacillota, Actinomycetota, Pseudomonadota, Bacteroidota, and Ascomycota fungi. The most common microbial community in healthy pregnant women being CST I (p=0.0007), and CST V in pregnant women infected with HPV (p=0.0001). At the genus level, a total of 25 taxa were found in all samples, with Lactobacillus being the dominant genus overall. Escherichia (p<0.0001) and Prevotella (p=0.0001) concentrations were higher in HPV infected patients. When calculating the Pearson correlation coefficient for the phyla, it was found that Bacillota correlated negatively with HPV genotypes 16 and 51 (p≤0.05), but positively with HPV genotype 59 (p≤0.05), just like Actinomycetota (p≤0.05). Bacteroidota correlated positively with HPV genotype 56 (0.001 Collapse

Key Words

• 16s rRNA sequencing
• Community state types
• Human papillomavirus
• Lactobacillus crispatus
• Lactobacillus gasseri
• Lactobacillus iners
• Lactobacillus jensenii
• MALDI TOF MS
• Papillomavirus infection
• a Culture-Based Approach

Collapse

MESH Headings

• Humans
• Female
• Vagina/microbiology
• Vagina/virology
• Pregnancy
• Papillomavirus Infections/virology
• Papillomavirus Infections/microbiology
• Microbiota/genetics
• Adult
• RNA, Ribosomal, 16S/genetics
• Bacteria/classification
• Bacteria/isolation & purification
• Bacteria/genetics
• Papillomaviridae/genetics
• Papillomaviridae/isolation & purification
• Papillomaviridae/classification
• Young Adult
• Pregnancy Complications, Infectious/microbiology
• Pregnancy Complications, Infectious/virology
• Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
• Sequence Analysis, DNA

Collapse

Grants Collapse

Affiliation(s)

Podoprigora Irina Department of Microbiology named after V.S. Kiktenko, Medical Institute, RUDN University named after Patrice Lumumba, Moscow, Russia; Research Institute of Molecular and Cellular Medicine, Medical Institute, RUDN University named after Patrice Lumumba, Moscow, Russia.
Vasina Alena Mytishchi Regional Clinical Hospital, Mytishchi, Russia
Mbarga Manga Joseph Arsene Department of Microbiology named after V.S. Kiktenko, Medical Institute, RUDN University named after Patrice Lumumba, Moscow, Russia; Research Institute of Molecular and Cellular Medicine, Medical Institute, RUDN University named after Patrice Lumumba, Moscow, Russia.
Das Milana Department of Microbiology named after V.S. Kiktenko, Medical Institute, RUDN University named after Patrice Lumumba, Moscow, Russia; Research Institute of Molecular and Cellular Medicine, Medical Institute, RUDN University named after Patrice Lumumba, Moscow, Russia
Pikina Alla Department of Microbiology and Virology, Pirogov Russian National Research Medical University, Russia
Kafarskaya Lyudmila Department of Microbiology and Virology, Pirogov Russian National Research Medical University, Russia
Efimov Boris Department of Microbiology and Virology, Pirogov Russian National Research Medical University, Russia

Collapse

Microbiome-Stealth Regulator of Breast Homeostasis and Cancer Metastasis

Cumulative evidence attests to the essential roles of commensal microbes in the physiology of hosts. Although the microbiome has been a major research subject since the time of Luis Pasteur and William Russell over 140 years ago, recent findings that certain intracellular bacteria contribute to the pathophysiology of healthy vs. diseased tissues have brought the field of the microbiome to a new era of investigation. Particularly, in the field of breast cancer research, breast-tumor-resident bacteria are now deemed to be essential players in tumor initiation and progression. This is a resurrection of Russel's bacterial cause of cancer theory, which was in fact abandoned over 100 years ago. This review will introduce some of the recent findings that exemplify the roles of breast-tumor-resident microbes in breast carcinogenesis and metastasis and provide mechanistic explanations for these phenomena. Such information would be able to justify the utility of breast-tumor-resident microbes as biomarkers for disease progression and therapeutic targets.

Diagnostic and prognostic potential of the intra-tumoral microbiota profile in HPV-independent endocervical adenocarcinoma

Background

Microbial community dynamics have been involved in numerous diseases, including cancer. The diversity of intertumoral microbiota in human papillomavirus independent endocervical adenocarcinoma (HPVI ECA) is not well-characterized.

Objective

Our objective is to delineate the intratumoral microbiota profile in HPVI ECA and investigate its potential influence on oncogenesis.

Methods

We analyzed 45 HPVI ECA cases, comprising 36 gastric-type ECA (GEA) and 9 clear cell carcinomas (CCC). We compared the microbial composition within cancerous and adjacent noncancerous tissue samples using 5R-16S ribosomal DNA sequencing. Further, we investigated the correlation between specific microbes and clinical-pathological metrics as well as patient outcomes.

Results

Our findings demonstrate notable differences in the microbial spectra between cancerous and adjacent noncancerous tissues. Amongst HPVI ECA subtypes, GEAs exhibit more microbial variations compared to CCCs. Using the Random Forest algorithm, we identified two distinct microbial signatures that could act as predictive biomarkers for HPVI ECA and differentiate between GEA and CCC. Varied microbial abundances was related to clinical characteristics of HPVI ECA patients. In addition, high levels of Micrococcus and low levels of unknown genus75 from the Comamonadaceae family were associated with poorer outcomes in HPVI ECA patients. Similarly, an abundance of Microbacterium correlated with reduced overall survival (OS), and a high presence of Streptococcaceae family microbes was linked to reduced recurrence-free survival (RFS) in GEA patients. Intriguingly, a high abundance of Micrococcus was also associated with a worse OS in GEA patients.

Conclusion

The study reveals distinct microbial signatures in HPVI ECA, which have potential as biomarkers for disease prognosis. The correlation between these tumor-associated microbiota features and clinicopathological characteristics underscores the possibility of microbiome-based interventions. Our research provides a foundation for more in-depth studies into the cervical microbiome's role in HPVI ECA.

Nature of the Association between Rheumatoid Arthritis and Cervical Cancer and Its Potential Therapeutic Implications

It is now established that patients with rheumatoid arthritis (RA) have an increased risk of developing cervical cancer (CC) or its precursor, cervical intraepithelial neoplasia (CIN). However, the underlying mechanisms of this association have not been elucidated. RA is characterized by unresolved chronic inflammation. It is suggested that human papillomavirus (HPV) infection in RA patients exacerbates inflammation, increasing the risk of CC. The tumor microenvironment in RA patients with CC is also marked by chronic inflammation, which aggravates the manifestations of both conditions. Gut and vaginal dysbiosis are also considered potential mechanisms that contribute to the chronic inflammation and aggravation of RA and CC manifestations. Numerous clinical and pre-clinical studies have demonstrated the beneficial effects of various nutritional approaches to attenuate chronic inflammation, including polyunsaturated fatty acids and their derivatives, specialized pro-resolving mediators (SPMs), probiotics, prebiotics, and certain diets. We believe that successful resolution of chronic inflammation and correction of dysbiosis, in combination with current anti-RA and anti-CC therapies, is a promising therapeutic approach for RA and CC. This approach could also reduce the risk of CC development in HPV-infected RA patients.

Changes in the gut microbiome of patients with esophageal cancer: A systematic review and meta-analysis based on 16S gene sequencing technology

BACKGROUND

Esophageal cancer (EC) possesses a high degree of malignancy and exhibits poor therapeutic outcomes and prognosis. However, its pathogenesis remains unclear. With the development of macrogene sequencing technology, changes in the intestinal flora have been found to be highly related to the development of EC, although discrepancies and controversies remain in this research area.

MATERIALS AND METHODS

We comprehensively searched the PubMed, EMBASE, and Cochrane's Central Controlled Trials Register and the Scientific Network's database search projects based on systematically reviewed preferred reporting projects and meta-analyses. We used Engauge Digitizer for data extraction and Stata 15.1 for data analysis. In addition, we used the Newcastle-Ottawa Scale for grade grading and forest and funnel plots, sensitivity, and Egger and Beggar tests to evaluate the risk of bias.

RESULTS

This study included 10 studies that assessed stool, tumor, and nontumor esophageal mucosa (gastroscopy and surgical resection) samples from 527 individuals, including 273 patients with EC and 254 healthy control group. We observed remarkable differences in microbial diversity in EC patients compared to healthy controls. The Chao1 index (46.01 vs. 42.67) was significantly increased in EC patients, whereas the Shannon index (14.90 vs. 19.05), ACE (39.24 vs. 58.47), and OTUs(28.93 vs. 70.10) were significantly lower. At the phylum level, the abundance of Bacteroidetes (37.89 vs. 32.77) increased significantly, whereas that of Firmicutes (37.63 vs. 38.72) decreased significantly; the abundance of Clostridium and Verruciformis increased, while that of Actinobacteria and Proteobacteria decreased to varying degrees. The abundance of Bacteroides (8.60 vs. 15.10) and Streptococcaceae (15.08 vs. 27.05) significantly reduced in EC.

CONCLUSIONS

According to our meta-analysis, in patients with EC, the Chao1 index increased, whereas the Shannon and the OTUs decreased. At the phylum level, the abundance of Firmicutes decreased significantly, whereas that of Bacteroidetes and Proteobacteria increased significantly. At the genus/family level, the abundance of Bacteroidaceae, Prevotellaceae and Streptococcaceae decreased significantly, whereas that of Veillonellaceae increased. This meta-analysis identified changes in gut microbiota in patients with EC; however, its conclusions were inconsistent.

Clinical and uterine cervix characteristics of women with Mycoplasma and Ureaplasma in genital discharge

OBJECTIVE

The objective of this study was to assess the clinical and uterine cervix characteristics of patients displaying vaginal discharge with positive results for Mycoplasma sp. and/or Ureaplasma spp.

METHODS

An analytical cross-sectional study involving women aged 18-45 years was conducted. Microbiological assessments included Ureaplasma and Mycoplasma cultures, as well as human papillomavirus hybrid capture using ecto and endocervix swabs. All tests were two-tailed, and significance was set at p<0.05.

RESULTS

Among 324 women, Ureaplasma prevalence was 17.9%, and Mycoplasma prevalence was 3.1%. The Ureaplasma-positive group exhibited a higher frequency of urinary tract infections (39.1 vs. 19%, p=0.002) and human papillomavirus (39.7 vs. 12.8%, p≤0.001) compared with controls. The Mycoplasma-positive group showed a higher frequency of non-contraceptive use compared with controls (66.2 vs. 30.0%, p=0.036). Abnormal colposcopic findings were more prevalent in the Mycoplasma/Ureaplasma-positive group than in controls (positive: 65% vs. control: 35%, p=0.001). Pap smear findings did not differ between the groups.

CONCLUSION

Ureaplasma spp. was associated with urinary tract infections and human papillomavirus, while the presence of Mycoplasma sp. was linked to reduced contraceptive use. When analyzing both pathogens together, a higher frequency of abnormal colposcopic findings was observed, with no difference in cytological findings in the positive group.

An analysis of the vaginal microbiota and cervicovaginal metabolomics in cervical lesions and cervical carcinoma

Background

To explore the role of vaginal microbiota and metabolomics in the progression of cervical dysplasia.

Methods

The patient group consists of female patients with low-grade, high-grade cervical dysplasia, and cervical cancer. Normal cervix samples from health volunteers were used as controls. The metabolic fingerprints of cervicovaginal lavage were analyzed using liquid chromatography-mass spectrometry, while the vaginal microbiota was examined through 16S rRNA sequencing. Bioinformatic analysis was adopted to investigate the interplay between hosts and microbes. The vaginal metabolic and microbiota profiles of 90 female patients with cervical dysplasia and 10 controls were analyzed to discover the biological characteristics underlying the progression of cervical cancer.

Results

We found that Valyl-Glutamate, N, N'-Diacetylbenzidine, and Oxidized glutathione, which were involved in oxidative stress response, were discriminators to distinguish the normal cervix, invasive cervical carcinomas, and CIN3 from others. Cervical carcinoma was characterized by a large variety of vaginal microbes (dominated by non-Lactobacillus communities) compared to the control. These microbes affected amino acid and nucleotide metabolism, producing metabolites with cervical carcinoma and genital inflammation compared to the control group.

Conclusions

This study revealed that cervicovaginal metabolic profiles were determined by cervical cancer, vaginal microbiota, and their interplays. ROS metabolism can be used to discriminate normal cervix, CIN3, and invasive cervical carcinoma.

Vaginal microbiota and gynecological cancers: a complex and evolving relationship

The vagina hosts a community of microorganisms known as the vaginal microbiota. This community is relatively stable and straightforward, with Lactobacillus species being the most dominant members. The vaginal microbiota has various functions that are essential for maintaining human health and balance. For example, it can metabolise dietary nutrients, produce growth factors, communicate with other bacteria, modulate the immune system, and prevent the invasion of harmful pathogens. When the vaginal microbiota is disrupted, it can lead to diseases and infections. The observed disturbance is distinguished by a reduction in the prevalence of Lactobacillus and a concurrent rise in the number of other bacterial species that exhibit a higher tolerance to low oxygen levels. Gynecologic cancers are a group of cancers that affect the female reproductive organs and tissues, such as the ovaries, uterus, cervix, vagina, vulva, and endometrium. These cancers are a major global health problem for women. Understanding the complex interactions between the host and the vaginal microorganisms may provide new insights into the prevention and treatment of gynecologic cancers. This could improve the quality of life and health outcomes for women.

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

Background

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

Methods

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

Results

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

Conclusions

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

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.

Co-evolution of vaginal microbiome and cervical cancer

BACKGROUND

Exploration of adaptive evolutionary changes at the genetic level in vaginal microbial communities during different stages of cervical cancer remains limited. This study aimed to elucidate the mutational profile of the vaginal microbiota throughout the progression of cervical disease and subsequently establish diagnostic models.

METHODS

This study utilized a metagenomic dataset consisting of 151 subjects classified into four categories: invasive cervical cancer (CC) (n = 42), cervical intraepithelial neoplasia (CIN) (n = 43), HPV-infected (HPVi) patients without cervical lesions (n = 34), and healthy controls (n = 32). The analysis focused on changes in microbiome abundance and extracted information on genetic variation. Consequently, comprehensive multimodal microbial signatures associated with CC, encompassing taxonomic alterations, mutation signatures, and enriched metabolic functional pathways, were identified. Diagnostic models for predicting CC were established considering gene characteristics based on single nucleotide variants (SNVs).

RESULTS

In this study, we screened and analyzed the abundances of 18 key microbial strains during CC progression. Additionally, 71,6358 non-redundant mutations were identified, predominantly consisting of SNVs that were further annotated into 25,773 genes. Altered abundances of SNVs and mutation types were observed across the four groups. Specifically, there were 9847 SNVs in the HPV-infected group and 14,892 in the CC group. Furthermore, two distinct mutation signatures corresponding to the benign and malignant groups were identified. The enriched metabolic pathways showed limited similarity with only two overlapping pathways among the four groups. HPVi patients exhibited active nucleotide biosynthesis, whereas patients with CC demonstrated a significantly higher abundance of signaling and cellular-associated protein families. In contrast, healthy controls showed a distinct enrichment in sugar metabolism. Moreover, biomarkers based on microbial SNV abundance displayed stronger diagnostic capability (cc.AUC = 0.87) than the species-level biomarkers (cc.AUC = 0.78). Ultimately, the integration of multimodal biomarkers demonstrated optimal performance for accurately identifying different cervical statuses (cc.AUC = 0.86), with an acceptable performance (AUC = 0.79) in the external testing set.

CONCLUSIONS

The vaginal microbiome exhibits specific SNV evolution in conjunction with the progression of CC, and serves as a specific biomarker for distinguishing between different statuses of cervical disease.

Organoids as an in vitro model to study human tumors and bacteria

Organoids faithfully replicate the morphological structure, physiological functions, stable phenotype of the source tissue. Recent research indicates that bacteria can significantly influence the initiation, advancement, and treatment of tumors. This article provides a comprehensive review of the applications of organoid technology in tumor research, the relationship between bacteria and the genesis and development of tumors, and the exploration of the impact of bacteria on tumors and their applications in research.

Proof of Concept Study: Comparability of Microbiome Diversity in Self- and Physician-Collected HPV-Positive and HPV-Negative Cervicovaginal Samples

Recent studies have revealed the impact of human papillomavirus (HPV) infections on the cervicovaginal microbiome; however, few have explored the utility of self-collected specimens (SCS) for microbiome detection, obtained using standardised methods for HPV testing. Here, we present a proof-of-concept analysis utilising Oxford Nanopore sequencing of the 16S rRNA gene in paired samples collected either by the patient using an Evalyn Brush or collected by a physician using liquid-based cytology (LBC). We found no significant differences in the α-diversity estimates between the SCS and LBC samples. Similarly, when analysing β-diversity, we observed a close grouping of paired samples, indicating that both collection methods detected the same microbiome features. The identification of genera and Lactobacillus species in each sample allowed for their classification into community state types (CSTs). Notably, paired samples had the same CST, while HPV-positive and -negative samples belonged to distinct CSTs. As previously described in other studies, HPV-positive samples exhibited heightened bacterial diversity, reduced Lactobacillus abundance, and an increase in genera like Sneathia or Dialister. Altogether, this study showed comparable results between the SCS and LBC samples, underscoring the potential of self-sampling for analysing the microbiome composition in cervicovaginal samples initially collected for HPV testing in the context of cervical cancer screening.

Risk factors for the development of cervical cancer: analysis of the evidence

Introduction

Cervical cancer (CC) is the fourth most prevalent female cancer globally. Understanding its epidemiology is crucial for devising practical strategies suited to geographic and social contexts to attain the global eradication of CC. Hence, this study examined the latest evidence of risk factors contributing to CC development.

Methods

An independent literature search was conducted on PubMed using MESH terms. The primary sources were meta-analyses published from 2010 to 2023, which detail updated evidence on risk factors associated with CC. Additionally, the quality of the evidence was evaluated using the GRADE system and recommendations were made accordingly.

Results

The main risk factors related to the cause of CC include co-infections with other sexually transmitted infections, genetic markers, cervicovaginal microbiota, nutritional factors, comorbidities that affect the immune response, smoking, and the use of hormonal contraceptives with a quality evidence based on the GRADE scale moderate.

Conclusions

Since the necessary cause for CC is persistent cervicovaginal HPV, all the risk factors implicated in the causality of CC act as non-independent cofactors that increase the risk of CC. Thus, changes in public policies aimed at addressing these risk factors are highly recommended and can substantially decrease the risk of CC.

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.

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.

Relationship between vaginal and oral microbiome in patients of human papillomavirus (HPV) infection and cervical cancer

BACKGROUND

The aim of this study was to assess the microbial variations and biomarkers in the vaginal and oral environments of patients with human papillomavirus (HPV) and cervical cancer (CC) and to develop novel prediction models.

MATERIALS AND METHODS

This study included 164 samples collected from both the vaginal tract and oral subgingival plaque of 82 women. The participants were divided into four distinct groups based on their vaginal and oral samples: the control group (Z/KZ, n = 22), abortion group (AB/KAB, n = 17), HPV-infected group (HP/KHP, n = 21), and cervical cancer group (CC/KCC, n = 22). Microbiota analysis was conducted using full-length 16S rDNA gene sequencing with the PacBio platform.

RESULTS

The vaginal bacterial community in the Z and AB groups exhibited a relatively simple structure predominantly dominated by Lactobacillus. However, CC group shows high abundances of anaerobic bacteria and alpha diversity. Biomarkers such as Bacteroides, Mycoplasma, Bacillus, Dialister, Porphyromonas, Anaerococcus, and Prevotella were identified as indicators of CC. Correlations were established between elevated blood C-reactive protein (CRP) levels and local/systemic inflammation, pregnancy, childbirth, and abortion, which contribute to unevenness in the vaginal microenvironment. The altered microbial diversity in the CC group was confirmed by amino acid metabolism. Oral microbial diversity exhibited an inverse pattern to that of the vaginal microbiome, indicating a unique relationship. The microbial diversity of the KCC group was significantly lower than that of the KZ group, indicating a link between oral health and cancer development. Several microbes, including Fusobacterium, Campylobacter, Capnocytophaga, Veillonella, Streptococcus, Lachnoanaerobaculum, Propionibacterium, Prevotella, Lactobacillus, and Neisseria, were identified as CC biomarkers. Moreover, periodontal pathogens were associated with blood CRP levels and oral hygiene conditions. Elevated oral microbial amino acid metabolism in the CC group was closely linked to the presence of pathogens. Positive correlations indicated a synergistic relationship between vaginal and oral bacteria.

CONCLUSION

HPV infection and CC impact both the vaginal and oral microenvironments, affecting systemic metabolism and the synergy between bacteria. This suggests that the use of oral flora markers is a potential screening tool for the diagnosis of CC.

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.

Sleep duration time and human papillomavirus infection risk: The U-shaped relationship revealed by NHANES data

PURPOSE

This study aims to investigate the relationship between sleep factors (sleep duration time [SDT] and obstructive sleep apnea [OSA]) and human papillomavirus (HPV)/high-risk HPV(HR-HPV) infection, utilizing data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

We conducted a cross-sectional analysis using NHANES data, focusing on SDT and OSA's association with HPV/HR-HPV infection. The primary statistical methods included weighted multivariate linear regression and logistic regression to assess the association between SDT, OSA, and HPV/HR-HPV infection. The study employed restricted cubic splines (RCS) for evaluating potential non-linear relationships between SDT and HPV/HR-HPV infection. Subgroup analyses were conducted. Interaction terms were used to examine the heterogeneity in associations across different subgroups.

RESULTS

The study identified a U-shaped relationship between SDT and HPV infection. Specifically, 7 hours of sleep was associated with the lowest risk of HPV infection. In comparison, SDT less than 7 hours resulted in a 26.3% higher risk of HPV infection (Odds Ratio [OR] = 1.26, 95% Confidence Interval [CI]: 1.029, 1.549), and more than 9 hours of sleep showed a 57.4% increased risk (OR = 1.574, 95% CI: 1.116, 2.220). The relationship between SDT and HR-HPV infection was significant in the first two models, but not in the fully adjusted model. No significant interaction was found between sleep duration and other covariates. There was no association between OSA and HPV/HR-HPV infection.

CONCLUSION

The study underscores the complex relationship between sleep duration and HPV infection risk, suggesting both very short and very long sleep durations may increase HPV infection likelihood. The findings highlight the need for further research to explore the biological mechanisms underpinning this association and to consider broader population groups and more precise sleep assessment methods in future studies.

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

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.

Exploring the Relationship between Ovarian Cancer and Genital Microbiota: A Systematic Review and Meta-Analysis

Ovarian cancer (OC) remains a significant health challenge globally, with high mortality rates despite advancements in treatment. Emerging research suggests a potential link between OC development and genital dysbiosis, implicating alterations in the microbiome composition as a contributing factor. To investigate this correlation, a meta-analysis was conducted following PRISMA and MOOSE guidelines, involving eight studies encompassing 3504 patients. Studies investigating the role of upper and inferior genital tract dysbiosis were included, with particular reference to HPV infection and/or history of pelvic inflammatory disease. The analysis revealed no significant difference in genital dysbiosis prevalence between OC patients and healthy controls. Although previous literature suggests associations between dysbiosis and gynecologic cancers, such as cervical and endometrial cancers, the findings regarding OC are inconclusive. Methodological variations and environmental factors may contribute to these discrepancies, underscoring the need for standardized methodologies and larger-scale studies. Despite the limitations, understanding the microbiome's role in OC development holds promise for informing preventive and therapeutic strategies. A holistic approach to patient care, incorporating microbiome monitoring and personalized interventions, may offer insights into mitigating OC risk and improving treatment outcomes. Further research with robust methodologies is warranted to elucidate the complex interplay between dysbiosis and OC, potentially paving the way for novel preventive and therapeutic approaches.

Deciphering the role of female reproductive tract microbiome in reproductive health: a review

Relevant studies increasingly indicate that female reproductive health is confronted with substantial challenges. Emerging research has revealed that the microbiome interacts with the anatomy, histology, and immunity of the female reproductive tract, which are the cornerstone of maintaining female reproductive health and preventing adverse pregnancy outcomes. Currently, the precise mechanisms underlying their interaction and impact on physiological functions of the reproductive tract remain elusive, constituting a prominent area of investigation within the field of female reproductive tract microecology. From this new perspective, we explore the mechanisms of interactions between the microbiome and the anatomy, histology, and immunity of the female reproductive tract, factors that affect the composition of the microbiome in the female reproductive tract, as well as personalized medicine approaches in managing female reproductive tract health based on the microbiome. This study highlights the pivotal role of the female reproductive tract microbiome in maintaining reproductive health and influencing the occurrence of reproductive tract diseases. These findings support the exploration of innovative approaches for the prevention, monitoring and treatment of female reproductive tract diseases based on the microbiome.

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.

Cancer invasion and anaerobic bacteria: new insights into mechanisms

There is growing evidence that altered microbiota abundance of a range of specific anaerobic bacteria are associated with cancer, including Peptoniphilus spp., Porphyromonas spp., Fusobacterium spp., Fenollaria spp., Prevotella spp., Sneathia spp., Veillonella spp. and Anaerococcus spp. linked to multiple cancer types. In this review we explore these pathogenic associations. The mechanisms by which bacteria are known or predicted to interact with human cells are reviewed and we present an overview of the interlinked mechanisms and hypotheses of how multiple intracellular anaerobic bacterial pathogens may act together to cause host cell and tissue microenvironment changes associated with carcinogenesis and cancer cell invasion. These include combined effects on changes in cell signalling, DNA damage, cellular metabolism and immune evasion. Strategies for early detection and eradication of anaerobic cancer-associated bacterial pathogens that may prevent cancer progression are proposed.

Processing-bias correction with DEBIAS-M improves cross-study generalization of microbiome-based prediction models

Every step in common microbiome profiling protocols has variable efficiency for each microbe. For example, different DNA extraction kits may have different efficiency for Gram-positive and -negative bacteria. These variable efficiencies, combined with technical variation, create strong processing biases, which impede the identification of signals that are reproducible across studies and the development of generalizable and biologically interpretable prediction models. "Batch-correction" methods have been used to alleviate these issues computationally with some success. However, many make strong parametric assumptions which do not necessarily apply to microbiome data or processing biases, or require the use of an outcome variable, which risks overfitting. Lastly and importantly, existing transformations used to correct microbiome data are largely non-interpretable, and could, for example, introduce values to features that were initially mostly zeros. Altogether, processing bias currently compromises our ability to glean robust and generalizable biological insights from microbiome data. Here, we present DEBIAS-M (Domain adaptation with phenotype Estimation and Batch Integration Across Studies of the Microbiome), an interpretable framework for inference and correction of processing bias, which facilitates domain adaptation in microbiome studies. DEBIAS-M learns bias-correction factors for each microbe in each batch that simultaneously minimize batch effects and maximize cross-study associations with phenotypes. Using benchmarks of HIV and colorectal cancer classification from gut microbiome data, and cervical neoplasia prediction from cervical microbiome data, we demonstrate that DEBIAS-M outperforms batch-correction methods commonly used in the field. Notably, we show that the inferred bias-correction factors are stable, interpretable, and strongly associated with specific experimental protocols. Overall, we show that DEBIAS-M allows for better modeling of microbiome data and identification of interpretable signals that are reproducible across studies.

Microbiota changes: the unseen players in cervical cancer progression

Cervical cancer ranks among the most prevalent cancers globally with high-risk human papillomaviruses implicated in nearly 99% of cases. However, hidden players such as changes in the microbiota are now being examined as potential markers in the progression of this disease. Researchers suggest that changes in the vaginal microbiota might correlate with cervical cancer. This review provides a comprehensive look at the microbiota changes linked with the advancement of cervical cancer. It also scrutinizes the databases from past studies on the microbiota during healthy and cancerous stages, drawing connections between prior findings concerning the role of the microbiota in the progression of cervical cancer. Preliminary findings identify Fusobacterium spp., Peptostreptococcus spp., Campylobacter spp., and Haemophilus spp., as potential biomarkers for cervical cancer progression. Alloscardovia spp., Eubacterium spp., and Mycoplasma spp. were identified as potential biomarkers for HPVs (+), while Methylobacterium spp. may be indicative of HPV (-). However, the study's limitations, including potential biases and methodological constraints, underscore the need for further research to validate these findings and delve deeper into the microbiota's role in HPV development. Despite these limitations, the review provides valuable insights into microbiota trends during cervical cancer progression, offering direction for future research. The review summarizes key findings from previous studies on microbiota during healthy and cancerous stages, as well as other conditions such as CIN, SIL, HPV (+), and HPV (-), indicating a promising area for further investigation. The consistent presence of HPV across all reported cervical abnormalities, along with the identification of distinct bacterial genera between cancerous and control samples, suggests a potential link that merits further exploration. In conclusion, a more profound understanding of the microbial landscape could elucidate the pathogenesis of cervical diseases and inform future strategies for diagnosis, prevention, and treatment.

The microbiome and gynecologic cancer: cellular mechanisms and clinical applications

The microbiome plays a vital function in maintaining human health and homeostasis. Each microbiota has unique characteristics, including those of the gastrointestinal and female reproductive tract. Dysbiosis, or alterations to the composition of the microbial communities, impacts the microbiota-host relationship and is linked to diseases, including cancer. In addition, studies have demonstrated that the microbiota can contribute to a pro-carcinogenic state through altered host immunologic response, modulation of cell proliferation, signaling, gene expression, and dysregulated metabolism of nutrients and hormones.In recent years, the microbiota of the gut and female reproductive tracts have been linked to many diseases, including gynecologic cancers. Numerous pre-clinical and clinical studies have demonstrated that specific bacteria or microbial communities may contribute to the development of gynecologic cancers. Further, the microbiota may also impact the toxicity and efficacy of cancer therapies, including chemotherapy, immunotherapy, and radiation therapy in women with gynecologic malignancies. The microbiota is highly dynamic and may be altered through various mechanisms, including diet, exercise, medications, and fecal microbiota transplantation. This review provides an overview of the current literature detailing the relationship between gynecologic cancers and the microbiota of the female reproductive and gastrointestinal tracts, focusing on mechanisms of carcinogenesis and strategies for modulating the microbiota for cancer prevention and treatment. Advancing our understanding of the complex relationship between the microbiota and gynecologic cancer will provide a novel approach for prevention and therapeutic modulation in the future.

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.

The effect of the female genital tract and gut microbiome on reproductive dysfunction

Microorganisms are ubiquitous in the human body; they are present in various areas including the gut, mouth, skin, respiratory tract, and reproductive tract. The interaction between the microbiome and reproductive health has become an increasingly compelling area of study. Disruption of the female genital tract microbiome can significantly impact the metabolism of amino acids, carbohydrates, and lipids, increasing susceptibility to reproductive tract diseases such as vaginitis, chronic endometritis, endometrial polyps, endometriosis, and polycystic ovary syndrome. The gut microbiome, considered an endocrine organ, plays a crucial role in the reproductive endocrine system by interacting with hormones like estrogen and androgens. Imbalances in the gut microbiome composition can lead to various diseases and conditions, including polycystic ovary syndrome, endometriosis, and cancer, although research on their mechanisms remains limited. This review highlights the latest advancements in understanding the female genital tract and gut microbiomes in gynecological diseases. It also explores the potential of microbial communities in the treatment of reproductive diseases. Future research should focus on identifying the molecular mechanisms underlying the association between the microbiome and reproductive diseases to develop new and effective strategies for disease prevention, diagnosis, and treatment related to female reproductive organs.

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.

Alterations in gut and genital microbiota associated with gynecological diseases: a systematic review and meta-analysis

BACKGROUND

Increasing number of studies have demonstrated certain patterns of microbial changes in gynecological diseases; however, the interaction between them remains unclear. To evaluate the consistency or specificity across multiple studies on different gynecological diseases and microbial alterations at different sites of the body (gut and genital tract), we conducted a systematic review and meta-analysis.

METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library up to December 5, 2022(PROSPERO: CRD42023400205). Eligible studies focused on gynecological diseases in adult women, applied next-generation sequencing on microbiome, and reported outcomes including alpha or beta diversity or relative abundance. The random-effects model on standardized mean difference (SMD) was conducted using the inverse-variance method for alpha diversity indices.

RESULTS

Of 3327 unique articles, 87 eligible studies were included. Significant decreases were found in gut microbiome of patients versus controls (observed species SMD=-0.35; 95%CI, -0.62 to -0.09; Shannon index SMD=-0.23; 95%CI, -0.40 to -0.06), whereas significant increases were observed in vaginal microbiome (Chao1 SMD = 1.15; 95%CI, 0.74 to 1.56; Shannon index SMD = 0.51; 95%CI, 0.16 to 0.86). Most studies of different diagnostic categories showed no significant differences in beta diversity. Disease specificity was observed, but almost all the changes were only replicated in three studies, except for the increased Aerococcus in bacterial vaginosis (BV). Patients with major gynecological diseases shared the enrichment of Prevotella and depletion of Lactobacillus, and an overlap in microbes was implied between BV, cervical intraepithelial neoplasia, and cervical cancer.

CONCLUSIONS

These findings demonstrated an association between alterations in gut and genital microbiota and gynecological diseases. The most observed results were shared alterations across diseases rather than disease-specific alterations. Therefore, further investigation is required to identify specific biomarkers for diagnosis and treatment in the future.

Human Papillomavirus Infections and the Role Played by Cervical and Cervico-Vaginal Microbiota-Evidence from Next-Generation Sequencing Studies

This comprehensive review encompasses studies examining changes in the cervical and cervico-vaginal microbiota (CM and CVM) in relation to human papillomavirus (HPV) using next-generation sequencing (NGS) technology. HPV infection remains a prominent global health concern, with a spectrum of manifestations, from benign lesions to life-threatening cervical cancers. The CM and CVM, a unique collection of microorganisms inhabiting the cervix/vagina, has emerged as a critical player in cervical health. Recent research has indicated that disruptions in the CM and CVM, characterized by a decrease in Lactobacillus and the overgrowth of other bacteria, might increase the risk of HPV persistence and the progression of cervical abnormalities. This alteration in the CM or CVM has been linked to a higher likelihood of HPV infection and cervical dysplasia. NGS technology has revolutionized the study of the cervical microbiome, providing insights into microbial diversity, dynamics, and taxonomic classifications. Bacterial 16S rRNA gene sequencing, has proven invaluable in characterizing the cervical microbiome, shedding light on its role in HPV infections and paving the way for more tailored strategies to combat cervical diseases. NGS-based studies offer personalized insights into an individual's cervical microbiome. This knowledge holds promise for the development of novel diagnostic tools, targeted therapies, and preventive interventions for cervix-related conditions, including cervical cancer.

Reconnoitering correlation between human papillomavirus infection-induced vaginal microecological abnormality and squamous intraepithelial lesion (SIL) progression

OBJECTIVE

This study aims to investigate the relationship between abnormal vaginal microecology and human papillomavirus (HPV) infection, as well as the squamous intraepithelial lesions (SIL) progression.

METHODS

A total of 383 patients diagnosed with HPV infection in our hospital between March 2017 and February 2022 were selected as the experimental group. In addition, several volunteers (n = 898) who underwent physical examination during the same period were randomly selected as the control group. Subsequently, we conducted several investigations, such as HPV detection and gene typing, examined vaginal microecological imbalances, and performed cytological examinations to analyze the correlation between microecological changes, different types of HPV infection, and SIL progression.

RESULTS

HPV detection primarily included single and high-risk types of HPV infections. Moreover, significant disparities in the vaginal microecological environment between patients with persistent HPV infection and the control group, as well as patients with low-grade and high-grade SIL (LSIL and HSIL), were observed. The regression analysis revealed a correlation between LSIL and microflora density, diversity, bacteriological vaginosis (BV), vulvovaginal candidiasis (VVC), trichomonas vaginalis (TV), sialidase, as well as Lactobacillus. In addition, we identified an association between HSIL and pH, flora density, diversity, BV, VVC, candida vaginitis (CV), leukocyte esterase, catalase, and Lactobacillus levels.

CONCLUSION

These findings revealed a significant association between abnormal vaginal microecology and both HPV infection and the SIL progression.

Inflammatory cytokines and a diverse cervicovaginal microbiota associate with cervical dysplasia in a cohort of Hispanics living in Puerto Rico

Cervical cancer (CC) is women's fourth most common cancer worldwide. A worrying increase in CC rates in Hispanics suggests that besides Human papillomavirus infections, there may be other cofactors included in the epithelial microenvironment that could play a role in promoting the disease. We hypothesized that the cervical microbiome and the epithelial microenvironment favoring inflammation is conducive to disease progression in a group of Hispanics attending gynecology clinics in Puerto Rico. Few studies have focused on the joint microbiota and cytokine profile response in Hispanics outside the US, especially regarding the development of precancerous lesions. We aimed to investigate the relationship between the cervicovaginal microbiome and inflammation in Hispanic women living in PR while considering cervical dysplasia and HPV genotype risk. Cervical samples collected from 91 participants coming to gynecology clinics in San Juan, underwent 16S rRNA genes (V4 region) profiling, and cytokines were measured using Luminex MAGPIX technology. Cytokines were grouped as inflammatory (IL-1β, TNFα, IFNγ, IL-6), anti-inflammatory (IL- 4, IL-10, TGFβ1), and traffic-associated (IL-8, MIP1a, MCP1, IP10). They were related to microbes via an inflammation scoring index based on the quartile and tercile distribution of the cytokine's concentration. We found significant differences in the diversity and composition of the microbiota according to HPV type according to carcinogenic risk, cervical disease, and cytokine abundance. Community State Types (CSTs) represents a profile of microbial communities observed within the vaginal microbiome ecological niche, and Lactobacillus-depleted CST IV had ~ 90% dominance in participants with high-grade squamous intraepithelial lesions and high-risk HPV. The increasing concentration of pro-inflammatory cytokines was associated with a decrease in L. crispatus. In contrast, dysbiosis-associated bacteria such as Gardnerella, Prevotella, Atopobium concomitantly increased with pro-inflammatory cytokines. Our study highlights that the cervical microbiota of Hispanics living in Puerto Rico is composed mostly of diverse CST profiles with decreased Lactobacillus and is associated with a higher pro-inflammatory environment. The joint host-microbe interaction analyses via cytokine and microbiota profiling have very good translational potential.

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.

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

Background

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

Methods

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

Results

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

Conclusion

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

Impact of cervical intraepithelial neoplasia and treatment on IVF/ICSI outcomes

STUDY QUESTION

Does treatment selection for cervical lesions affect the outcome of IVF/ICSI?

SUMMARY ANSWER

There was no difference in pregnancy outcome between treated and untreated groups, or between different types of IVF/ICSI treatment.

WHAT IS KNOWN ALREADY

Human papillomavirus (HPV) infection and HPV-induced cervical lesions are associated with decreased fertility, and cervical intraepithelial neoplasia (CIN) treatment may increase the risk of adverse pregnancy outcomes.

STUDY DESIGN, SIZE, DURATION

Between 2018 and 2020, 190 women with infertility who had abnormal HPV screening or cytology results prior to IVF/ICSI, and were diagnosed with CIN2/CIN3 by colposcopy biopsy at a tertiary hospital, were enrolled in a retrospective cohort study with follow-up until 31 December 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients with infertility who were diagnosed with CIN2/CIN3 by colposcopy biopsy were divided into the treatment and expectant management groups. The treatment group was divided into two intervention subgroups: the ablative therapy group and the surgical treatment group. The baseline data, number of oocytes retrieved, and rates of fertilization, high-quality embryos, positive serum HCG, clinical pregnancy, abortion, live birth, and cumulative pregnancy were compared among groups.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the 190 patients included in the study, 152 were diagnosed with CIN2, and 38 patients had CIN3. There was no significant difference in the baseline data between the treatment and expectant groups. The time from confirmed lesions to the onset of gonadotrophin administration in the surgical treatment group was significantly longer than in the ablative therapy group and the expectant group (P = 0.007 and P = 0.024, respectively). For the treatment and expectant groups, respectively, the average number of oocytes retrieved (12.95 ± 8.77; 13.32 ± 9.16), fertilization rate (71.01 ± 23.86; 64.84 ± 26.24), and high-quality embryo rate (48.93 ± 30.72; 55.17 ± 34.13) did not differ, and no differences were detected between the different treatment subgroups. There were no differences among groups in rates of HCG positivity, clinical pregnancy, miscarriage, live birth, or cumulative pregnancy. The live birth rate in the surgical treatment group was slightly higher than that in the expectant groups (77.78% versus 66.67%), but the difference was not statistically significant. The 3-year cumulative pregnancy rates in the surgical treatment and expectant groups were 58.19% and 64.00%, respectively.

LIMITATIONS, REASONS FOR CAUTION

This is a retrospective study, which by nature can include selection bias, and the number of cases in the expectant group was <30, which may result in a false-negative result owing to the small sample size.

WIDER IMPLICATIONS OF THE FINDINGS

For patients with CIN2/CIN3, the treatment of cervical lesions does not affect the outcome of IVF/ICSI. Patients with CIN2 can enroll for IVF/ICSI cycles, with close follow-up to prevent the progression of cervical lesions, in order to avoid further delay in starting ART. For patients with CIN3, ovulation induction and embryo cryopreservation can be initiated as soon as possible after cervical lesions are treated, and frozen-thawed embryo transfer can be carried out 9-12 months later.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the Key Clinical Projects of the Peking University Third Hospital (to Y.W., BYSYZD2021014). The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

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.

Multidimensional outlook on the pathophysiology of cervical cancer invasion and metastasis

Cervical cancer being one of the primary causes of high mortality rates among women is an area of concern, especially with ineffective treatment strategies. Extensive studies are carried out to understand various aspects of cervical cancer initiation, development and progression; however, invasive cervical squamous cell carcinoma has poor outcomes. Moreover, the advanced stages of cervical cancer may involve lymphatic circulation with a high risk of tumor recurrence at distant metastatic sites. Dysregulation of the cervical microbiome by human papillomavirus (HPV) together with immune response modulation and the occurrence of novel mutations that trigger genomic instability causes malignant transformation at the cervix. In this review, we focus on the major risk factors as well as the functionally altered signaling pathways promoting the transformation of cervical intraepithelial neoplasia into invasive squamous cell carcinoma. We further elucidate genetic and epigenetic variations to highlight the complexity of causal factors of cervical cancer as well as the metastatic potential due to the changes in immune response, epigenetic regulation, DNA repair capacity, and cell cycle progression. Our bioinformatics analysis on metastatic and non-metastatic cervical cancer datasets identified various significantly and differentially expressed genes as well as the downregulation of potential tumor suppressor microRNA miR-28-5p. Thus, a comprehensive understanding of the genomic landscape in invasive and metastatic cervical cancer will help in stratifying the patient groups and designing potential therapeutic strategies.

Microbiomes, Their Function, and Cancer: How Metatranscriptomics Can Close the Knowledge Gap

The interaction between the microbial communities in the human body and the onset and progression of cancer has not been investigated until recently. The vast majority of the metagenomics research in this area has concentrated on the composition of microbiomes, attempting to link the overabundance or depletion of certain microorganisms to cancer proliferation, metastatic behaviour, and its resistance to therapies. However, studies elucidating the functional implications of the microbiome activity in cancer patients are still scarce; in particular, there is an overwhelming lack of studies assessing such implications directly, through analysis of the transcriptome of the bacterial community. This review summarises the contributions of metagenomics and metatranscriptomics to the knowledge of the microbial environment associated with several cancers; most importantly, it highlights all the advantages that metatranscriptomics has over metagenomics and suggests how such an approach can be leveraged to advance the knowledge of the cancer bacterial environment.

Bacteria in cancer initiation, promotion and progression

Cancer cells originate from a series of acquired genetic mutations that can drive their uncontrolled cell proliferation and immune evasion. Environmental factors, including the microorganisms that colonize the human body, can shift the metabolism, growth pattern and function of neoplastic cells and shape the tumour microenvironment. Dysbiosis of the gut microbiome is now recognized as a hallmark of cancer by the scientific community. However, only a few microorganisms have been identified that directly initiate tumorigenesis or skew the immune system to generate a tumour-permissive milieu. Over the past two decades, research on the human microbiome and its functionalities within and across individuals has revealed microbiota-focused strategies for health and disease. Here, we review the evolving understanding of the mechanisms by which the microbiota acts in cancer initiation, promotion and progression. We explore the roles of bacteria in gastrointestinal tract malignancies and cancers of the lung, breast and prostate. Finally, we discuss the promises and limitations of targeting or harnessing bacteria in personalized cancer prevention, diagnostics and treatment.

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.