HPV-associated cervicovaginal microbiome and host metabolome characteristics.

BACKGROUND: Cervicovaginal microbiome plays an important role in the persistence of HPV infection and subsequent disease development. However, cervicovaginal microbiota varied cross populations with different habits and regions. Identification of population-specific biomarkers from cervicovaginal microbiota and host metabolome axis may support early detection or surveillance of HPV-induced cervical disease at all sites. Therefore, in the present study, to identify HPV-specific biomarkers, cervicovaginal secretion and serum samples from HPV-infected patients (HPV group, n = 25) and normal controls (normal group, n = 17) in Xichang, China were collected for microbiome (16S rRNA gene sequencing) and metabolome (UHPLC-MS/MS) analysis, respectively. RESULTS: The results showed that key altered metabolites of 9,10-DiHOME, α-linolenic acid, ethylparaben, glycocholic acid, pipecolic acid, and 9,12,13-trihydroxy-10(E),15(Z)-octadecadienoic acid, correlating with Sneathia (Sneathia_amnii), Lactobacillus (Lactobacillus_iners), Atopobium, Mycoplasma, and Gardnerella, may be potential biomarkers of HPV infection. CONCLUSION: The results of current study would help to reveal the association of changes in cervicovaginal microbiota and serum metabolome with HPV infections.

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

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

Impact of exposure to air pollution on cervicovaginal microbial communities.

PURPOSE: Vaginal microbial communities can be dominated by anaerobic (community state type IV, CST IV) or Lactobacillus (other CSTs) species. CST IV is a risk factor for spontaneous preterm birth (sPTB) and is more common among Black than White populations. In the US, average air pollution exposures are higher among Black compared to White people and exert systemic health effects. We sought to (1) quantify associations of air pollution, specifically particulate matter <2.5 µm in diameter (PM2.5), with CST IV and (2) explore the extent to which racial disparities in PM2.5 exposure might explain racial differences in the prevalence of CST IV. DESIGN: Methods: We performed a secondary analysis of 566 participants of the Motherhood & Microbiome study. PM2.5 exposures were derived from a machine learning model integrating NASA satellite and EPA ground monitor data. Previously, cervicovaginal swabs from 15 to 20 weeks' gestation were analyzed using 16 S rRNA sequencing and hierarchical clustering assigned CSTs. Multivariable logistic regression models calculated adjusted odds ratios of CST IV (vs. other CSTs) per interquartile range (IQR) increment of PM2.5. Race-stratified and mediation analyses were performed. RESULTS: Higher PM2.5 exposure was associated with CST IV (aOR 1.39, 95% CI 1.02-1.91). Further adjustment for race/ethnicity attenuated the association (aOR 1.34, 95% CI: 0.97-1.83). Black participants (vs. White) had higher median PM2.5 exposure (10.6 vs. 9.6 µg/m3, P < 0.001) and higher prevalence of CST IV (47% vs. 11%, P < 0.001). Mediation analysis revealed that higher PM2.5 exposure may explain 3.9% (P = 0.038) and 3.3% (P = 0.15) of the Black-White disparity in CST IV in unadjusted and adjusted models, respectively. CONCLUSION: PM2.5 was associated with CST IV, a risk factor for sPTB. Additionally, PM2.5 exposure may partially explain racial differences in the prevalence of CST IV. Further research is warranted to discover how environmental exposures affect microbial composition and perpetuate racial health disparities.

Adverse effect of lactobacilli-depauperate cervicovaginal microbiota on pregnancy outcomes in women undergoing frozen-thawed embryo transfer.

Purpose: The cervicovaginal microbiota is essential for maintaining the health of the female reproductive tract. However, whether cervicovaginal microbiota status prior to frozen embryo transfer (FET) associates with pregnancy outcomes is largely unexplored. Methods: Cervical mucus from 29 women who had undergone FET was collected. Microbial composition was analyzed using 16 S rRNA gene sequence to assess the correlation to the pregnancy outcomes. Results: CST-categorized Lactobacillus was the most dominant (41.71%) in the pregnant group, while CST-IV-based and BV-related Gardnerella (34.96%) prevailed in the non-pregnant group. The average abundance of Gardnerella compared non-pregnant to pregnant women was the highest (34.96% vs. 4.22%, p = 0.0015) among other CST-IV indicator bacteria. Multivariate analysis revealed that CST-IV-related bacteria have a significantly adverse effect on ongoing pregnancy outcomes (odds ratio, 0.083; 95% confidence index, 0.012-0.589, p = 0.013*). Conclusions: The study found that the CST-IV microbiota, with significantly increasing Gardnerella and the loss of Lactobacilli as the dominant bacteria, can potentially contribute to pregnancy failure. Therefore, dysbiotic microbiota may be a risk factor in women undergoing FET. Assessing the health of the cervicovaginal microbiota prior to FET would enable couples to make a more thoughtful decision on the timing and might improve pregnancy outcomes.

Prevotella as the hub of the cervicovaginal microbiota affects the occurrence of persistent human papillomavirus infection and cervical lesions in women of childbearing age via host NF-κB/C-myc.

There is evidence that coinfection of cervicovaginal high-risk human papillomavirus (HR-HPV) and bacteria is common in women of childbearing age. However, the relationship between bacterial vaginosis (BV) and persistent HR-HPV infection in women of childbearing age and the underlying mechanisms remain unclear. In this study, we determined whether BV affects persistent HR-HPV infection in women aged 20-45 years and explored the possible mechanisms of their interactions. From January 1 to April 30, 2020, we recruited women aged 20-45 years with and without BV at a ratio of 1:2 from Fujian Maternity and Child Health Hospital. All women were followed up at 0, 12, and 24 months. A BV assay, HR-HPV genotyping and cervical cytology were performed at each follow-up. At 0 months, additional vaginal secretions and cervical exfoliated cells were collected for 16S ribosomal RNA sequencing, bacterial metabolite determination, and POU5F1B, C-myc, TLR4, NF-κB, and hTERT quantification. A total of 920 women were included. The abundance of Prevotella (p = 0.016) and Gardnerella (p = 0.027) were higher, whereas the abundance of Lactobacillus was lower (p = 0.001) in women with persistent HR-HPV infection and high-grade squamous intraepithelial lesions (HSIL). The abundance of Prevotella (p = 0.025) and Gardnerella (p = 0.018) increased in the vaginas of women with persistent HPV16 infection, whereas only the abundance of Prevotella (p = 0.026) was increased in women with persistent HPV18 infection. The abundance of Prevotella in the vagina was significantly positively correlated with the expression levels of TLR4, NF-κB, C-myc, and hTERT in host cervical cells (p < 0.05). Our findings suggest that overgrowth of Prevotella in the vagina may influence the occurrence of persistent HR-HPV infection-related cervical lesions through host NF-κB and C-myc signaling.

In-Silico Functional Metabolic Pathways Associated to Chlamydia trachomatis Genital Infection.

The advent of high-throughput technologies, such as 16s rDNA sequencing, has significantly contributed to expanding our knowledge of the microbiota composition of the genital tract during infections such as Chlamydia trachomatis. The growing body of metagenomic data can be further exploited to provide a functional characterization of microbial communities via several powerful computational approaches. Therefore, in this study, we investigated the predicted metabolic pathways of the cervicovaginal microbiota associated with C. trachomatis genital infection in relation to the different Community State Types (CSTs), via PICRUSt2 analysis. Our results showed a more rich and diverse mix of predicted metabolic pathways in women with a CST-IV microbiota as compared to all the other CSTs, independently from infection status. C. trachomatis genital infection further modified the metabolic profiles in women with a CST-IV microbiota and was characterized by increased prevalence of the pathways for the biosynthesis of precursor metabolites and energy, biogenic amino-acids, nucleotides, and tetrahydrofolate. Overall, predicted metabolic pathways might represent the starting point for more precisely designed future metabolomic studies, aiming to investigate the actual metabolic pathways characterizing C. trachomatis genital infection in the cervicovaginal microenvironment.

Cervicovaginal Microbiota Composition in Chlamydia trachomatis Infection: A Systematic Review and Meta-Analysis.

In healthy women, the cervicovaginal microbiota is characterized by the predominance of Lactobacillus spp., whereas the overgrowth of anaerobic bacteria leads to dysbiosis, known to increase the risk of acquiring genital infections like Chlamydia trachomatis. In the last decade, a growing body of research has investigated the composition of the cervicovaginal microbiota associated with chlamydial infection via 16s rDNA sequencing, with contrasting results. A systematic review and a meta-analysis, performed on the alpha-diversity indices, were conducted to summarize the scientific evidence on the cervicovaginal microbiota composition in C. trachomatis infection. Databases PubMed, Scopus and Web of Science were searched with the following strategy: "Chlamydia trachomatis" AND "micro*". The diversity indices considered for the meta-analysis were Operational Taxonomic Unit (OTU) number, Chao1, phylogenetic diversity whole tree, Shannon's, Pielou's and Simpson's diversity indexes. The search yielded 425 abstracts for initial review, of which 16 met the inclusion criteria. The results suggested that the cervicovaginal microbiota in C. trachomatis-positive women was characterized by Lactobacillus iners dominance, or by a diverse mix of facultative or strict anaerobes. The meta-analysis, instead, did not show any difference in the microbial biodiversity between Chlamydia-positive and healthy women. Additional research is clearly required to deepen our knowledge on the interplay between the resident microflora and C. trachomatis in the genital microenvironment.

Cervicovaginal microbiota dysbiosis correlates with HPV persistent infection.

HPV persistent infection is a main event leading to the development of cervical intraepithelial neoplasia and cervical cancer. Earlier to distinguish HPV persistent and transient infection is meaningful but the methods are limited. This study used 16S rDNA sequencing to determine the cervicovaginal microbiota of HPV persistent infection, transient infection and health women. Sequences analysis was performed and according to subsequent statistical analysis, the structure of cervicovaginal microbiota of healthy and transient infection individuals is relatively single, Firmicutes occupy the main composition. However, that of the HPV persistent infection presented a complicated trend and the abundance of Proteobacteria, Actinobacteria, Bacteroidetes and Fusobacteria was higher. The significance p-values of the average species abundance of Firmicutes, Proteobacteria and Bacteroides between HPV persistent and transient infection groups were 0.003, 0.018 and 0.005, respectively. The study also found 36 biomarkers of cervicovaginal microbiota dysbiosis for LDA score>4 among different groups. At genus level, Prevotella, Sphingomonas and Anaerococcus correlated with HPV persistent infection. At species level, Lactobacillus iners correlated with HPV transient infection. Besides, local immune microenvironment was changed with cervicovaginal microbiota dysbiosis. Interleukin-6 and TNF-α were significantly upregulated in cervical secretions from HPV persistent infection compared with those from transient infection and healthy women. Peripheral blood Regulatory T cells and myeloid-derived suppressor cells in patients with HPV persistent infection were also significantly increased. In conclusion, this study identified cervicovaginal microbiota dysbiosis closely related to HPV persistent infection, which provided a new idea and method for the prevention of cervical cancer.

Cervicovaginal microbial communities deficient in Lactobacillus species are associated with second trimester short cervix.

BACKGROUND: The cervix functions as a barrier to ascending pathogens in pregnancy. Short cervical length and lack of cervicovaginal Lactobacillus species are risk factors for spontaneous preterm birth; however, whether they interact to increase risk remains unknown. OBJECTIVE: We sought to examine the relationship between cervicovaginal microbiota and short cervix as well as their combined impact on spontaneous preterm birth risk. STUDY DESIGN: This was a secondary analysis of a prospective nested, case-control pregnancy study. Cervical swabs were collected between 16 and 20 weeks of gestation. Cervical length was measured per standard clinical care during a clinically indicated ultrasound at approximately 20 weeks of gestation. Cervicovaginal microbiota were analyzed with 16S ribosomal RNA gene sequencing and classified into community state types among 67 cases of spontaneous preterm birth, 47 cases of medically indicated preterm birth, and 358 cases of term births. Logistic regression was used to model associations of community state type IV, a community characterized by a paucity of Lactobacillus species and a wide array of anaerobic bacteria, and short cervix (<25 mm) as well as to model the association of a combination of short cervix and community state type IV with the odds of spontaneous preterm birth. RESULTS: Among the 472 women in the data set, there were 38 with short cervix (8.1%) and 177 with community state type IV (37.5%). Short cervix was associated with spontaneous preterm birth (adjusted odds ratio, 15.59; 95% confidence interval, 6.77-35.92). Women with community state type IV had higher odds of short cervix (adjusted odds ratio, 2.17; 95% confidence interval, 1.04-4.53) as well as spontaneous preterm birth (adjusted odds ratio, 1.97; 95% confidence interval, 1.06-3.65). While the interaction of community state type IV and short cervix was not significant (P = .771), women with both short cervix and community state type IV (n = 20) had higher odds of spontaneous preterm birth compared with women with both normal cervical length and community state types I, II, III, or V (n = 277) (adjusted odds ratio, 21.8; 95% confidence interval, 6.78-70.2). CONCLUSION: Community state type IV, characterized by a diverse set of strict and facultative anaerobes and a paucity of Lactobacillus species, is associated with increased odds of short cervix. Women with both community state type IV and short cervix have higher odds of spontaneous preterm birth than women with either factor alone. Determining the cascade of events leading to premature cervical shortening, including dysbiosis, may be critical in preventing spontaneous preterm birth.

Cervicovaginal microbiota composition correlates with the acquisition of high-risk human papillomavirus types.

High-risk (hr) human papillomavirus (HPV) infection is closely associated with the clinical conditions of both squamous intraepithelial lesions (SILs) and cervical carcinoma. However, it remains unclear what factors determine the type of hrHPV infection. Here, we have comprehensively investigated the bacterial composition of the cervicovaginal microbiota of 280 women infected with one type of hrHPV (HPV 16, 52 or 58) by the pyrosequencing of barcoded 16S rRNA genes. Differential microbiota composition was observed among various SIL groups and within the subgroups of each group. This result showed that it is not the microbiota diversity or the common microbiota, but rather agents that are specific to each SIL that might have a positive influence on the acquisition of hrHPV types, independent of abundance. Specifically, a composition of Oribacterium, Lachnobacterium and Thermus in the cervicovaginal microbiota is more likely to be associated with HPV 16, while a composition of Motilibacter in the cervicovaginal microbiota is more likely to be associated with HPV 52, and a composition of Litorilinea and Paludibaculum with a concomitant paucity of L. iners in the cervicovaginal microbiota is more likely to be associated with HPV 58. Furthermore, functional predictions regarding infectious diseases and cancer-related genes disclosed significant differences (p < 0.01) among the different (sub)groups. Our study provides an elucidation of the relationship between the composition of the cervicovaginal microbiota and the type of hrHPV acquired.