Composition Of Vaginal Microbiome Research Articles

O-264 Vaginal Microbiota Transplantation (VMT) for treatment of vaginal dysbiosis without the use of antibiotics – A Randomized Controlled Trial in healthy women with vaginal dysbiosis

Abstract Study question Can vaginal microbiota transplantation with shotgun-verified eubiotic vaginal microbiome over three menstrual cycles, convert vaginal dysbiosis to eubiosis in healthy women? Summary answer The RCT is ongoing until it is by March 2023. Results will be ready for presentation at EHSRE conference. What is known already Vaginal dysbiosis covers imbalances in the vaginal flora, caused by the composition of bacteria, viruses, and vaginal fungi. A large proportion of women who have vaginal dysbiosis do not experience any symptoms. Dysbiosis occurs in about 16-20% of all women. Vaginal dysbiosis is associated with infertility, euploid pregnancy loss, preterm labour or bacterial vaginosis. Treatment of vaginal dysbiosis consists of antibiotic treatment, and/or probiotics. Vaginal transplantation with eubiotic vaginal bacterial flora in combination with antibiotics has successfully been performed in four out of five recipients in an earlier study, but no study has been performed without use of antibiotic pretreatment. Study design, size, duration Randomized, controlled, double-blinded trial with a randomization ratio 3:1 to receive either a eubiotic microbiome transplant or placebo. 320 healthy women between 18 and 40 years, was enrolled for screening of vaginal dysbiosis. 30 donors with a eubiotic vaginal microbiome and 48 recipients with a dysbiotic microbiome were identified. The trial began in June 2021 and will end in March 2023 Participants/materials, setting, methods Vaginal microbiome composition was assed by next-generation ShotGun sequencing. To qualify as donor bacterial DNA from a vaginal swab had to show a bacterial composition of at least 80% lactobacilli and less than 5% pathogenic bacteria. To qualify as recipient vaginal microbiome composition should be with at least 20% pathogenic bacteria and no more than 10% lactobacilli. The recipient could have up to three attempts of VMT treatments with a follow-up period of 6 months. Main results and the role of chance We expect the RCT to end in March 2023, and the results of this trial will be presented at the ESHRE annual meeting . If we can show engraftment of a eubiotic microbiome transplant without the use of pre-treatment with antibiotics it could be a potential treatment of vaginal dysbiosis. Limitations, reasons for caution As this is the first VMT without antibiotic pretreatment we did not have reliable data for our power calculation and a negative result may be due to lack of statistical power. Wider implications of the findings Effective treatments for vaginal dysbiosis are urgently needed and VMT may be one such treatment strategy. Trial registration number NCT04855006

Vaginal Microbiome Dysbiosis is Associated with the Different Cervical Disease Status

Vaginal microbiome composition was demonstrated to be associated with cervical disease. The colonization characteristics of vaginal microbes and their association with the different cervical disease status, especially cervical cancer (CC), are rarely investigated. In this cross-sectional study, we characterized the vaginal microbiome of women with different status of cervical diseases, including 22 NV + (normal tissue with HPV infection), low-grade squamous intraepithelial lesion (LSIL, n = 45), high-grade squamous intraepithelial lesion (HSIL, n = 36) and CC (n = 27) using bacterial 16S DNA sequencing. Thirty HPV-negative women with normal tissue were used as the control group. We found that higher diversity of microbiome with gradual depletion of Lactobacillus, especially L. crispatus, was associated with the severity of cervical disease. High-risk HPV16 infection was associated with higher microbiome diversity and depletion of Lactobacillus in high-grade cervical diseases (i.e. HSIL and CC). The CC group was characterized by higher levels of Fannyhessea vaginae, Prevotella, Bacteroides, Finegoldia, Vibrio, Veillonella, Peptostreptococcus, and Dialister. Co-occurrence network analyses showed that negative correlations were exclusively observed between Lactobacillus and other bacteria, and almost all non-Lactobacillus bacteria were positively correlated with each other. In particular, the most diverse and complex co-occurrence network of vaginal bacteria, as well as a complete loss of L. crispatus, was observed in women with CC. Logistic regression model identified HPV16 and Lactobacillus as significant risk and protective factors for CC, respectively. These results suggest that specific Lactobacillus species (e.g. L. crispatus and L. iners) can be used as important markers to target prevention measures prioritizing HPV16-infected women and other hrHPV-infected women for test, vaccination and treat initiatives.

Maternal vaginal microbiome composition does not affect development of the infant gut microbiome in early life.

Birth mode has been implicated as a major factor influencing neonatal gut microbiome development, and it has been assumed that lack of exposure to the maternal vaginal microbiome is responsible for gut dysbiosis among caesarean-delivered infants. Consequently, practices to correct dysbiotic gut microbiomes, such as vaginal seeding, have arisen while the effect of the maternal vaginal microbiome on that of the infant gut remains unknown. We conducted a longitudinal, prospective cohort study of 621 Canadian pregnant women and their newborn infants and collected pre-delivery maternal vaginal swabs and infant stool samples at 10-days and 3-months of life. Using cpn60-based amplicon sequencing, we defined vaginal and stool microbiome profiles and evaluated the effect of maternal vaginal microbiome composition and various clinical variables on the development of the infant stool microbiome. Infant stool microbiomes showed significant differences in composition by delivery mode at 10-days postpartum; however, this effect could not be explained by maternal vaginal microbiome composition and was vastly reduced by 3 months. Vaginal microbiome clusters were distributed across infant stool clusters in proportion to their frequency in the overall maternal population, indicating independence of the two communities. Intrapartum antibiotic administration was identified as a confounder of infant stool microbiome differences and was associated with lower abundances of Escherichia coli, Bacteroides vulgatus, Bifidobacterium longum and Parabacteroides distasonis. Our findings demonstrate that maternal vaginal microbiome composition at delivery does not affect infant stool microbiome composition and development, suggesting that practices to amend infant stool microbiome composition focus factors other than maternal vaginal microbes.

Mycobiome Study Reveals Different Pathogens of Vulvovaginal Candidiasis Shape Characteristic Vaginal Bacteriome.

Vulvovaginal candidiasis (VVC) can alter the vaginal microbiome composition and structure, and this may be correlated with its variable treatment efficacy. Integrated analysis of the mycobiome and bacteriome in VVC could facilitate accurate diagnosis of infected patients and further decipher the characterized bacteriome in different types of VVC. Our mycobiome analysis determined two common types of VVC, which were clustered into two community state types (CSTs) featured by Candida glabrata (CST I) and Candida albicans (CST II). Subsequently, we compared the vaginal bacteriome in two CSTs of VVC and two other types of reproductive tract infections (RTIs), bacterial vaginosis (BV) and Ureaplasma urealyticum (UU) infection. The vaginal bacteriome in VVC patients was between the healthy and other RTIs (BV and UU) status, it bore the greatest resemblance to that of healthy subjects. While BV and UU patients have the unique vaginal microbiota community structure, which very different with healthy women. Compared with CST II, the vaginal bacteriome of CST I VVC was characterized by Prevotella, a key signature in BV. In comparison, CST II was featured by Ureaplasma, the pathogen of UU. The findings of our study highlight the need for co-analysis and simultaneous consideration of vaginal mycobiome and bacteriome in the diagnosis and treatment of VVC to solve common clinical problems, such as unsatisfactory cure rates and recurrent symptoms. IMPORTANCE Fungi headed by C. albicans play a critical role in VVC but are not sufficient for its occurrence, indicating the involvement of other factors, such as the vaginal bacteriome. We found that different CST correspond to different bacterial composition in patients with VVC, and this could underlie the alteration of vaginal microorganism environment in VVC patients. We believe that this correlation should not be ignored, and it may be related to the unsatisfactory treatment outcomes and high recurrence rate of VVC. Here, we provided evidence for associations between vaginal bacteriome patterns and fungal infection. Screening specific biomarkers for three common RTIs paves a theoretical basis for further development of personalized precision treatment.

Joint effects of individual socioeconomic status and residential neighborhood context on vaginal microbiome composition.

The vaginal microbiome is a dynamic ecosystem that is important for women's health. Its composition has been associated with risk for menopausal symptoms, sexually transmitted infections, gynecologic cancer, and preterm birth. Conventional risk factors for a vaginal microbiome linked with these adverse health outcomes include sexual behaviors, hygiene practices, individual social factors, and stress levels. However, there has been limited research on socio-contextual determinants, and whether neighborhood context modifies the association with individual socioeconomic factors. Socioeconomically diverse pregnant African American women in Atlanta, Georgia (n = 439) provided residential addresses and first trimester vaginal swab samples, which underwent sequencing, taxonomic classification, and assignment into mutually exclusive CST (community state types) via hierarchical clustering. Linear probability models were used to estimate prevalence differences (PD) for the associations of neighborhood factors with vaginal microbiome CST and to evaluate for additive interaction with maternal level of education, health insurance type, and recruitment hospital. Factors such as higher (vs. lower) maternal education, private (vs. public) insurance, and private (vs. public) hospital were associated with higher prevalence of Lactobacillus-dominant vaginal microbiome CSTs typically associated with better health outcomes. When considering the joint effects of these individual socioeconomic status and residential neighborhood factors on vaginal microbiome CST, most combinations showed a greater than additive effect among the doubly exposed; however, in the case of local income homogeneity and local racial homogeneity, there was evidence of a crossover effect between those with less-advantaged individual socioeconomic status and those with more-advantaged individual socioeconomic status. Compared to women at the public hospital who lived in economically diverse neighborhoods, women at the private hospital who lived in economically diverse neighborhoods had a 21.9% higher prevalence of Lactobacillus-dominant CSTs, while women at the private hospital who lived in less economically diverse neighborhoods (the doubly exposed) had only an 11.7% higher prevalence of Lactobacillus-dominant CSTs, showing a crossover effect (interaction term p-value = 0.004). In this study, aspects of residential neighborhood context were experienced differently by women on the basis of their individual resources, and the joint effects of these exposures on vaginal microbiome CST showed a departure from simple additivity for some factors.

Compositional Changes in the Vaginal Bacterial Microbiome of Healthy Pregnant Women across the Three Gestational Trimesters in Ismailia, Egypt

The composition of the vaginal microbiome may lead to adverse pregnancy outcomes. Normal pregnancy is associated with changes in the vaginal bacterial community composition, which tend to be more enriched with one or two Lactobacillus species promoting a healthy vagina and favorable birth outcomes. The aim of the current study was to determine compositional changes in the healthy vaginal microbiome composition during the three trimesters of pregnancy in Ismailia, Egypt using Illumina MiSeq sequencing of the V3-V4 region of the 16S rRNA. The phylum Firmicutes and the genus Lactobacillus dominated across the three trimesters of pregnancy. L. iners was the most abundant species. However, L. coleohominis and L. reuteri represented the least dominant vaginal lactobacilli. Core microbiome analyses showed the Lactobacillus genus and L. iners species to have the highest prevalence in all the samples of our study groups. The phylum Firmicutes was found to be negatively correlated with almost all other vaginal phyla during pregnancy. Likewise, a negative correlation between Lactobacillus and almost all other genera was detected, including significant negative correlations with Dialister and Prevotella. Furthermore, negative correlations of L. iners were detected with almost all other species, including a significant negative correlation with L. helveticus, G. vaginalis, S. anginosus, and S. agalactiae.

Alterations of the vaginal microbiome in healthy pregnant women positive for group B Streptococcus colonization during the third trimester

BackgroundStreptococcus agalactiae or group B Streptococcus (GBS) asymptomatically colonizes the genitourinary tracts of up to 30% of pregnant women. Globally, GBS is an important cause of neonatal morbidity and mortality. GBS has recently been linked to adverse pregnancy outcomes. The potential interactions between GBS and the vaginal microbiome composition remain poorly understood. In addition, little is known about the vaginal microbiota of pregnant Egyptian women.ResultsUsing V3-V4 16S rRNA next-generation sequencing, we examined the vaginal microbiome in GBS culture-positive pregnant women (22) and GBS culture-negative pregnant women (22) during the third trimester in Ismailia, Egypt. According to the alpha-diversity indices, the vaginal microbiome of pregnant GBS culture-positive women was significantly more diverse and less homogenous. The composition of the vaginal microbiome differed significantly based on beta-diversity between GBS culture-positive and culture-negative women. The phylum Firmicutes and the family Lactobacillaceae were significantly more abundant in GBS-negative colonizers. In contrast, the phyla Actinobacteria, Tenericutes, and Proteobacteria and the families Bifidobacteriaceae, Mycoplasmataceae, Streptococcaceae, Corynebacteriaceae, Staphylococcaceae, and Peptostreptococcaceae were significantly more abundant in GBS culture-positive colonizers. On the genus and species levels, Lactobacillus was the only genus detected with significantly higher relative abundance in GBS culture-negative status (88%), and L. iners was the significantly most abundant species. Conversely, GBS-positive carriers exhibited a significant decrease in Lactobacillus abundance (56%). In GBS-positive colonizers, the relative abundance of the genera Ureaplasma, Gardnerella, Streptococcus, Corynebacterium, Staphylococcus, and Peptostreptococcus and the species Peptostreptococcus anaerobius was significantly higher. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways related to the metabolism of cofactors and vitamins, phosphatidylinositol signaling system, peroxisome, host immune system pathways, and host endocrine system were exclusively enriched among GBS culture-positive microbial communities. However, lipid metabolism KEGG pathways, nucleotide metabolism, xenobiotics biodegradation and metabolism, genetic information processing pathways associated with translation, replication, and repair, and human diseases (Staphylococcus aureus infection) were exclusively enriched in GBS culture-negative communities.ConclusionsUnderstanding how perturbations of the vaginal microbiome contribute to pregnancy complications may result in the development of alternative, targeted prevention strategies to prevent maternal GBS colonization. We hypothesized associations between inferred microbial function and GBS status that would need to be confirmed in larger cohorts.

O-024 Does a vaginal lactobacilli probiotic treatment improve an unfavourable vaginal microbiome before fertility treatment? A randomised, double-blinded, placebo-controlled trial

Abstract Study question Does treatment with lactobacilli-loaded vaginal capsules improve an unfavourable vaginal microbiome associated with a lower implantation chance before fertility treatment? Summary answer Probiotic treatment did not improve the vaginal microbiome compared with placebo. However, spontaneous improvement of the vaginal microbiome was observed in 34.2% of all participants. What is known already Studies have shown that the vaginal microbiota composition is predictive of IVF treatment outcome and suggest that dysbiosis in the reproductive tract negatively affects the chance of pregnancy through as yet unclear mechanisms. Tests designed to assess different components of endometrial function are entering clinical practice and with microbiota being shown to modulate organ function throughout the body, interest is growing in assessing the vaginal microbiome as a potentially treatable marker of endometrial receptivity and predictor of treatment outcome. Study design, size, duration This randomised, double-blinded, placebo-controlled study was conducted at a single University fertility clinic between April 2019 and February 2021. The vaginal microbiome composition of eligible patients referred for IVF treatment was determined using a validated PCR based IS-pro technique dividing samples into three overall profiles: low, medium, and high quality. Seventy-four women with an unfavourable vaginal microbiome (low or medium profile) were included and randomly assigned 1:1 to receive either vaginal probiotic capsules or placebo. Participants/materials, setting, methods Following screening and inclusion, participants completed a 10-day treatment with vaginal probiotic capsules (containing >108 CFU of Lactobacillus gasseri and >108 CFU Lactobacillus rhamnosus) or placebo. Samples to determine the effect on the vaginal microbiome were taken following completion of treatment (primary outcome) and again in the subsequent menstrual cycle (secondary outcome). Improvement in the microbiome was defined as a shift from low to medium, low to high, or medium to high profiles. Main results and the role of chance Seventy-seven women were randomised, 74 women completed the intervention and follow-up. Randomisation yielded 38 women in the lactobacilli group and 36 women in the placebo group. The demographic and baseline characteristics were similar in the two groups. Primary outcome: the vaginal microbiome improved after intervention in 34.2% of all participants with no significant difference between the two groups (lactobacilli group 28.9%, placebo group 40.0%), RR = 0.72 (95% CI 0.38–1.38), P = 0.32. Similarly, in the cycle after intervention (secondary outcome), the vaginal microbiome composition was improved relative to baseline samples in 31.9% of all participants with no significant difference between the groups (lactobacilli group 30.6%, placebo group 33.3%), RR = 0.92 (95% CI 0.47–1.80), P = 0.80. Limitations, reasons for caution The intervention did not include all strains of lactobacilli implicated in influencing fertility outcomes. The broad categorisation of the vaginal microbiome profile as either low, medium or high may mask more subtle changes. Wider implications of the findings This study indicates that administering vaginal lactobacilli probiotics may not improve a suboptimal vaginal microbiome. However, a spontaneous improvement rate of 34.2% over a period of one to three months may provide the basis for an alternative therapeutic strategy of postponing fertility treatment until spontaneous improvement occurs. Trial registration number ClinicalTrials.gov identifier NCT03843112. EU Clinical Trials Register (EudraCT number: 2018 002376-41).

Host and Microbiome Interplay Shapes the Vaginal Microenvironment.

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

Identification of vaginal microbiome associated with IVF pregnancy

The factors that cause a preterm birth (PTB) are not completely understood up to date. Moreover, PTB is more common in pregnancies achieved by in-vitro fertilization (IVF) than in spontaneous pregnancies. Our aim was to compare the composition of vaginal microbiome at 12 weeks of gestation between women who conceived naturally or through IVF in order to study whether IVF PTB-risk could be related to vaginal microbiome composition. We performed an observational, prospective and multicentre study among two public hospitals and a fertility private clinic in Spain. Vaginal swabs from 64 pregnant women at 12 weeks of gestation were collected to analyse the microbiome composition by sequencing the V3–V4 region of the 16S rRNA. Our results showed that the vaginal microbiome signature at 12 weeks of pregnancy was different from women who conceived naturally or through IVF. The beta diversity and the genus composition were different between both cohorts. Gardnerella, Neisseria, Prevotella, and Staphylococcus genus were enriched genus in the vaginal microbiome from the IVF group, allowing us to create a balance model to predict both cohorts. Moreover, at species level the L. iners abundance was higher and L. gasseri was lower in the IVF group. As a conclusion, our findings were consistent with a proposed framework in which IVF pregnancy are related to risk for preterm birth (PTB) suggesting vaginal microbiome could be the reason to the relation between IVF pregnancy and risk for PTB.

113 Effects of Maternal Parity and Prebiotics on the Microbiome of Nursery Pigs

Abstract The objective of this study was to investigate the effect of maternal parity on sow and offspring microbiomes, and the influence of parity on pig fecal microbiome and performance in response to a prebiotic post-weaning. Fecal and vaginal swabs were collected from 22 primiparous and 74 multiparous sows in a commercial farm at weaning. Fecal swabs were also collected from 48 randomly selected piglets (n = 24, from primiparous and multiparous sows respectively) at d 0, 21, and 42 post-weaning. At weaning, piglets were allotted into 3 dietary treatment groups: a standard nursery diet including pharmacological doses of Zn and Cu (CTRL), a group fed a commercial prebiotic only (PRE), and a group fed the prebiotic plus Zn and Cu (PRE+ZnCu). Extracted DNA was sequenced on the MiSeq platform targeting the V4 variable region of the 16S rRNA bacterial gene, and sequence data were analyzed using DADA2 plus various packages within the R statistical software. Although there were no differences in vaginal microbiome composition between primiparous and multiparous sows, fecal microbiome composition was different (PERMANOVA, R2 = 0.02, P = 0.03). The fecal microbiomes of primiparous offspring displayed significantly higher bacterial diversity compared with multiparous offspring at d0 and d21 (Shannon’s H, P < 0.01), with differences in community composition observed at d21 only (PERMANOVA, R2 = 0.03, P = 0.04). When analyzing the effects of maternal parity within each treatment, only the PRE diet showed significant compositional distinctions between primiparous and multiparous microbiomes (d21: PERMANOVA, R2 = 0.13, P = 0.01; d42: PERMANOVA, R2 = 0.19, P = 0.001). Compositional differences in pig fecal microbiomes between treatments, regardless of maternal parity, were observed only at d21 (PERMANOVA, R2 = 0.12, P = 0.001). No significant differences in growth performance between treatment groups were observed. These results indicate that maternal parity influences pig gut microbiomes post-weaning, and may influence the effects of dietary prebiotics on nursery pig microbiomes.

Abstract PR-14: A synergy between the vaginal microbiome and HPV may have explanatory value for racial disparities in risk of pre-cervical cancer

Abstract The vaginal microbiome (VMB) is suggested to be a key player in high-risk Human Papilloma Virus (HPV) infection persistence, leading to the development of cervical intraepithelial neoplasia (CIN). While it is generally accepted that the VMB of women with CIN differs from that of healthy women, the VMB composition before a woman develops CIN has not been well studied. Moreover, no studies have evaluated the role of self-reported race on the VMB-CIN relationship, despite reports that the VMB of non-Latina Black (Black) women generally exhibits increased microbial diversity (often associated with HPV tumorigenesis) and lower prevalence of taxa such as Lactobacillus (reported to have an inverse association with severity of cervical abnormalities) compared to their non-Latina White (White) counterparts. Black women have higher HPV prevalence than Whites (39% vs. 24%), and more persistent HPV infections (601 days vs. 316 days, respectively), despite having a similar number of HPV infections to Whites. This suggests that factors beyond multiple HPV exposures sustain the infection. We hypothesize that HPV and the VMB may interact differently by race, to promote development of CIN. Methods: We used 16S-RNA profiles from the VMB of 3,050 consented women visiting the Virginia Commonwealth University clinics for their annual routine exam between August 2009 and November 2013. Of these, 259 had evidence of subsequent CIN after the VMB sample collection, through October 2020. The VMB profiles were characterized into three groups as “Lactobacillus (L) crispatus” group (including L. crispatus, L. gasseri and L. jensenii), “L. iners” group and “Other” based on a priori knowledge of profiled taxa. The “Other” subgroup included taxa, such as G. vaginalis, A vaginae, and others usually associated with bacterial vaginosis-like states. We used self-reported health histories, confirmed by electronic health records to determine HPV status and obtain other socio-demographic information. Multivariable logistic regression models were adjusted for age, smoking, VMB, HPV, marital and pregnancy status. Results: The cohort was mainly Black (70%), and the VMB prevalence by group was 19%, 30% and 51% for L. crispatus, L. iners, and Other, respectively. Twelve percent reported having an HPV diagnosis in the past, and 302 (10%) women developed CIN during an average of 3.6 years of follow-up (259 with CIN 1/2 and 43 with CIN3+). In crude analyses, risk of CIN was 80% higher for Black women (RR=1.8, p<0.0001) compared to Whites. However, a significant interaction between HPV status and the VMB revealed that the risk of a CIN diagnosis for HPV+ Black women with the “Other” VMB subtype, is five-fold (RR=5.3, p<0.40) the risk for Whites. Conclusions: These preliminary results suggest that interactions between the VMB and HPV may account for the differential risk of CIN by race. If replicated in further analyses, VMB profiling could help elucidate the basis of CIN racial disparities. Citation Format: Katherine Y. Tossas, Jinlei Zhao, Myrna Serrano, Jerome Strauss, Victoria Seewaldt, Gregory Buck, Robert A. Winn. A synergy between the vaginal microbiome and HPV may have explanatory value for racial disparities in risk of pre-cervical cancer [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PR-14.

Lactobacilluscrispatus dominance in the vaginalmicrobiome reduces the occurrence of spontaneouspreterm birth in women with a short cervical length

Introduction: The majority of pregnant women with a short cervix will deliver at term and, thus, may unnecessarily receive advanced monitoring and treatment. It is still necessary to define more accurately which sub-population of women with a short cervix is at elevated risk for early delivery. Objective: To determine if vaginal microbiome composition influenced the rate of spontaneous preterm birth in women with a short cervical length. Methods: In an exploratory, observational prospective study, vaginal secretions were obtained from 591 women at 21–24 week gestation. Vaginal microbiome composition was determined by analyzing the V1–V3 region of the bacterial 16S ribosomal RNA gene. Results: Lactobacillus crispatus was numerically dominant in the vagina in 41.7% of subjects, followed by L. iners in 32% and Gardnerella vaginalis in 12%. In women whose cervix was ≤25mm, the sensitivity to predict an spontaneous preterm birth was 11.8%. However, when L. crispatus was not the dominant vaginal bacterium, this sensitivity increased to 81.8%. Similarly, in women with a cervical length ≤30mm, the sensitivity to predict an spontaneous preterm birth increased from 21.7 to 78.3% when L. crispatus was not the dominant vaginal bacterium.In women with a prior spontaneous preterm birth and a cervix ≤25 or ≤30mm, L. crispatus dominance was also associated with a reduced rate of spontaneous preterm birth in the current pregnancy (p<0.001). Conclusion: In pregnant women with a cervix ≤25mm or ≤30mm, the risk for an spontaneous preterm birth is increased if L. crispatus is not dominant in the vagina.

Influence of Maternal Microbiome and Inflammatory Response in Preterm Birth: Recent Aspects of the Prevention of Preterm Birth

Preterm birth (PTB) is a global health issue and one of the most challenging problems affecting 12.9 million births worldwide. PTB is a multi-etiological disease and remains incompletely understood. The major cause of PTB is infection or inflammation and disruption of the vaginal microbiome, which affects the maternal immunologic response leading to PTB. The vaginal microbiome composition changes by a shift in the community are typically dominated by Lactobacillus during pregnancy. There are complex interactions between the maternal microbiome in pregnancy and the development of PTB, therefore, researchers have struggled to connect the maternal microbiome with the dysregulation of the maternal immune response in cases of PTB. The host microbiome affects alterations of the microorganisms with external stimuli such as disease, nutrition, immunity, and behavior. In this review, we discuss the complex association between the maternal microbiome and the risk of PTB and also focus on recent aspects of the prevention of PTB.

Modelling Bacterial Metabolite Regulation of Vaginal Epithelial Cell Signaling in Bacterial Vaginosis

Background and Hypothesis
 Bacterial vaginosis, which is the imbalance of normal vaginal microbiota, contributes to preterm delivery, vaginitis, and decreased drug efficacy. Despite metronidazole efficacy in reducing BV contributing organisms, BV continues to recur in 50% of patients. Previous studies showing imidazole propionate’s role in the pathogenesis of type II diabetes suggest that similar metabolite-regulated pathways in vaginal microbiomes may be the key in pathogenesis of uterine diseases such as BV. Thus, the purpose of this study was to observe the relationship between vaginal metabolites, host or microbiome-derived, and transcriptomic responses in vaginal epithelial tissues stratified by vaginal microbiome composition (“microbiome group”). The hypothesis was that differences in vaginal microbiome composition result in differential regulation of metabolite-host pathway functional relationships.
 Project Methods
 Transcript levels and metabolite concentrations precollected from 23 East African women were processed and analyzed via R. Transcriptomic data were converted into KEGG pathway enrichment scores via ssGSEA2.0, a package within R. Enrichment scores were correlated (Spearman) with metabolite levels by microbiome group and lactobacillus dominant phenotypes, and relationships were visualized via Heatmap3 and Cytoscape.
 Results: 
 The results showed varying strengths in correlation among metabolites and KEGG pathway enrichment scores after filtering for strong correlations (R > |0.5|) and significance (p< 0.05). Nonlactobacillus dominant microbiomes showed fewer strongly associated metabolite-KEGG pathway relationships compared to the lactobacillus dominant microbiome group, specifically the imidazole-related networks.
 Conclusion: 
 In this study, variations in significant correlations among metabolites and KEGG pathways suggests that microbiome diversity may contribute to how metabolites regulate host pathways in vaginal epithelial cells. The reduced pathway interactions observed in imidazole compounds suggests that dysregulation may contribute to recurrence of bacterial vaginosis. This method of modelling could be used to characterize the regulation of critical pathways associated with the pathogenesis of bacterial vaginosis.

The vaginal microbiome in women of reproductive age with healthy weight versus overweight/obesity.

The aim of this study was to evaluate the differences between the vaginal microbiome of reproductive-aged women with overweight and obesity (Ow/Ob) compared with healthy weight (HW). In this case-control study, a cohort of 367 nonpregnant women (18 to 40 years) with Ow/Ob (BMI ≥25 kg/m2 ) was case-matched with 367 women with HW (BMI 18.0 to 24.9 kg/m2 ). The study was a secondary analysis of 16S rRNA vaginal microbiome surveys through the Vaginal Human Microbiome Study (VaHMP).Groups were matched on age, race/ethnicity, income, and nulliparity status. Mean age and BMI of Ow/Ob and HW groups were 26.8 versus 26.7 years and 37.0 versus 22.1 kg/m2 , respectively. The overall vaginal microbiome composition differed betweengroups (PERMANOVA, p = 0.035). Women with Ow/Ob had higher alpha diversity compared with women with HW (Wilcoxon test, Shannon index p = 0.025; inverse Simpson index p = 0.026). Lactobacillusdominance (≥30% proportional abundance) was observed in a greater proportion of women with HW (48.7%) compared with Ow/Ob (40.1%; p = 0.026). The vaginal microbiome differs in reproductive-aged women with Ow/Ob compared with women with HW, with increased alpha diversity and decreased predominance of Lactobacillus. Observed differences in the vaginal microbiome may partially explain differences in preterm birth and bacterial vaginosis risk between these populations.

Insights into the role of vaginal microbiome in women's health.

The vaginal microbiome is a complex and dynamic microecosystem that fluctuates continually throughout a woman's life. Lactobacillus, a bacterium that possesses antibacterial properties dominates a healthy vaginal microbiome. Bacterial vaginosis is the most common vaginal disorder that has been linked with the dysbiosis of normal vaginal microbiota. Despite the importance of vaginal microbiome, little is known about functions it performs especially, how it helps in protecting the female reproductive tract. This knowledge gap is a significant impediment to the development of effective and feasible clinical treatments that might be required to improve women's health. Thus, a deeper understanding of the functional aspects and not just the composition of vaginal microbiome may aid in improving the diagnostics and treatment strategies. Recent advancement in molecular methods and computational biology have allowed researchers to acquire more knowledge about the vaginal microbiome. The use of metagenomics (culture-independent high-throughput technology) and bioinformatics tools have improved our understanding of the vaginal microbiome. In this review, we have attempted to explore the factors that may alter normal vaginal microbiota homeostasis such as age, sexual behavior, ethnicity, and hygiene, and so forth. We also discuss the role of probiotics in restoring healthy vaginal microbiome.

Vaginal and Anal Microbiome during Chlamydia trachomatis Infections.

Background.Chlamydia trachomatis (CT) is the agent of the most common bacterial sexually transmitted infection worldwide, with a significant impact on women’s health. Despite the increasing number of studies about the vaginal microbiome in women with CT infections, information about the composition of the anal microbiome is still lacking. Here, we assessed the bacterial community profiles of vaginal and anal ecosystems associated or not with CT infection in a cohort of Caucasian young women. Methods. A total of 26 women, including 10 with a contemporary vaginal and ano-rectal CT infection, were enrolled. Composition of vaginal and anal microbiome was studied by 16S rRNA gene profiling. Co-occurrence networks of bacterial communities and metagenome metabolic functions were determined. Results. In case of CT infection, both vaginal and anal environments were characterized by a degree of dysbiosis. Indeed, the vaginal microbiome of CT-positive women were depleted in lactobacilli, with a significant increase in dysbiosis-associated bacteria (e.g., Sneathia, Parvimonas, Megasphaera), whereas the anal microbiota of CT-infected women was characterized by higher levels of Parvimonas and Pseudomonas and lower levels of Escherichia. Interestingly, the microbiome of anus and vagina had numerous bacterial taxa in common, reflecting a significant microbial ‘sharing’ between the two sites. In the vaginal environment, CT positively correlated with Ezakiella spp. while Gardnerella vaginalis co-occurred with several dysbiosis-related microbes, regardless of CT vaginal infection. The vaginal microbiome of CT-positive females exhibited a higher involvement of chorismate and aromatic amino acid biosynthesis, as well as an increase in mixed acid fermentation. Conclusions. These data could be useful to set up new diagnostic/prognostic tools, offering new perspectives for the control of chlamydial infections.

Cervical Squamous Intraepithelial Lesions Are Associated with Differences in the Vaginal Microbiota of Mexican Women.

ABSTRACTCervical cancer is an important health concern worldwide and is one of the leading causes of death in Mexican women. Previous studies have shown changes in the female genital tract microbe community related to human papillomavirus (HPV) infection and cervical cancer; yet, this link remains unexplored in many human populations. This study evaluated the vaginal bacterial community among Mexican women with precancerous squamous intraepithelial lesions (SIL). We sequenced the V3 region of the 16S rRNA gene in cervical samples from 228 Mexican women, including 121 participants with SIL, most of which were HPV positive, and 107 healthy women without HPV infection or SIL. The presence of SIL was associated with changes in composition (beta diversity) and with a higher species richness (Chao1). A comparison of HPV-positive women with and without SIL showed that microbiota changes occurred even in the absence of SIL. Multivariate association with linear models (MaAsLin) analysis yielded independent associations between HPV infection and an increase in the relative abundance of Brachybacterium conglomeratum and Brevibacterium aureum as well as a decrease in two Lactobacillus iners operational taxonomic units (OTUs). We also identified a positive independent association between HPV-16, the most common HPV subtype linked to SIL, and Brachybacterium conglomeratum. Our work indicates that HPV infection leading to SIL is primarily associated with shifts in vaginal microbiota composition, some of which may be specific to this human population.IMPORTANCE Human papillomavirus (HPV) plays a critical role in cervical carcinogenesis but is not sufficient for cervical cancer development, indicating the involvement of other factors. The vaginal microbiota is an important factor in controlling infections caused by HPV, and, depending on its composition, it can modulate the microenvironment in vaginal mucosa against viral infections. Ethnic and sociodemographic factors influence differences in vaginal microbiome composition, which underlies the dysbiotic patterns linked to HPV infection and cervical cancer across different populations of women. Here, we provide evidence for associations between vaginal microbiota patterns and HPV infection linked to ethnic and sociodemographic factors. To our knowledge, this is the first report of the species Brevibacterium aureum and Brachybacterium conglomeratum linked to HPV infection or squamous intraepithelial lesions (SIL).

Relationship between Papillomavirus vaccine, vaginal microbiome, and local cytokine response: an exploratory research

The influence of vaccination on composition of the human microbiome at distinct sites has been recognized as an essential component in the development of new vaccine strategies. The HPV vaccine is widely used to prevent cervical cancer; however, the influence of HPV vaccine on the vaginal microbiota has not been previously investigated. In his study, we performed an initial characterization of the microbiome and cytokine composition in the vagina following administration of the bivalent vaccine against HPV 16/18. In this exploratory study, fifteen women between 18 and 40years received three doses of the HPV-16/18 AS04-adjuvanted vaccine (Cervarix®). Cervicovaginal samples were collected before the first dose and 30days after the third dose. HPV genotyping was performed by the XGEN Flow Chip technique. The cytokines IFN-γ, IL-2, IL-12p70, TNF-α, GM-CSF, IL-4, IL-5, IL-10, and IL-13 were quantitated by multiplex immunoassay. The vaginal microbiome was identified by analysis of the V3/V4 region of the bacterial 16S rRNA gene. The most abundant bacterial species in the vaginal microbiome was Lactobacillus crispatus, followed by L. iners. Bacterial diversity and dominant organisms were unchanged following vaccination. Small decreases in levels of pro and anti-inflammatory cytokines were observed following HPV vaccination, but there was no association between vaginal cytokine levels and microbiome composition. Vaginal microbiome is not altered following administration of the standard three-dose HPV-16/18 AS04-adjuvanted (Cervarix®) vaccine.