Composition Of Vaginal Microbiota Research Articles

Diet influences community dynamics following vaginal group B streptococcus colonization.

The vaginal microbiota plays a pivotal role in reproductive, sexual, and perinatal health and disease. Unlike the well-established connections between diet, metabolism, and the intestinal microbiota, parallel mechanisms influencing the vaginal microbiota and pathogen colonization remain overlooked. In this study, we combine a mouse model of Streptococcus agalactiae strain COH1 [group B Streptococcus (GBS)] vaginal colonization with a mouse model of pubertal-onset obesity to assess diet as a determinant of vaginal microbiota composition and its role in colonization resistance. We leveraged culture-dependent assessment of GBS clearance and culture-independent, sequencing-based reconstruction of the vaginal microbiota in relation to diet, obesity, glucose tolerance, and microbial dynamics across time scales. Our findings demonstrate that excessive body weight gain and glucose intolerance are not associated with vaginal GBS density or timing of clearance. Diets high in fat and low in soluble fiber are associated with vaginal GBS persistence, and changes in vaginal microbiota structure and composition due to diet contribute to GBS clearance patterns in nonpregnant mice. These findings underscore a critical need for studies on diet as a key determinant of vaginal microbiota composition and its relevance to reproductive and perinatal outcomes.IMPORTANCEThis work sheds light on diet as a key determinant influencing the composition of vaginal microbiota and its involvement in group B Streptococcus (GBS) colonization in a mouse model. This study shows that mice fed diets with different nutritional composition display differences in GBS density and timing of clearance in the female reproductive tract. These findings are particularly significant given clear links between GBS and adverse reproductive and neonatal outcomes, advancing our understanding by identifying critical connections between dietary components, factors originating from the intestinal tract, vaginal microbiota, and reproductive outcomes.

Vaginal microbiota and spontaneous preterm birth in pregnant women at high risk of recurrence

We describe vaginal microbiota, including Gardnerella species and sexually transmitted infections (STIs), during pregnancy and their associations with recurrent spontaneous preterm birth (sPTB). We performed a prospective cohort study in a tertiary referral centre in the Netherlands, among pregnant women with previous sPTB <34 weeks' gestation. Participants collected three vaginal swabs in the first and second trimester. Vaginal microbiota was profiled with 16S rDNA sequencing. Gardnerella species and STI's were tested with qPCR. Standard care was provided according to local protocol, including screening and treatment for bacterial vaginosis (BV), routine progesterone administration and screening for cervical length shortening. Of 154 participants, 26 (16.9 %) experienced recurrent sPTB <37 weeks' gestation. Microbiota composition was not associated with sPTB. During pregnancy, the share of Lactobacillus iners-dominated microbiota increased at the expense of diverse microbiota between the first and second trimester. This change coincided with treatment for BV, demonstrating a similar change in microbiota composition after treatment. In this cohort of high-risk women, we did not find an association between vaginal microbiota composition and recurrent sPTB. This should be interpreted with care, as these women were offered additional preventive therapies to reduce sPTB according to national guidelines including progesterone and BV treatment. The increase observed in L. iners dominated microbiota and the decrease in diverse microbiota mid-gestation was most likely mediated by BV treatment. Our findings suggest that in recurrent sPTB occurring despite several preventive therapies, the microbe-related etiologic contribution might be limited.

Effect of stress urinary incontinence on vaginal microbial communities

BackgroundPostpartum women often experience stress urinary incontinence (SUI) and vaginal microbial dysbiosis, which seriously affect women’s physical and mental health. Understanding the relationship between SUI and vaginal microbiota composition may help to prevent vaginal diseases, but research on the potential association between these conditions is limited.ResultsThis study employed 16S rRNA gene sequencing to explore the association between SUI and vaginal dysbiosis. In terms of the vaginal microbiota, both species richness and evenness were significantly higher in the SUI group. Additionally, the results of NMDS and species composition indicated that there were differences in the composition of the vaginal microbiota between the two groups. Specifically, compared to postpartum women without SUI (Non-SUI), the relative abundance of bacteria associated with bacterial dysbiosis, such as Streptococcus, Prevotella, Dialister, and Veillonella, showed an increase, while the relative abundance of Lactobacillus decreased in SUI patients. Furthermore, the vaginal microbial co-occurrence network of SUI patients displayed higher connectivity, complexity, and clustering.ConclusionThe study highlights the role of Lactobacillus in maintaining vaginal microbial homeostasis. It found a correlation between SUI and vaginal microbiota, indicating an increased risk of vaginal dysbiosis. The findings could enhance our understanding of the relationship between SUI and vaginal dysbiosis in postpartum women, providing valuable insights for preventing bacterial vaginal diseases and improving women’s health.

Abstract PR016: Viewing Native American cervical cancer disparities through the lens of the vaginal microbiome: A pilot study

Abstract Cervical cancer disproportionally affects Native American (NA) women who have higher rates of cervical cancer, are often diagnosed at later stages and are more likely to die from the disease compared to White women. This cancer disparity is primarily attributed to a lack of screening and unequal access to healthcare; however, other factors in NA women might contribute. Vaginal dysbiosis has been implicated in persistent HPV infection and cervical cancer. Yet, there is a paucity of data on the HPV infection patterns and the vaginal microbiota composition in NA communities. Here, we aimed to elucidate the relationships between HPV, microbiome, and genital inflammation to better understand how these factors relate to increased cervical cancer risk in NA women. In this cross-sectional study, we enrolled 31 women at the Native American for Community Action clinic (Flagstaff, AZ). Participants provided two self- or physician-collected vaginal swabs. Vaginal pH was also measured. One vaginal swab was used for DNA extraction and subsequent HPV genotyping and 16S rRNA gene sequencing. The microbiome analysis was conducted using QIIME 2. Levels of 48 immune mediators in the second vaginal swab were quantified by Bio-Plex. Most participants identified as American Indian or Alaska Native (n=16), White (n=11) or Hispanic (n=5). The average age was 29 years old (ranging from 18 to 46). High-risk HPV genotypes (HPV 39, 45, 52, 53, 58, 59) were detected in 23% of women (5 NA and 2 non-NA). Intriguingly, the current nonavalent HPV vaccine does not target half of genotypes detected in this cohort. Vaginal microbiota profiles were dominated by Lactobacillus in 56% of NA women, which was similar to levels observed in non-NA participants but overall lower than in previously reported non-Hispanic White cohorts. The most prevalent Lactobacillus species included L. crispatus (associated with optimal health) and L. iners (considered non-optimal). Lactobacillus-depleted profiles consisted of typical communities of anaerobes associated with bacterial vaginosis: Gardnerella, Fannyhessea, Prevotella, and Sneathia. Lactobacillus dominance was highly associated with low (≤4.5) vaginal pH (p=0.0017). Moreover, HPV-positive women tended to have lower Lactobacillus abundance compared to HPV-negative women, though this relationship was not statistically significant (p=0.07). Immune marker profiles also related to the vaginal microbiota composition with proinflammatory cytokines (IL-1beta, IL-12, IL-15 and TNFalpha) being significantly elevated (p&amp;lt;0.05) in women with Lactobacillus depletion. In addition, GM-CSF levels were decreased in women with Lactobacillus depletion, as well as in HPV-positive women. In conclusion, our pilot study suggests an interplay between HPV, vaginal microbiota and host defense may play a role in cervical cancer health disparity among NA women. Future longitudinal studies are ongoing to determine the mechanistic role of vaginal microbiota in HPV persistence, toward the long-term goal of reducing health disparities between White and NA populations. Citation Format: Pawel Laniewski, Tawnjerae R. Joe, Tristen L. Eddie, Skyler J. Bordeaux, Verity Quiroz, Donna J. Peace, J. Gregory Caporaso, Naomi R. Lee, Melissa M. Herbst-Kralovetz. Viewing Native American cervical cancer disparities through the lens of the vaginal microbiome: A pilot study [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr PR016.

New insights into the genetic predisposition of brucellosis and its effect on the gut and vaginal microbiota in goats

Goats contribute significantly to the global food security and industry. They constitute a main supplier of meat and milk for large proportions of people in Egypt and worldwide. Brucellosis is a zoonotic infectious disease that causes a significant economic loss in animal production. A case–control genome-wide association analysis (GWAS) was conducted using the infectious status of the animal as a phenotype. The does that showed abortion during the last third period of pregnancy and which were positive to both rose bengal plate and serum tube agglutination tests, were considered as cases. Otherwise, they were considered as controls. All animals were genotyped using the Illumina 65KSNP BeadChip. Additionally, the diversity and composition of vaginal and fecal microbiota in cases and controls were investigated using PCR-amplicone sequencing of the V4 region of 16S rDNA. After applying quality control criteria, 35,818 markers and 66 does were available for the GWAS test. The GWAS revealed a significantly associated SNP (P = 5.01 × 10–7) located on Caprine chromosome 15 at 29 megabases. Four other markers surpassed the proposed threshold (P = 2.5 × 10–5). Additionally, fourteen genomic regions accounted for more than 0.1% of the variance explained by all genome windows. Corresponding markers were located within or in close vicinity to several candidate genes, such as ARRB1, RELT, ATG16L2, IGSF21, UBR4, ULK1, DCN, MAPB1, NAIP, CD26, IFIH1, NDFIP2, DOK4, MAF, IL2RB, USP18, ARID5A, ZAP70, CNTN5, PIK3AP1, DNTT, BLNK, and NHLRC3. These genes play important roles in the regulation of immune responses to the infections through several biological pathways. Similar vaginal bacterial community was observed in both cases and controls while the fecal bacterial composition and diversity differed between the groups (P < 0.05). Faeces from the control does showed a higher relative abundance of the phylum Bacteroidota compared to cases (P < 0.05), while the latter showed more Firmicutes, Spirochaetota, Planctomycetota, and Proteobacteria. On the genus level, the control does exhibited higher abundances of Rikenellaceae RC9 gut group and Christensenellaceae R-7 group (P < 0.05), while the infected does revealed higher Bacteroides, Alistipes, and Prevotellaceae UCG-003 (P < 0.05). This information increases our understanding of the genetics of the susceptibility to Brucella in goats and may be useful in breeding programs and selection schemes that aim at controlling the disease in livestock.

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

BackgroundPrecancerous 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.MethodsUtilizing 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).ResultsAs 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.ConclusionPatients 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 Dynamic Changes in the Composition and Diversity of Vaginal Microbiota in Women of Different Pregnancy Periods.

The vaginal microbiota undergoes subtle changes during pregnancy, which may affect different pregnancy responses. This study used the Illumina MiSeq high-throughput sequencing method to analyze the 16S rRNA gene amplicons of pregnant women and the vaginal microbiota structure of pregnant women at different pregnancy periods. There were a total of 15 pregnant women, with 45 samples were taken from these women, within half a year before becoming pregnant, in the last trimester, and 42 days postpartum. Before and after pregnancy, the female vaginal microbiota was mainly composed of Firmicutes, followed by Actinobacteriota and Proteobacteria. The abundance of Lactobacillus was relatively high. The α-diversity and microbial abundance were relatively low, and there was no significant difference in microbial composition between the two. After childbirth, the diversity and abundance of women's vaginal bacterial communities were higher, with a decrease in the number of Firmicutes and a higher abundance of Actinobacteria, Proteobacteria, and Bacteroidota. There was a significant difference in the microbial community structure before and after pregnancy. This study showed that the microbiota structure of the vagina of pregnant women was similar to before pregnancy, but after childbirth, there were significant changes in the microbiota of the vagina, with a decrease in the number of probiotics and an increase in the number of harmful bacteria, increasing the risk of illness.

Gonorrhoeae must Compete with the Naturally Inhabitant of Microbial Community Right at the Outer Mucosal Surface to Authorize Infection

Aim: to describe the competition between Neisseria gonorrhoeae with the naturally inhabitant of microbial community right at the outer mucosal surface to authorize infection.&#x0D; Discussion: Gonorrhea is a sexually transmitted infection (STI) caused by the bacterium N. gonorrhea. Official report mention that by the year 2020, there were an estimated 82.4 million new infections among adults globally and poses a risk of onward transmission to sex partners. It surely could affect both men and women; for male, the symptoms are more obvious, but for women it occurs more often without prominent clinical symptoms and usually lead to long-term health problems including pelvic inflammatory disease and infertility. The female reproductive tract with its abundant variety of epithelial cells act as its primary niche where initially it was inhabited by normal microbiota, characterized by a high abundance of Lactobacilli, and uniquely linked to the host’s mucosal immunity and plays a critical role in the regulation of genital inflammation. Unfortunately, the dynamics regarding number and composition of vaginal microbiota has been shown to fluctuate over several internal and external factors, especially due to STI like gonorrhea. Its proposed evolution from an ancestral commensal bacterium, N. gonorrhoeae has retained features that are commonly found among commensal inhabitants, but it has also developed unique features that are crucial to its pathogenesis. The scope of its pathogenesis field elucidate competition, colonization and growth properties as main virulence determinants.&#x0D; Conclusion: Competition between N. gonorrhoeae and the already exist natural microbiota of the vagina occur initially at the mucosal surface. This gonococcus has several intrinsic factors that can facilitate its competitiveness including adherence, even though not all available adhesion mechanisms are actually used by this organism during the course of infection/colonization of any specific site.

ANALYSIS OF T-CELL IMMUNITY IN WOMEN WITH VAGINAL MICROBIOTA DISORDERS UNDER COMPLEX TREATMENT

Introduction. Immunological aspects of vaginal microbiota encompass the state of humoral and cellular immunity, which serves the primary function of nonspecific immune system stimulation. Therefore, alterations in its species composition lead to numerous disruptions in both cellular and humoral immune responses. The aim of the study – to investigate the parameters of T-cell immunity in women of reproductive age with vaginal microbiota disorders. Research Methods. We examined 115 women of reproductive age with vaginal microbiota disorders. To treat bacterial vaginosis in the third group of women according to the “Anomalous Vulvovaginal Discharge” treatment protocol, we selected the antibiotic metronidazole. In the second group with an intermediate type of vaginal microbiota, probiotics containing live Lactobacillus casei IMB B-7280 strains in the form of capsules and suppositories were used to normalize the species composition. After applying comprehensive therapy, we assessed the indicators of T-cell immunity in the study groups before treatment and one month after treatment. Results and Discussion. When studying T-cell immunity in women of reproductive age with vaginal microbiota disorders, no statistically significant changes in the levels of T-cells (CD3+, CD19-), T-helpers (CD4+, CD8-), and T-suppressors/T-cytotoxic cells (CD4-, CD8+) were found within the reference norms. However, statistically significant differences in T-suppressors/T-cytotoxic cells (CD4-, CD8+) were observed before treatment depending on the study groups. The lowest statistically significant level of these cells was found in the group of women with bacterial vaginosis, but the indicators of this immune branch tended to increase compared to the control group after complex treatment. After probiotic therapy, there was a tendency to increase T-helpers (CD4+, CD8-) in women with an intermediate type of vaginal microbiota. Conclusions. In conclusion, the analysis of the studied parameters of cellular immunity in women with vaginal microbiota disorders revealed a statistically significant decrease in T-suppressors/T-cytotoxic cells (CD4-, CD8+), which deepened as the vaginal microbiota disorder progressed. This indicates the influence of the species composition of vaginal microbiota on the T-suppressor/T-cytotoxic cellular immune branch.

Longitudinal analysis of vaginal microbiota during IVF fresh embryo transfer and in early pregnancy.

Non-Lactobacillus-dominated vaginal microbiota has been associated with poor gynecologic health and complications during pregnancy. Lactobacilli and especially Lactobacillus crispatus associate with good reproductive health and dominate the microbiota during healthy pregnancy. We examined whether the composition of vaginal microbiota at the time of fresh embryo transfer (ET) has an impact on the success of in vitro fertilization (IVF) and whether vaginal microbiota changes from IVF-ET to early pregnancy within individuals. Vaginal swab samples were collected from subfertile women at the time of IVF-ET (n = 76) and at the eighth gestational week (n = 21) from those who achieved clinical pregnancy. The microbiota composition was analyzed using 16S rRNA gene amplicon sequencing. L. crispatus was more abundant among the 30 women who achieved clinical pregnancy (46.9% vs. 19.1%, q = 0.039) and the 26 women who had live birth (43.3% vs. 23.1%, q = 0.32) compared to those who did not. Lactobacilli, mainly L. crispatus (76.2%), dominated all early pregnancy samples. Microbiota remained the same, i.e., Lactobacillus-dominated type in 52% (11/21), shifted from one Lactobacillus-dominated type to another in 24% (5/21), or shifted from mixed community to Lactobacillus-dominated type in 24% (5/21) women, but never from Lactobacillus dominance to non-lactobacilli dominance. Our results emphasize the role of L. crispatus in the success of IVF-ET and in early pregnancy. During pregnancy, the microbiota shifted toward L. crispatus dominance even if it was undetectable before pregnancy, indicating that most women hold a reservoir of this beneficial Lactobacillus in their reproductive tract.IMPORTANCEInfertility is a global public health issue which leads many couples to seek fertility treatments, of which in vitro fertilization (IVF) is considered to be the most effective. Still, only about one-third of the women achieve live birth after the first IVF embryo transfer (IVF-ET). Factors affecting embryo implantation are poorly known, but the female reproductive tract microbiota may play a key role. Our study confirms the beneficial role of vaginal lactobacilli, especially Lactobacillus crispatus, in the probability of achieving clinical pregnancy and live birth following IVF-ET. Our findings regarding the intra-individual shift of vaginal microbiota between non-pregnancy and pregnancy states are novel and provide new information about the dynamics of microbiota in the early steps of human reproduction. These findings may help clinicians in their attempts to optimize the conditions for ET by microbiota screening or modulation and timing the ET when the microbiota is the most favorable.

Vaginal Microbiota Profile in first-trimester miscarriages cases.

Due to its rising prevalence, first-trimester miscarriage is getting more attention. Abortion etiology and pathology, especially in non-pathological cases, are unknown. In this study, 435 vaginal swabs were collected from aborted women in Maternity Teaching Hospitals in Erbil and Shahid Dr. Khalid Hospital in Koya. We characterized the vaginal microbiota diversity and composition in first-trimester abortion and investigated the association between bacterial vaginosis and abortion before 12 weeks. Cultural, morphological, and biochemical characteristics for each bacterial genus were discovered, and VITEK-2 system was used to identify isolated bacteria. Samples from each type of bacteria were selected for sequencing utilizing 16 rRNA genes examining V4-V8 region for bacterial profiles. Bacterial vaginitis was found in 412 (94.7%) first-trimester miscarriages. Six Gram-positive and four Gram-negative bacteria were found in these 412 samples. Microorganism distribution varied Gram-positive bacteria Staphylococcus aureus (86) 20.87%, Enterococcus faecalis (31) 7.52%, Gardnerella vaginalis (24) 5.83%, Streptococcus agalactia (21) 5.1%, Lactobacillus equicursoris (14) 3.4% and Staphylococcus haemolyticus (12) 2.91%. Gram-negative bacteria including E. coli (107) 25.97%, Klebsiella pneumonia (76) 18.45%, Pseudomonas aeruginosa (29) 7.04% and Proteus mirabilis (12) 2.91%. Staphylococcus aureus had the highest rate of isolation at (86) 20.87%, while Lactobacillus equicursoris had the lowest rate at (14) 3.4%. Overall, the rate of isolation for Gram-negative bacteria (224) was 54.4%, while the rate for Gram-positive bacteria (188) was 45.6%.

Vaginal microbiome, antiretroviral concentrations, and HIV genital shedding in the setting of hormonal contraception initiation in Malawi.

The aim of this study was to understand how vaginal microbiota composition affects antiretroviral concentrations in the setting of hormonal contraception initiation. Cervicovaginal fluid (CVF) concentrations of tenofovir, lamivudine, and efavirenz from 73 Malawian women with HIV were compared before and after initiation of depot-medroxyprogesterone acetate (DMPA) or levonorgestrel implant. We evaluated antiretroviral concentrations and vaginal microbiota composition/structure in the context of contraception initiation and predicted genital shedding using multivariable repeated measurements models fit by generalized estimating equations. Mean lamivudine CVF concentrations decreased 37% 1 month after contraception initiation. Subgroup analyses revealed a 41% decrease in women 1 month after initiating levonorgestrel implant, but no significant difference was observed in DMPA group alone. Tenofovir, lamivudine, and efavirenz CVF concentrations were positively correlated with anaerobic bacteria associated with nonoptimal vaginal microbiota. Risk of genital HIV shedding was not significantly associated with tenofovir or lamivudine CVF concentrations [tenofovir relative risk (RR): 0.098, P = 0.75; lamivudine RR: 0.142, P = 0.54]. Lack of association between genital HIV shedding and efavirenz CVF concentrations did not change when adjusting for vaginal microbiota composition and lamivudine/tenofovir CVF concentrations (RR: 1.33, P = 0.531). No effect of hormone initiation on genital shedding provides confidence that women with HIV on either DMPA or levonorgestrel implant contraception will not have compromised ART efficacy. The unexpected positive correlation between antiretroviral CVF concentrations and certain bacterial taxa relative abundance requires further work to understand the mechanism and clinical relevance.

Prevotella and Gardnerella Are Associated With Treatment Failure Following First-line Antibiotics for Bacterial Vaginosis.

Bacterial vaginosis (BV) is a common vaginal dysbiosis that often recurs following first-line antibiotics. We investigated if vaginal microbiota composition was associated with BV recurrence. We analyzed samples and data from 121 women who participated in 3 published trials evaluating novel interventions for improving BV cure, including concurrent antibiotic treatment of regular sexual partners (RSPs). Women diagnosed with BV received first-line antibiotics and self-collected vaginal swabs pretreatment and the day after finishing antibiotics (immediately posttreatment). 16S rRNA gene sequencing was performed on vaginal samples. Logistic regression explored associations between BV recurrence and features of the vaginal microbiota pre- and posttreatment. Sixteen women (13% [95% confidence interval {CI}, 8%-21%]) experienced BV recurrence within 1 month of treatment. Women with an untreated RSP were more likely to experience recurrence than women with no RSP (P = .008) or an RSP who received treatment (P = .011). A higher abundance of Prevotella pretreatment (adjusted odds ratio [AOR], 1.35 [95% CI, 1.05-1.91]) and Gardnerella immediately posttreatment (AOR, 1.23 [95% CI, 1.03-1.49]) were associated with increased odds of BV recurrence. Having specific Prevotella spp prior to recommended treatment and persistence of Gardnerella immediately posttreatment may contribute to the high rates of BV recurrence. Interventions that target these taxa are likely required to achieve sustained BV cure.

The microbiota of pregnant women with SARS-CoV-2 and their infants

BackgroundInfants receive their first bacteria from their birthing parent. This newly acquired microbiome plays a pivotal role in developing a robust immune system, the cornerstone of long-term health.ResultsWe demonstrated that the gut, vaginal, and oral microbial diversity of pregnant women with SARS-CoV-2 infection is reduced, and women with early infections exhibit a different vaginal microbiota composition at the time of delivery compared to their healthy control counterparts. Accordingly, a low relative abundance of two Streptococcus sequence variants (SV) was predictive of infants born to pregnant women with SARS-CoV-2 infection.ConclusionsOur data suggest that SARS-CoV-2 infections during pregnancy, particularly early infections, are associated with lasting changes in the microbiome of pregnant women, compromising the initial microbial seed of their infant. Our results highlight the importance of further exploring the impact of SARS-CoV-2 on the infant’s microbiome-dependent immune programming.1tBoQ_Pk5FCyiTEw6F72J3Video

O-258 Characterization of vaginal microbiota during IVF fresh embryo transfer (IVF-ET) and in early pregnancy

Abstract Study question Does the composition of vaginal microbiota affect the success of IVF-ET? Does vaginal microbiota profile change intra-individually from IVF-ET to early pregnancy? Summary answer L. crispatus is associated with successful IVF outcome. The individual composition of vaginal microbiota tends to shift towards Lactobacillus-dominance between IVF-ET and early pregnancy. What is known already Lactobacilli are the most abundant species in healthy female reproductive tract microbiota and especially Lactobacillus crispatus is associated with good gynecological health. The composition of vaginal microbiota may also play an important role in infertility and the success of IVF. Women with Lactobacillus-dominated vaginal microbiota may have higher pregnancy rates after IVF-ET compared to women with non-Lactobacillus dominance, but the results have been controversial. In healthy pregnancy, vaginal microbiota is usually lactobacilli-dominated, whereas miscarriages are associated to a non-lactobacillus dominance. The intra-individual shift on the vaginal microbiota from ET to early pregnancy has not been studied earlier. Study design, size, duration This observational and longitudinal study investigates the effect of vaginal microbiota on the success of fresh IVF-ET. Another aim was to study the intra-individual changes in the microbiota profile between IVF-ET and early pregnancy. We recruited 76 subfertile women undergoing IVF with their own gametes between November 2019 and September 2021 in the Reproductive Medicine Unit, Helsinki University Hospital and in Oulu University Hospital. Main outcomes were clinical pregnancy and live birth. Participants/materials, setting, methods Study population composed of 76 subfertile women under 40 years of age. One IVF cycle including fresh embryo transfer was studied. Vaginal swabs were taken at the time of IVF-ET and at 8th gestational week. Samples were frozen in − 20 °C and moved to − 80 °C within four weeks. Microbiota analysis was performed with next-generation sequencing of 16S rRNA gene using Illumina MiSeq technology. Clinical data were collected from the patient registries and background questionnaires. Main results and the role of chance Altogether 30 (39.5%) of the 76 women achieved pregnancy after IVF-ET and 26 (34.2%) had live birth. The relative abundance of L. crispatus among women who achieved clinical pregnancy (46.9% vs. 19.1%, q = 0.003) and live birth (43.3% vs. 19.1%, q = 0.006) was significantly higher compared to women who did not. After adjusting for age, parity and gravidity, the results remained similar when comparing clinical pregnancy (q = 0.039), but in live birth, the difference lost significance (q = 0.14) Vaginal samples were taken at the 8th gestational week from 21 of 30 women who got pregnant. All samples were dominated by Lactobacillus species, mainly by L. crispatus (n = 16, 76.2%). Only two (9.2%) women had L. iners dominated microbiota at the early pregnancy. When comparing samples taken during fresh IVF-ET and early pregnancy, L. crispatus had significantly higher relative abundance in early pregnancy samples compared to the samples taken at the ET (71.5% vs. 43.4%, q = 0.001), whereas the relative abundance of L. iners (10.1% vs. 24.1%, q = 0.004), and G. vaginalis (0.8% vs. 14.7%, q = 0.004) decreased. Altogether 13 women had an intra-individual shift in their microbiota profiles. Limitations, reasons for caution The small sample size was the main limitation of our study. Larger studies are needed to confirm our findings and their relationship with the success of IVF-ET. Wider implications of the findings Vaginal microbiota at the time of fresh IVF-ET has an impact of the success of IVF treatment. Also, the intra-individual composition of vaginal microbiota between IVF-ET and early pregnancy changes in some women. The vaginal microbiota modification through probiotics in order to optimize the result of IVF warrants more studies. Trial registration number Not applicable

P-672 Vaginal microbiome changes in women with polycystic ovary syndrome: a large cross-sectional study

Abstract Study question How the vaginal microbiome changes in women with polycystic ovary syndrome? Summary answer The PCOS women had a higher diversity in the vaginal microbiome and showed an enhanced level of heterogeneity. What is known already PCOS is a common reproductive endocrine disorder with a highly heterogeneous clinical presentation. Recently, few studies with limited sample size have reported that the inconsistent vaginal microbiota composition changes in PCOS. Study design, size, duration The cross-sectional study conducted at a single academic university-affiliated center. A total of 1,446 subjects, including 713 PCOS cases and 733 controls, were recruited. Participants/materials, setting, methods Vaginal swabs were collected for subsequent 16S rRNA gene sequencing. The microbiome diversities, community distances, vaginal bacterial relative abundances, and microbial interactions network were compared between the PCOS group and control group. Main results and the role of chance The PCOS group had a higher alpha diversity in the vaginal microbiome than the control (P &amp;lt; 0.05), while higher intra-group variability was observed in PCOS (P &amp;lt; 0.05). At the genus level, the abundance of Lactobacillus in the PCOS group decreased, while the abundance of Gardnerella and Ureaplasma increased (FDR&amp;lt;0.2). Gardnerella vaginalis, Prevotella buccalis, and Prevotella timonensis were identified as differential species and were significantly associated with clinical parameters of PCOS, like AMH. The microbial interaction network analysis revealed that Prevotella and Lactobacillus could be key drivers for network rewiring in PCOS. Notable alterations of predicted pathways, which significantly differed between PCOS and control women, mainly enriched in amino acid metabolism. Limitations, reasons for caution The study only included Chinese Han population data. Due to the structure of the vaginal flora may vary between ethnic groups, generalizing the results of this study to other populations should be taken caution. Wider implications of the findings This study with large samples could enhance our understanding of the PCOS vaginal microbiome, and provide a basis for future research on the potential mechanism by which pathogenic bacteria are involved in PCOS vaginal microbial imbalances. Trial registration number Not applicable

Vaginal and Cervical Microbiota Composition in Patients with Endometrial Cancer.

According to recent data, changes in the vaginal microbiota could affect the risk of gynaecological cancers. Women suffering from endometrial cancer present significant changes in cervicovaginal microbiota composition. The objective of our study was to characterize the cervicovaginal microbiota of women undergoing hysterectomy due to benign disease, atypical hyperplasia, and endometrial cancer; The study included 96 patients, who undergone surgical treatment due to benign uterine disease, precancerous endometrial lesion, and endometrial cancer. Quantitative and qualitative real-time PCR analysis of DNA isolated from vaginal fornix and endocervical canal samples was performed to detect the 19 most commonly identified microorganisms, including different Lactobacillus spp., Atopobium, Bifidobacterium, Chlamydia, and Gardnerella; At least one of the tested microorganisms was identified in 88.5% of vaginal and 83.3% of cervical samples. Lactobacillus iners was significantly more frequent in patients with benign condition, whereas Dialister pneumosintes and Mobiluncus curtisii was more frequent in cancer patients; Mobiluncus curtisi and Dialister pneumosintes, which were identified as significantly more common in endometrial cancer vaginal samples, may be considered as potential endometrial cancer co-factors which promote/stimulate carcinogenesis. However, the exact mechanism of such activity remains unexplained and requires further investigations.

Association between monoaromatic hydrocarbons exposure and vaginal microbiota disorder in recurrent implantation failure

Recurrent implantation failure (RIF) is a significant challenge facing population development, with the impact of monoaromatic hydrocarbons (MACHs) exposure on embryo implantation and reproductive hazards remaining largely unclear. As such, we conducted a prospective randomized controlled cohort study to explore the potential correlations between exposure to MACHs and vaginal microbiota, and their potential adverse effects on embryo implantation. Our findings suggest that exposure to Mono(2-ethylhexyl) phthalate (MEHP), Methyl N-methylanthranilate, and Benzene is closely linked with the disruption of the microbial community in the RIF group. The RIF group thus exhibited a fragile vaginal microbial community structure, with lower lactic acid bacterial abundance, and higher potential pathogenic bacterial abundance, such as Streptococcus anginosus and Peptoniphilus asaccharolyticus. This abnormal vaginal microbiota composition was associated with adverse pregnancy outcomes, with sphingolipid metabolism dysfunction being a key factor in abnormal microbiota leading to such outcomes. Additionally, we found that exposure to Methyl N-methylanthranilate and MEHP was closely associated with decreased abundance of Lactobacillus (including L.crispatus and L.jensenii) and diminished reproductive tract protective barrier function. Our study underscores the significance of acknowledging the impact of MACHs, a ubiquitous everyday exposure, on female fertility.

Local Immune Biomarker Expression Depending on the Uterine Microbiota in Patients with Idiopathic Infertility.

The endometrium has traditionally been considered sterile. Nowadays, active studies are performed on the female upper genital tract microbiota. Bacteria and/or viruses colonizing the endometrium are known to alter its functional properties, including receptivity and embryo implantation. Uterine cavity inflammation caused by microorganisms leads to disrupted cytokine expression, which, in turn, is mandatory for the successful implantation of the embryo. The present study assessed the vaginal and endometrial microbiota composition and its relation to the levels of cytokines produced by the endometrium in reproductive-aged women complaining of secondary infertility of unknown origin. The multiplex real-time PCR assay was applied for vaginal and endometrial microbiota analysis. The quantitative measurement of endometrial α-defensin (DEFa1), transforming growth factor (TGFβ1), and basic fibroblast growth factor (bFGF2) was carried out using the ELISA (Cloud-Clone Corporation (Katy, TX, USA; manufactured in Wuhan, China). A reliable decline in endometrial TGFβ1 and bFGF2 and an increase in DEFa1 were demonstrated in women with idiopathic infertility when compared to fertile patients. However, TGFβ1, bFGF2, and DEFa1 expression correlated reliably only with the presence of Peptostreptococcus spp. and HPV in the uterine cavity. The obtained results highlight the importance of local immune biomarker determination in the assessment of certain bacteria and viruses' significance as causative agents of infertility.

Vaginal microbiota of adolescents and their mothers: A preliminary study of vertical transmission and persistence

IntroductionFactors that influence vaginal microbiota composition, including its source, are not well understood.MethodsTo determine if vaginal microbiota transmission from mother to daughter at birth could possibly influence the human vaginal microbiota composition in adolescence, we conducted a preliminary study to investigate the relationship between the vaginal microbiota of 13 adolescents (ages 15-21) and their mothers and the daughter’s birth mode.Results and discussionBased on analysis of bacterial 16S rRNA gene sequences, the vaginal microbiotas of mother/daughter pairs were more similar to each other if the daughter was born by vaginal delivery rather than by C-section. Specifically, within pair β-diversity, measured by the Yue and Clayton θ (θYC) distance metric, was significantly lower if the daughter was born by vaginal delivery. Additionally, genome sequences from an important member of the vaginal microbiota, Lactobacillus crispatus, isolated from one mother/daughter pair in which the daughter was born by vaginal delivery, were highly similar based on recombination-filtered single nucleotide polymorphisms (SNPs). Both community-level analysis and isolate genome sequence analysis are consistent with birth-mode dependent transmission and persistence of at least some members of the vaginal microbiota.