The composition and stability of the vaginal microbiota of normal pregnant women is different from that of non-pregnant women

16S rRNA female reproductive microbiome investigation reveals Dalfopristin, Clorgyline, and Hydrazine as potential therapeutics for the treatment of bacterial vaginosis

Bacterial vaginosis (BV) is a prevalent vaginal illness resulting from a disruption in the vaginal microbial equilibrium. The vaginal microbiota has been shown to have a substantial impact on the development and continuation of BV. This work utilized 16S rRNA sequence analysis of vaginal microbiome samples (Control vs BV samples) utilizing Parallel-Meta 3 to investigate the variations in microbial composition. The unique genes identified were used to determine prospective therapeutic targets and their corresponding inhibitory ligands. Further, molecular docking was conducted and then MD simulations were carried out to confirm the docking outcomes. In the BV samples, we detected several anaerobic bacteria recognized for their ability to generate biofilms, namely Acetohalobium, Anaerolineaceae, Desulfobacteraceae, and others. Furthermore, we identified Dalfopristin, Clorgyline, and Hydrazine as potential therapeutic options for the management of BV. This research provides new insights into the causes of BV and shows the potential effectiveness of novel pharmacological treatments.

Temporal composition of the cervicovaginal microbiome associates with hrHPV infection outcomes in a longitudinal study

BACKGROUND

Persistent infections with high-risk human papillomavirus (hrHPV) can cause cervical squamous intraepithelial lesions (SIL) that may progress to cancer. The cervicovaginal microbiome (CVM) correlates with SIL, but the temporal composition of the CVM after hrHPV infections has not been fully clarified.

METHODS

To determine the association between the CVM composition and infection outcome, we applied high-resolution microbiome profiling using the circular probe-based RNA sequencing technology on a longitudinal cohort of cervical smears obtained from 141 hrHPV DNA-positive women with normal cytology at first visit, of whom 51 were diagnosed by cytology with SIL six months later.

RESULTS

Here we show that women with a microbial community characterized by low diversity and high Lactobacillus crispatus abundance at both visits exhibit low risk to SIL development, while women with a microbial community characterized by high diversity and Lactobacillus depletion at first visit have a higher risk of developing SIL. At the level of individual species, we observed that a high abundance for Gardnerella vaginalis and Atopobium vaginae at both visits associate with SIL outcomes. These species together with Dialister micraerophilus showed a moderate discriminatory power for hrHPV infection progression.

CONCLUSIONS

Our results suggest that the CVM can potentially be used as a biomarker for cervical disease and SIL development after hrHPV infection diagnosis with implications on cervical cancer prevention strategies and treatment of SIL.

Longitudinal profiles of the vaginal microbiota of pre-, peri-, and postmenopausal women: preliminary insights from a secondary data analysis

OBJECTIVE

Menopause is often accompanied by lowered Lactobacillus spp. relative abundance and increased abundance of diverse anaerobic/aerobic bacteria in the vaginal microbiota due in part to declines in estrogen. These microbiota are associated with urogenital symptoms and infections. In premenopause, vaginal microbiota can fluctuate rapidly, particularly with menstrual cycles and sexual activity; however, the longitudinal dynamics of vaginal microbiota are understudied in peri- and postmenopause. We described vaginal community stability across reproductive stages.

METHODS

Pre- (n = 83), peri- (n = 8), and postmenopausal (n = 11) participants provided twice-weekly mid-vaginal samples (total, 1,556; average, 15 per participant) over 8 weeks in an observational study. Composition of the vaginal microbiota was characterized by 16S rRNA gene amplicon sequencing, and a community state type (CST) was assigned to each sample. Clustering of longitudinal CST profiles, CST transition rates, duration of low-Lactobacillus/high bacterial diversity CSTs, and other metrics of bacterial community dynamics were assessed across reproductive stages.

RESULTS

The proportion of participants with longitudinal CST profiles characterized by low-Lactobacillus CSTs was similar among pre- (38.6%), peri- (37.5%), and postmenopausal (36.4%) participants (P = 0.69). CST transition rates between consecutive samples were 21.1%, 16.7%, and 14.6% for pre-, peri-, and postmenopausal participants, respectively (P = 0.49). Low-Lactobacillus CST tended to persist for at least 4 weeks, irrespective of reproductive stage.

CONCLUSIONS

Findings from this small yet frequently sampled cohort revealed vaginal bacterial fluctuations over 8 weeks that were similar across reproductive stages. Larger and longer-term studies based on these preliminary data could provide insights into the influence of microbiota dynamics on urogenital outcomes during menopause.

Host factors are associated with vaginal microbiome structure in pregnancy in the ECHO Cohort Consortium

Using pooled vaginal microbiota data from pregnancy cohorts (N = 683 participants) in the Environmental influences on Child Health Outcomes (ECHO) Program, we analyzed 16S rRNA gene amplicon sequences to identify clinical and demographic host factors that associate with vaginal microbiota structure in pregnancy both within and across diverse cohorts. Using PERMANOVA models, we assessed factors associated with vaginal community structure in pregnancy, examined whether host factors were conserved across populations, and tested the independent and combined effects of host factors on vaginal community state types (CSTs) using multinomial logistic regression models. Demographic and social factors explained a larger amount of variation in the vaginal microbiome in pregnancy than clinical factors. After adjustment, lower education, rather than self-identified race, remained a robust predictor of L. iners dominant (CST III) and diverse (CST IV) (OR = 8.44, 95% CI = 4.06-17.6 and OR = 4.18, 95% CI = 1.88-9.26, respectively). In random forest models, we identified specific taxonomic features of host factors, particularly urogenital pathogens associated with pregnancy complications (Aerococcus christensenii and Gardnerella spp.) among other facultative anaerobes and key markers of community instability (L. iners). Sociodemographic factors were robustly associated with vaginal microbiota structure in pregnancy and should be considered as sources of variation in human microbiome studies.

Cervicovaginal Microbial-Immune State and Group B Streptococcus Colonization in Pregnancy

OBJECTIVE

 Maternal colonization with Group B Streptococcus (GBS) is a significant risk factor for serious neonatal morbidity. There are limited data on how the cervicovaginal (CV) microbiota and host immune factor β-defensin-2 might influence GBS colonization in pregnant individuals. This study sought to determine if the CV microbiota is associated with GBS colonization in pregnant individuals, and if β-defensin-2 modifies this relationship.

STUDY DESIGN

 This was a secondary analysis of a prospective cohort study of pregnant individuals with singleton pregnancies who had CV microbiota specimens analyzed at 16 to 20, 20 to 24, and 24 to 28 weeks' gestation, along with a third trimester GBS rectovaginal (RV) culture (n = 492). Microbiota data were analyzed with 16S rRNA gene sequencing and classified into community state types (CSTs). Log-binomial multivariable regression was used to model associations between CST and GBS RV status and to calculate risk ratios. β-defensin-2, an immune factor known to modulate the relationship between CST and pregnancy outcomes, was examined as an effect modifier.

RESULTS

 Of 492 individuals, 34.3% were GBS RV + . Compared with individuals with CST I at 16 to 20 weeks, individuals with CST IV-A and CST II had a significantly elevated relative risk of subsequent GBS RV+ status. When stratified by high and low β-defensin-2 levels, β-defensin-2 was found to be an effect modifier of the association between CST IV-A and GBS RV+ status. In individuals with low β-defensin-2 levels, CST VI-A was associated with GBS RV+ status, but among individuals with high β-defensin-2 levels, there was no such association (interaction p-value = 0.03).

CONCLUSION

 Pregnant individuals with CV microbiota characterized by CST IV-A and CST II had significantly elevated risk of GBS RV colonization in the third trimester compared with those with CST I, and β-defensin-2 was an effect modifier of the association between CST IV-A and GBS RV+ status. Future research should investigate if manipulation of the CV microbiota can prevent GBS colonization, thereby reducing intrapartum antibiotic prophylaxis and the risks of neonatal GBS infection.

KEY POINTS

· The relationship between the CV microbiota and GBS RV colonization is unknown.. · A Lactobacillus-deficient, anaerobic rich vaginal community, CST IV-A, is associated with increased risk of GBS RV colonization.. · β-defensin-2 is an effect modifier of the association between CST IV-A and GBS RV+ status..

Cervicovaginal microbiota: a promising direction for prevention and treatment in cervical cancer

Cervical cancer is a common malignancy in women, with high incidence rate and mortality. Persistent infection of high-risk human papillomavirus (HPV) is the most important risk factor for cervical cancer and precancerous lesions. Cervicovaginal microbiota (CVM) plays an essential role in the defense of HPV infections and prevention of subsequent lesions. Dominance of Lactobacillus is the key of CVM homeostasis, which can be regulated by host, exogenous and endogenous factors. Dysbiosis of CVM, including altered microbial, metabolic, and immune signatures, can contribute to persist HPV infection, leading to cervical cancer. However, there is no evidence of the causality between CVM and cervical cancer, and the underlying mechanism remains unexplored. Considering the close correlation between CVM dysbiosis and persistent HPV infection, this review will overview CVM, its role in cervical cancer development and related mechanisms, and the prospects for therapeutic applications.

Affective Symptoms in Pregnancy are Associated with the Vaginal Microbiome

Composition of the vaginal microbiome in pregnancy is associated with adverse maternal, obstetric, and child health outcomes. Identifying the sources of individual differences in the vaginal microbiome is therefore of considerable clinical and public health interest. The current study tested the hypothesis that vaginal microbiome composition during pregnancy is associated with an individual's experience of affective symptoms and stress exposure. Data were based on a prospective longitudinal study of a diverse and medically healthy community sample of 275 mother-infant pairs. Affective symptoms and stress exposure and select measures of associated biomarkers (diurnal salivary cortisol, serum measures of sex hormones) were collected at each trimester; self-report, clinical, and medical records were used to collect detailed data on socio-demographic factors and health behavior, including diet and sleep. Vaginal microbiome samples were collected in the third trimester (34-40 weeks) and characterized by 16S rRNA sequencing. Identified taxa were clustered into three community state types (CST1-3) based on dissimilarity of vaginal microbiota composition. Results indicate that depressive symptoms during pregnancy were reliably associated with individual taxa and CST3 in the third trimester. Prediction of functional potential from 16S taxonomy revealed a differential abundance of metabolic pathways in CST1-3 and individual taxa, including biosynthetic pathways for the neuroactive metabolites, serotonin and dopamine. With the exception of bioavailable testosterone, no significant associations were found between symptoms- and stress-related biomarkers and CSTs. Our results provide further evidence of how prenatal psychological distress during pregnancy alters the maternal-fetal microbiome ecosystem that may be important for understanding maternal and child health outcomes.

Vulvovaginitis in pregnant women

• The balanced vaginal microbiome is the main factor defending the vaginal environment against infections. Lactobacilli play a key role in this regard, maintaining the vaginal pH within the normal range (3.8 to 4.5). •Hormonal and immune adaptations resulting from pregnancy influence changes in the vaginal microbiome during pregnancy. •An altered vaginal microbiome predisposes to human immunodeficiency virus (HIV) infection. •Bacterial vaginosis is the main clinical expression of an imbalanced vaginal microbiome. •Vulvovaginal candidiasis depends more on the host's conditions than on the etiological agent. •Trichomonas vaginalis is a protozoan transmitted during sexual intercourse. •The use of probiotics is not approved for use in pregnant women.

Prevalence of Bacterial Vaginosis and Its Association With Preterm Birth in a Tertiary Care Hospital in Chennai: A Cross-Sectional Study

Background The most common preventive cause of premature labour is ascending infections. This study was conducted to evaluate the association between bacterial vaginosis (BV) and preterm labour in antenatal women and determine the significance of using the Amsel criteria to screen for BV. Methods This was a hospital-based cross-sectional study conducted among 100 antenatal mothers in the second trimester attending the antenatal OPD at a tertiary care hospital in Chennai from October 2019 to September 2021 after obtaining clearance from the institutional ethics committee and written informed consent from the study participants. Data were entered in Excel (Microsoft Corporation, Redmond, WA) and analysed in SPSS (IBM Corp., Armonk, NY). Results According to the Amsel criteria, BV was detected in 21 women (21%). Neither maternal age nor parity had an effect on the study group. There was a statistically significant relationship (p < 0.05) between the mode of delivery, preterm labour, and the study group. Of the 21 positive BV cases, 95% were positive for clue cells and only 5% were positive for gram-negative bacteria. Consequently, BV was found to be associated with early labour. There is no association between BMI and BV (p > 0.005). Conclusion In the current study, BV was shown to be associated with preterm labour. Our study underscores the significance of the Amsel criteria as a valuable tool for screening BV in antenatal women.

Antimicrobial Resistance Patterns in Patients with Vaginal Discharge: A 2019-2022 Analysis at the National Health Laboratory in Eritrea

Background

Antimicrobial resistance poses a significant global threat to the treatment of bacterial infections, particularly in low- and middle-income regions such as Africa. This study is aimed at analyzing antimicrobial resistance patterns in vaginal swab samples from patients at the National Health Laboratory from 2019 to 2022.

Methods

This retrospective study examined patient records from vaginal swab analyses performed at the National Health Laboratory between January 1, 2019, and December 31, 2022. Ethical approval was obtained from the Ministry of Health Research Ethical Approval and Clearance Committee on 15/02/2023.

Results

Of the 622 samples, 83% underwent microbial isolation and identification. Citrobacter spp. exhibited high resistance (>43%) to antibiotics such as cephalexin, ceftazidime, nalidixic acid, ampicillin, gentamicin, and tetracycline. E. coli showed resistance rates of more than 50% to ampicillin, trimethoprim-sulfamethoxazole, and tetracycline. Klebsiella spp. and Proteus spp. exhibited resistance rates that exceeded 47% to specific antibiotics. Gram-positive bacteria have resistance rates of more than 49% with ampicillin, trimethoprim-sulfamethoxazole, tetracycline, oxacillin, vancomycin, and penicillin G. In particular, S. aureus demonstrated no resistance to rifampicin or clindamycin, while Streptococcus spp. showed 100% resistance to rifampicin and vancomycin. Several species, including Proteus species, Streptococcus spp., S. aureus, and Klebsiella spp. exhibited multidrug resistance.

Conclusion

Most gram-negative bacteria displayed higher resistance of >45% to ampicillin, trimethoprim-sulfamethoxazole, and tetracycline. Among gram-positive bacteria, a higher resistance rate with ampicillin, trimethoprim-sulfamethoxazole, tetracycline, oxacillin, vancomycin, and penicillin G was recorded. S. aureus showed no resistance to rifampicin and clindamycin, and Strep. spp. indicated 100% resistance to rifampicin and vancomycin. This study highlights critical gaps and areas for further exploration. Expanding the spectrum of antibiotics tested and investigating underlying multidrug resistance mechanisms would provide a more comprehensive understanding of resistance patterns.

Interaction of microbiota, mucosal malignancies, and immunotherapy-Mechanistic insights

The microbiome has emerged as a crucial modulator of host-immune interactions and clearly impacts tumor development and therapy efficacy. The microbiome is a double-edged sword in cancer development and therapy as both pro-tumorigenic and anti-tumorigenic bacterial taxa have been identified. The staggering number of association-based studies in various tumor types has led to an enormous amount of data that makes it difficult to identify bacteria that promote tumor development or modulate therapy efficacy from bystander bacteria. Here we aim to comprehensively summarize the current knowledge of microbiome-host immunity interactions and cancer therapy in various mucosal tissues to find commonalities and thus identify potential functionally relevant bacterial taxa. Moreover, we also review recent studies identifying specific bacteria and mechanisms through which the microbiome modulates cancer development and therapy efficacy.

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

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

Stress and depression-associated shifts in gut microbiota: A pilot study of human pregnancy

Background

Psychosocial stress and mood-related disorders, such as depression, are prevalent and vulnerability to these conditions is heightened during pregnancy. Psychosocial stress induces consequences via several mechanisms including the gut microbiota-brain axis and associated signaling pathways. Previous preclinical work indicates that prenatal stress alters maternal gut microbial composition and impairs offspring development. Importantly, although the fecal and vaginal microenvironments undergo alterations across pregnancy, we lack consensus regarding which shifts are adaptive or maladaptive in the presence of prenatal stress and depression. Clinical studies interrogating these relationships have identified unique taxa but have been limited in study design.

Methods

We conducted a prospective cohort study of pregnant individuals consisting of repeated administration of psychometrics (Perceived Stress Scale (PSS) and Center for Epidemiological Studies Depression Scale (CES-D)) and collection of fecal and vaginal microbiome samples. Fecal and vaginal microbial community composition across psychometric responses were interrogated using full-length 16S rRNA sequencing followed by α and β-diversity metrics and taxonomic abundance.

Results

Early pregnancy stress was associated with increased abundance of fecal taxa not previously identified in related studies, and stress from late pregnancy through postpartum was associated with increased abundance of typical vaginal taxa and opportunistic pathogens in the fecal microenvironment. Additionally, in late pregnancy, maternal stress and depression scores were associated with each other and with elevated maternal C-C motif chemokine ligand 2 (CCL2) concentrations. At delivery, concordant with previous literature, umbilical CCL2 concentration was negatively correlated with relative abundance of maternal fecal Lactobacilli. Lastly, participants with more severe depressive symptoms experienced steeper decreases in prenatal vaginal α-diversity.

Conclusion

These findings a) underscore previous preclinical and clinical research demonstrating the effects of prenatal stress on maternal microbiome composition, b) suggest distinct biological pathways for the consequences of stress versus depression and c) extend the literature by identifying several taxa which may serve critical roles in mediating this relationship. Thus, further interrogation of the role of specific maternal microbial taxa in relation to psychosocial stress and its sequelae is warranted.

Draft genomes of Lactobacillus jensenii UMB0908, UMB1545, and UMB5777 from the urinary tract

Lactobacillus jensenii is a member of the female urogenital microbiome. Previous research has identified strains of L. jensenii that are capable of inhibiting or killing uropathogens, including E. coli. Here, we present the draft genomes of three L. jensenii strains collected from urine samples.

Microbial interactions among Gardnerella, Prevotella and Fannyhessea prior to incident bacterial vaginosis: protocol for a prospective, observational study

INTRODUCTION

The aetiology of bacterial vaginosis (BV), a biofilm-associated vaginal infection, remains unknown. Epidemiologic data suggest that it is sexually transmitted. BV is characterised by loss of lactic acid-producing lactobacilli and an increase in facultative and strict anaerobic bacteria. Gardnerella spp are present in 95%-100% of cases; Gardnerella vaginalis has been found to be more virulent than other BV-associated bacteria (BVAB) in vitro. However, G. vaginalis is found in women with normal vaginal microbiota and colonisation is not sufficient for BV development. We hypothesise that Gardnerella spp initiate BV biofilm formation, but incident BV (iBV) requires incorporation of other key BVAB (ie, Prevotella bivia, Fannyhessea vaginae) into the biofilm that alter the transcriptome of the polymicrobial consortium. This study will investigate the sequence of microbiologic events preceding iBV.

METHODS AND ANALYSIS

This study will enrol 150 women aged 18-45 years with normal vaginal microbiota and no sexually transmitted infections at a sexual health research clinic in Birmingham, Alabama. Women will self-collect twice daily vaginal specimens up to 60 days. A combination of 16S rRNA gene sequencing, qPCR for Gardnerella spp, P. bivia and F. vaginae, and broad range 16S rRNA gene qPCR will be performed on twice daily vaginal specimens from women with iBV (Nugent score 7-10 on at least 2 consecutive days) and controls (with comparable age, race, contraceptive method and menstrual cycle days) maintaining normal vaginal microbiota to investigate changes in the vaginal microbiota over time for women with iBV. Participants will complete daily diaries on multiple factors including sexual activity.

ETHICS AND DISSEMINATION

This protocol is approved by the University of Alabama at Birmingham Institutional Review Board (IRB-300004547) and written informed consent will be obtained from all participants. Findings will be presented at scientific conferences and published in peer-reviewed journals as well as disseminated to providers and patients in communities of interest.

Association Between Risk of Clostridium difficile Infection and Duration of Proton Pump Inhibitor or H2-Receptor Antagonist Use in Hospitalized Patients

INTRODUCTION

Limited studies have evaluated the association between Clostridium difficile infection (CDI) and the duration of proton pump inhibitor (PPI) or histamine H2-receptor blocker (H2RA) use and provided a cutoff duration for PPI or H2RA use to mitigate a substantially increased risk of CDI. We aimed to evaluate these associations in hospitalized patients using a nationwide insurance claims database.

METHODS

We conducted a nested case-control study to identify cases with a first ever record of CDI in a study cohort undergoing PPI or H2RA therapy from the National Health Insurance Database from 2012 to 2018. Each case was matched with one control by age, sex, and calendar year. We used conditional logistic regression to estimate the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC ROC). Youden's J statistic was used to identify the optimal cutoff duration in days for PPI or H2RA use.

RESULTS

In the main analysis, the AUC ROC was 0.64 (95% CI 0.63-0.66) and optimal cutoff duration was 15 days for PPI users. The AUC ROC was 0.63 (95% CI 0.62-0.64) and optimal cutoff duration was 16 days for H2RA users. In the sensitivity analyses, the results were similar to those of the main analysis, and the optimal cutoff duration was in the range of 14-15 days.

CONCLUSIONS

The optimal cutoff duration for PPI and H2RA use was about 2 weeks. It is necessary to be cautious regarding the risk of CDI in patients taking PPIs or H2RAs for longer than 2 weeks.

Description of the vaginal microbiota in nulliparous ewes during natural mating and pregnancy: preliminary signs of the male preputial microbiota modulation

The vaginal microbiota plays a key role in animals' health. Understanding its diversity and composition and associated changes occurring through the reproductive cycle represents valuable knowledge to disclose the mechanisms leading to dysbiosis and eventually to infection. Even if the human vaginal microbiota has been thoroughly studied, scarce research has been conducted on the vaginal microbiota of livestock. In this study, 16S rRNA gene-based sequencing was performed on vaginal samples of ten nulliparous ewes at three different sampling points: before the estrus synchronization protocol (T0), at the time of estrus before mating (Testrus), and the day of the pregnancy diagnosis (Tpreg). Preputial samples from the three males collected pre and post-mating were also analyzed. Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria were the most abundant phyla in vaginal samples. The most abundant genera were Porphyromonas, Anaerococcus, and Peptinophilius. Vaginal microbiota biodiversity decreased during pregnancy. Tenericutes (Ureaplasma spp.) increased significantly at Tpreg in both pregnant and non-pregnant ewes. Differences were observed between pregnant and non-pregnant ewes at Tpreg where pregnant ewes had a significantly higher abundance of Actinobacillus spp. and Ureaplasma spp. Ewes that were diagnosed with pregnancy at Tpreg showed a decreased abundance of gram-negative bacteria such as Bacteroidales, Campylobacterales, and Enterobacteriales. In addition, a significant decrease in the relative abundances of genera within Firmicutes, such as Alloicoccus (Lactobacillales), Atopostipes (Lactobacillales), and an uncultured bacteria W5053 from Family XI (Firmicutes, Clostridiales) was observed in non-pregnant ewes at Tpreg. The four most abundant phyla in the rams' prepuce were the same as in the ewes' vagina. The most abundant genus was Corynebacterium. No major differences were observed in the ram's preputial microbiota between pre and post-mating samples. Nevertheless, the differences in the taxonomic composition of ewes' vaginal microbiota between Testrus and Tpreg could be explained by the exposure to the preputial microbiota. This study offers new insights into the effects of several key steps of the ewe's reproductive cycle such as estrus-synchronization protocol, mating, and pregnancy on ovine vaginal microbiota. The knowledge of the microbiota dynamics during the reproductive cycle can help improve the reproductive outcomes of dams by identifying biomarkers and putative probiotics.

Microbiota dynamics, metabolic and immune interactions in the cervicovaginal environment and their role in spontaneous preterm birth

Differences in the cervicovaginal microbiota are associated with spontaneous preterm birth (sPTB), a significant cause of infant morbidity and mortality. Although establishing a direct causal link between cervicovaginal microbiota and sPTB remains challenging, recent advancements in sequencing technologies have facilitated the identification of microbial markers potentially linked to sPTB. Despite variations in findings, a recurring observation suggests that sPTB is associated with a more diverse and less stable vaginal microbiota across pregnancy trimesters. It is hypothesized that sPTB risk is likely to be modified via an intricate host-microbe interactions rather than due to the presence of a single microbial taxon or broad community state. Nonetheless, lactobacilli dominance is generally associated with term outcomes and contributes to a healthy vaginal environment through the production of lactic acid/maintenance of a low pH that excludes other pathogenic microorganisms. Additionally, the innate immunity of the host and metabolic interactions between cervicovaginal microbiota, such as the production of bacteriocins and the use of proteolytic enzymes, exerts a profound influence on microbial populations, activities, and host immune responses. These interplays collectively impact pregnancy outcomes. This review aims to summarize the complexity of cervicovaginal environment and microbiota dynamics, and associations with bacterial vaginosis and sPTB. There is also consideration on how probiotics may mitigate the risk of sPTB and bacterial vaginosis.

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

IMPORTANCE

Infertility 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.

Predicting preterm birth using machine learning techniques in oral microbiome

Preterm birth prediction is essential for improving neonatal outcomes. While many machine learning techniques have been applied to predict preterm birth using health records, inflammatory markers, and vaginal microbiome data, the role of prenatal oral microbiome remains unclear. This study aimed to compare oral microbiome compositions between a preterm and a full-term birth group, identify oral microbiome associated with preterm birth, and develop a preterm birth prediction model using machine learning of oral microbiome compositions. Participants included singleton pregnant women admitted to Jeonbuk National University Hospital between 2019 and 2021. Subjects were divided into a preterm and a full-term birth group based on pregnancy outcomes. Oral microbiome samples were collected using mouthwash within 24 h before delivery and 16S ribosomal RNA sequencing was performed to analyze taxonomy. Differentially abundant taxa were identified using DESeq2. A random forest classifier was applied to predict preterm birth based on the oral microbiome. A total of 59 women participated in this study, with 30 in the preterm birth group and 29 in the full-term birth group. There was no significant difference in maternal clinical characteristics between the preterm and the full-birth group. Twenty-five differentially abundant taxa were identified, including 22 full-term birth-enriched taxa and 3 preterm birth-enriched taxa. The random forest classifier achieved high balanced accuracies (0.765 ± 0.071) using the 9 most important taxa. Our study identified 25 differentially abundant taxa that could differentiate preterm and full-term birth groups. A preterm birth prediction model was developed using machine learning of oral microbiome compositions in mouthwash samples. Findings of this study suggest the potential of using oral microbiome for predicting preterm birth. Further multi-center and larger studies are required to validate our results before clinical applications.

Comparison of vaginal microbiota between women with inflammatory bowel disease and healthy controls

BACKGROUND

The gut microbiota in patients with inflammatory bowel disease are perturbed in both composition and function. The vaginal microbiome and its role in the reproductive health of women with inflammatory bowel disease is less well described.

OBJECTIVE

We aim to compare the vaginal microbiota of women with inflammatory bowel disease to healthy controls.

METHODS

Women with inflammatory bowel disease enrolled in a longitudinal cohort study provided self-collected vaginal swabs. Healthy controls underwent provider-collected vaginal swabs at routine gynecologic exams. All participants completed surveys on health history, vulvovaginal symptoms and gastrointestinal symptoms, if applicable. Microbiota were characterized by sequencing the V4 region of the 16S rRNA gene. Associations between patient characteristics and microbial community composition were evaluated by PERMANOVA and Principal Components Analysis. Lactobacillus dominance of the microbial community was compared between groups using chi-square and Poisson regression.

RESULTS

The cohort included 54 women with inflammatory bowel disease (25 Ulcerative colitis, 25 Crohn's Disease) and 26 controls. A majority, 72 (90%) were White; 17 (31%) with inflammatory bowel disease and 7 (27%) controls were postmenopausal. The composition of the vaginal microbiota did not vary significantly by diagnosis or severity of inflammatory bowel disease but did vary by menopausal status (p = 0.042). There were no significant differences in Shannon Diversity Index between healthy controls and women with IBD in premenopausal participants. There was no difference in proportion of Lactobacillus dominance according to diagnosis in premenopausal participants. A subgroup of postmenopausal women with Ulcerative colitis showed a significant higher alpha diversity and a lack of Lactobacillus dominance in the vaginal microbiome.

CONCLUSIONS

Menopausal status had a larger impact on vaginal microbial communities than inflammatory bowel disease diagnosis or severity.

A new hypothesis on BV etiology: dichotomous and crisscrossing categorization of complex versus simple on healthy versus BV vaginal microbiomes

IMPORTANCE

BV may influence as many as one-third of women, but its etiology remains unclear. A traditional view is that dominance by Lactobacillus is the hallmark of a healthy vaginal microbiome and lack of dominance may make women BV-prone. Recent studies show that the human VMs can be classified into five major types, four of which possess type-specific dominant species of Lactobacillus. The remaining one (type IV) is not dominated by Lactobacillus and contains a handful of strictly anaerobic bacteria. Nevertheless, exceptions to the first hypothesis have been noticed from the very beginning, and there is not a definite relationship, suggested yet, between the five VM types and BV status. Here, we propose and test a novel hypothesis that assumes the existence of four VM types from dichotomous crisscrossing of "complex versus simple (high diversity or low dominance versus low diversity or high dominance)" on "healthy versus BV." Consequently, there are simple BV versus complex BV.

Longitudinal assessment of bacterial vaginosis prior to and during incident pregnancy: an observational study in Kenyan adolescent girls and young women

OBJECTIVE

To determine bacterial vaginosis (BV) status at multiple time points among adolescent girls and young women (AGYW) and assess the impact of pregnancy on their BV status.

DESIGN

Longitudinal cohort study.

SETTING

Thika, Kenya.

PARTICIPANTS

AGYW aged 16-20 years enrolled prior to first sex or reporting only a single lifetime partner.

MAIN OUTCOME MEASURES

The primary outcome was relative risk (RR) of BV during pregnancy compared with before pregnancy by analysing longitudinal trends in BV over time. BV risk was estimated using Poisson regression models.

RESULTS

A total of 121 AGYW became pregnant in the parent cohort and had BV results before, during or after pregnancy. Point prevalence of BV was 11.0% at visits >12 months pre-pregnancy, 13.0% at 3-12 months pre-pregnancy, 22.1% at <3 months pre-pregnancy and 13.4% during pregnancy. Compared with visits during pregnancy, RR of BV was 1.65 (95% CI: 1.00 to 2.71; p=0.05) at visits <3 months pre-pregnancy, 0.97 (95% CI: 0.62 to 1.52; p=0.90) at visits 3-12 months pre-pregnancy and 0.82 (95% CI: 0.44 to 1.53; p=0.53) at visits 12 months pre-pregnancy. An adjusted analysis including age, income, residence, date of first sex, recent sexual activity and positive sexually transmitted infection test resulted in small changes in risk estimates, with adjusted RR of BV of 1.66 (95% CI: 1.04 to 2.67; p=0.04) at visits <3 months pre-pregnancy compared with visits during pregnancy.

CONCLUSIONS

BV risk during pregnancy was lower than during the immediate pre-pregnancy period. Hormonal changes in pregnancy may reduce BV.

Cervical and Vaginal Microbiomes in Early Miscarriages and Ongoing Pregnancy with and without Dydrogesterone Usage

Emerging evidence suggests that the reproductive tract microbiota is a key modulator of local inflammatory and immune pathways throughout pregnancy and may subsequently impact pregnancy outcomes. In this study, our objective was to analyze the cervical and vaginal microbiomes during early pregnancy among three groups: women with healthy ongoing pregnancies, women undergoing dydrogesterone treatment, and those who experienced miscarriages. The experiment involved 51 women at 8-11 weeks of gestation. The microbiome was examined using 16S rRNA sequencing on the Ion Torrent PGM platform. Across all groups, Lactobacillus iners was predominant, suggesting that the vaginal community type CST III is common among the majority of participants. Notably, our data highlighted the significant roles of Gardnerella vaginalis and Mycoplasma girerdii in the pathogenesis of early miscarriage. Conversely, L. iners and Bifidobacterium longum have a protective effect in early pregnancy. Moreover, dydrogesterone intake appeared to influence notable differences between the cervical and vaginal microbiomes. Overall, our study enhanced our understanding of the cervical and vaginal microbiome composition in the eastern European population during early pregnancy.

New Insights into Photobiomodulation of the Vaginal Microbiome-A Critical Review

The development of new technologies such as sequencing has greatly enhanced our understanding of the human microbiome. The interactions between the human microbiome and the development of several diseases have been the subject of recent research. In-depth knowledge about the vaginal microbiome (VMB) has shown that dysbiosis is closely related to the development of gynecologic and obstetric disorders. To date, the progress in treating or modulating the VMB has lagged far behind research efforts. Photobiomodulation (PBM) uses low levels of light, usually red or near-infrared, to treat a diversity of conditions. Several studies have demonstrated that PBM can control the microbiome and improve the activity of the immune system. In recent years, increasing attention has been paid to the microbiome, mostly to the gut microbiome and its connections with many diseases, such as metabolic disorders, obesity, cardiovascular disorders, autoimmunity, and neurological disorders. The applicability of PBM therapeutics to treat gut dysbiosis has been studied, with promising results. The possible cellular and molecular effects of PBM on the vaginal microbiome constitute a theoretical and promising field that is starting to take its first steps. In this review, we will discuss the potential mechanisms and effects of photobiomodulation in the VMB.

Exploring the genotypic and phenotypic differences distinguishing Lactobacillus jensenii and Lactobacillus mulieris

Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii are dominant species of the urogenital microbiota. Prior studies suggest that these Lactobacillus species play a significant role in the urobiome of healthy females. In our prior genomic analysis of all publicly available L. jensenii and Lactobacillus mulieris genomes at the time (n = 43), we identified genes unique to these two closely related species. This motivated our further exploration here into their genotypic differences as well as into their phenotypic differences. First, we expanded genome sequence representatives of both species to 61 strains, including publicly available strains and nine new strains sequenced here. Genomic analyses conducted include phylogenetics of the core genome as well as biosynthetic gene cluster analysis and metabolic pathway analyses. Urinary strains of both species were assayed for their ability to utilize four simple carbohydrates. We found that L. jensenii strains can efficiently catabolize maltose, trehalose, and glucose, but not ribose, and L. mulieris strains can utilize maltose and glucose, but not trehalose and ribose. Metabolic pathway analysis clearly shows the lack of treB within L. mulieris strains, indicative of its inability to catabolize external sources of trehalose. While genotypic and phenotypic observations provide insight into the differences between these two species, we did not find any association with urinary symptom status. Through this genomic and phenotypic investigation, we identify markers that can be leveraged to clearly distinguish these two species in investigations of the female urogenital microbiota. IMPORTANCE We have expanded upon our prior genomic analysis of L. jensenii and L. mulieris strains, including nine new genome sequences. Our bioinformatic analysis finds that L. jensenii and L. mulieris cannot be distinguished by short-read 16S rRNA gene sequencing alone. Thus, to discriminate between these two species, future studies of the female urogenital microbiome should employ metagenomic sequencing and/or sequence species-specific genes, such as those identified here. Our bioinformatic examination also confirmed our prior observations of differences between the two species related to genes associated with carbohydrate utilization, which we tested here. We found that the transport and utilization of trehalose are key distinguishing traits of L. jensenii, which is further supported by our metabolic pathway analysis. In contrast with other urinary Lactobacillus species, we did not find strong evidence for either species, nor particular genotypes, to be associated with lower urinary tract symptoms (or the lack thereof).

Development of Gut Microbiota in the First 1000 Days after Birth and Potential Interventions

The first 1000 days after birth represent a critical window for gut microbiome development, which is essential for immune system maturation and overall health. The gut microbiome undergoes major changes during this period due to shifts in diet and environment. Disruptions to the microbiota early in life can have lasting health effects, including increased risks of inflammatory disorders, autoimmune diseases, neurological disorders, and obesity. Maternal and environmental factors during pregnancy and infancy shape the infant gut microbiota. In this article, we will review how maintaining a healthy gut microbiome in pregnancy and infancy is important for long-term infant health. Furthermore, we briefly include fungal colonization and its effects on the host immune function, which are discussed as part of gut microbiome ecosystem. Additionally, we will describe how potential approaches such as hydrogels enriched with prebiotics and probiotics, gut microbiota transplantation (GMT) during pregnancy, age-specific microbial ecosystem therapeutics, and CRISPR therapies targeting the gut microbiota hold potential for advancing research and development. Nevertheless, thorough evaluation of their safety, effectiveness, and lasting impacts is crucial prior to their application in clinical approach. The article emphasizes the need for continued research to optimize gut microbiota and immune system development through targeted early-life interventions.

The Vaginal Microbiota of Pregnant Women Varies with Gestational Age, Maternal Age, and Parity

The composition of the vaginal microbiota is heavily influenced by pregnancy and may factor into pregnancy complications, including spontaneous preterm birth. However, results among studies have been inconsistent due, in part, to variation in sample sizes and ethnicity. Thus, an association between the vaginal microbiota and preterm labor continues to be debated. Yet, before assessing associations between the composition of the vaginal microbiota and preterm labor, a robust and in-depth characterization of the vaginal microbiota throughout pregnancy in the specific study population under investigation is required. Here, we report a large longitudinal study (n = 474 women, 1,862 vaginal samples) of a predominantly African-American cohort-a population that experiences a relatively high rate of pregnancy complications-evaluating associations between individual identity, gestational age, and other maternal characteristics with the composition of the vaginal microbiota throughout gestation resulting in term delivery. The principal factors influencing the composition of the vaginal microbiota in pregnancy are individual identity and gestational age at sampling. Other factors are maternal age, parity, obesity, and self-reported Cannabis use. The general pattern across gestation is for the vaginal microbiota to remain or transition to a state of Lactobacillus dominance. This pattern can be modified by maternal parity and obesity. Regardless, network analyses reveal dynamic associations among specific bacterial taxa within the vaginal ecosystem, which shift throughout the course of pregnancy. This study provides a robust foundational understanding of the vaginal microbiota in pregnancy and sets the stage for further investigation of this microbiota in obstetrical disease. IMPORTANCE There is debate regarding links between the vaginal microbiota and pregnancy complications, especially spontaneous preterm birth. Inconsistencies in results among studies are likely due to differences in sample sizes and cohort ethnicity. Ethnicity is a complicating factor because, although all bacterial taxa commonly inhabiting the vagina are present among all ethnicities, the frequencies of these taxa vary among ethnicities. Therefore, an in-depth characterization of the vaginal microbiota throughout pregnancy in the specific study population under investigation is required prior to evaluating associations between the vaginal microbiota and obstetrical disease. This initial investigation is a large longitudinal study of the vaginal microbiota throughout gestation resulting in a term delivery in a predominantly African-American cohort, a population that experiences disproportionally negative maternal-fetal health outcomes. It establishes the magnitude of associations between maternal characteristics, such as age, parity, body mass index, and self-reported Cannabis use, on the vaginal microbiota in pregnancy.

Changes in Vaginal Bacteria and Inflammatory Mediators From Periconception Through the Early Postpartum Period in a Cohort of Kenyan Women Without HIV

BACKGROUND

Women's increased risk of HIV acquisition during pregnancy and postpartum may be mediated by changes in vaginal microbiota and/or cytokines.

METHODS

A cohort of 80 Kenyan women who were HIV-1 seronegative contributed 409 vaginal samples at 6 pregnancy time points: periconception, positive pregnancy test result, first trimester, second trimester, third trimester, and postpartum. Concentrations of vaginal bacteria linked with HIV risk and Lactobacillus spp were measured using quantitative polymerase chain reaction. Cytokines were measured by immunoassay.

RESULTS

Based on Tobit regression, later pregnancy time points were associated with lower concentrations of Sneathia spp (P = .01), Eggerthella sp type 1 (P = .002), and Parvimonas sp type 2 (P = .02) and higher concentrations of Lactobacillus iners (P < .001), Lactobacillus crispatus (P < .001), Lactobacillus vaginalis (P < .001), interleukin 6 (P < .001), TNF (P = .004), C-X-C motif chemokine ligand 10 (CXCL10; P < .001), C-C motif ligand 3 (P = .009), C-C motif ligand 4 (P < .001), C-C motif ligand 5 (P = .002), interleukin 1β (P = .02), and interleukin 8 (P = .002). Most cervicovaginal cytokines and vaginal bacteria clustered separately in principal component analysis, except for CXCL10, which did not group with either cytokines or bacteria. The shift toward a Lactobacillus-dominated microbiota during pregnancy mediated the relationship between pregnancy time point and CXCL10.

CONCLUSIONS

Increases in proinflammatory cytokines, but not vaginal bacterial taxa linked with higher HIV risk, could provide an explanation for increased HIV susceptibility during pregnancy and postpartum.

Association of Pregnancy and HIV Status With Molecular-Bacterial Vaginosis in Indian Women

BACKGROUND

Bacterial vaginosis (BV) is a highly prevalent disorder of the cervicovaginal microbiota. Molecular-BV may put women at increased risk for adverse reproductive and obstetric outcomes. We investigated the association of HIV and pregnancy on the vaginal microbiota and associations with molecular-BV in women of reproductive age from Pune, India.

SETTING

We studied vaginal samples from N = 170 women, including N = 44 nonpregnant HIV seronegative, N = 56 pregnant seronegative, N = 47 nonpregnant women with HIV (WWH), and N = 23 pregnant WWH, and collected data on clinical, behavioral, and demographic factors.

METHODS

We used 16S rRNA gene amplicon sequencing to characterize the composition of the vaginal microbiota. We classified the vaginal microbiota of these women into community state types based on bacterial composition and relative abundance and further categorized them into molecular-BV versus Lactobacillus -dominated states. To determine associations between pregnancy and HIV status with outcome of molecular-BV, logistic regression models were used.

RESULTS

There was a high prevalence of molecular-BV (30%) in this cohort. We found that pregnancy was associated with decreased odds of molecular-BV (adjusted OR = 0.35, 95% CI: 0.14 to 0.87), while HIV was associated with increased odds of molecular-BV (adjusted OR = 2.76, 95% CI: 1.33 to 5.73), even when controlling for multiple relevant factors such as age, number of sexual partners, condom use, and douching.

CONCLUSION

Larger and longitudinal studies are needed to further characterize molecular-BV and the vaginal microbiota in pregnant women and WWH and relate these factors to infectious, reproductive, and obstetric outcomes. In the long term, these studies may lead to novel microbiota-based therapeutics to improve women's reproductive and obstetric health.

Advances in mass spectrometry technologies to characterize cervicovaginal microbiome functions that impact spontaneous preterm birth

Preterm birth (PTB) is a leading cause of morbidity and mortality in young children. Infection is a major cause of this adverse outcome, particularly in PTBs characterised by spontaneous rupture of membranes, referred to as spontaneous (s)PTB. However, the aetiology of sPTB is not well defined and specific bacteria associated with sPTB differ between studies and at the individual level. This may be due to many factors including a lack of understanding of strain-level differences in bacteria that influence how they function and interact with each other and the host. Metaproteomics and metabolomics are mass spectrometry-based methods that enable the collection of detailed microbial and host functional information. Technological advances in this field have dramatically increased the resolution of these approaches, enabling the simultaneous detection of thousands of proteins or metabolites. These data can be used for taxonomic analysis of vaginal bacteria and other microbes, to understand microbiome-host interactions, and identify diagnostic biomarkers or therapeutic targets. Although these methods have been used to assess host proteins and metabolites, few have characterized the microbial compartment in the context of pregnancy. The utilisation of metaproteomic and metabolomic-based approaches has the potential to vastly improve our understanding of the mechanisms leading to sPTB.

Categorical Data Analysis for High-Dimensional Sparse Gene Expression Data

Categorical data analysis becomes challenging when high-dimensional sparse covariates are involved, which is often the case for omics data. We introduce a statistical procedure based on multinomial logistic regression analysis for such scenarios, including variable screening, model selection, order selection for response categories, and variable selection. We perform our procedure on high-dimensional gene expression data with 801 patients, 2426 genes, and five types of cancerous tumors. As a result, we recommend three finalized models: one with 74 genes achieves extremely low cross-entropy loss and zero predictive error rate based on a five-fold cross-validation; and two other models with 31 and 4 genes, respectively, are recommended for prognostic multi-gene signatures.

Association between vaginal microbiomes and neonatal septicemia in pregnant women with preterm premature rupture of membranes based on metagenome sequencing

BACKGROUND

Preterm premature rupture of membranes (PPROM) is closely associated with pathogenic microbiomes in the female reproductive tract, and can lead to neonatal septicemia. The current study aimed to investigate potential pathogenic microbiomes associated with neonatal septicemia based on DNA metagenome sequencing.

METHODS

In this study, a total of 7 pregnant women with PPROM presenting neonatal septicemia (experimental group) and 3 pregnant women with normal newborns (control group) were enrolled. Vaginal secretions at admission and before parturition as well as placental tissues after parturition were collected for DNA metagenome sequencing using whole genome shotgun method on the Illumina NovaSeq/HiSeq platform. Raw data were processed by BioBakery workflow, and MetaPhlAn4 was implemented for qualitative and quantitative analyses of microbiome. Lactobacillus crispatus, Gardneralla vaginalis, Fannyhessea vaginae and Streptococcus suis were specifically detected from the experimental group. The two groups were compared using Student's t-tests.

RESULTS

The indexes of Chao1 (P=0.00028/P=0.00072), abundance-based coverage estimator (ACE, P=0.00059/P=0.00026), Shannon (P=0.036/P=0.0065) and Simpson (P=0.007/P=0.041) in the experimental group were increased at admission and before parturition as compared with the control group. Several microbiomes, such as Lactobacillus crispatus, Gardneralla vaginalis, Fannyhessea vaginae and Streptococcus suis, were specifically detected in the experimental group. Notably, Gardnerella vaginalis and Streptococcus gallolyticus were identified from the vaginal secretions and placenta tissues of women with neonatal septicemia. Moreover, nucleic acid synthesis and carbohydrate metabolism-related pathways were enriched in the experimental group.

CONCLUSION

This study enhanced the current understanding of the mechanisms underlying pathogenic microbiomes in PPROM-induced neonatal septicemia. The trial registry number is ChiCTR2300070666 (URL: https://www.chictr.org.cn/showproj.html?proj=195648).

Glycogen availability and pH variation in a medium simulating vaginal fluid influence the growth of vaginal Lactobacillus species and Gardnerella vaginalis

BACKGROUND

Glycogen metabolism by Lactobacillus spp. that dominate the healthy vaginal microbiome contributes to a low vaginal pH (3.5-4.5). During bacterial vaginosis (BV), strict and facultative anaerobes including Gardnerella vaginalis become predominant, leading to an increase in the vaginal pH (> 4.5). BV enhances the risk of obstetrical complications, acquisition of sexually transmitted infections, and cervical cancer. Factors critical for the maintenance of the healthy vaginal microbiome or the transition to the BV microbiome are not well defined. Vaginal pH may affect glycogen metabolism by the vaginal microflora, thus influencing the shift in the vaginal microbiome.

RESULTS

The medium simulating vaginal fluid (MSVF) supported growth of L. jensenii 62G, L. gasseri 63 AM, and L. crispatus JV-V01, and G. vaginalis JCP8151A at specific initial pH conditions for 30 d. L. jensenii at all three starting pH levels (pH 4.0, 4.5, and 5.0), G. vaginalis at pH 4.5 and 5.0, and L. gasseri at pH 5.0 exhibited the long-term stationary phase when grown in MSVF. L. gasseri at pH 4.5 and L. crispatus at pH 5.0 displayed an extended lag phase over 30 d suggesting inefficient glycogen metabolism. Glycogen was essential for the growth of L. jensenii, L. crispatus, and G. vaginalis; only L. gasseri was able to survive in MSVF without glycogen, and only at pH 5.0, where it used glucose. All four species were able to survive for 15 d in MSVF with half the glycogen content but only at specific starting pH levels - pH 4.5 and 5.0 for L. jensenii, L. gasseri, and G. vaginalis and pH 5.0 for L. crispatus.

CONCLUSIONS

These results suggest that variations in the vaginal pH critically influence the colonization of the vaginal tract by lactobacilli and G. vaginalis JCP8151A by affecting their ability to metabolize glycogen. Further, we found that L. jensenii 62G is capable of glycogen metabolism over a broader pH range (4.0-5.0) while L. crispatus JV-V01 glycogen utilization is pH sensitive (only functional at pH 5.0). Finally, our results showed that G. vaginalis JCP8151A can colonize the vaginal tract for an extended period as long as the pH remains at 4.5 or above.

Abrupt perturbation and delayed recovery of the vaginal ecosystem following childbirth

The vaginal ecosystem is closely tied to human health and reproductive outcomes, yet its dynamics in the wake of childbirth remain poorly characterized. Here, we profile the vaginal microbiota and cytokine milieu of participants sampled longitudinally throughout pregnancy and for at least one year postpartum. We show that delivery, regardless of mode, is associated with a vaginal pro-inflammatory cytokine response and the loss of Lactobacillus dominance. By contrast, neither the progression of gestation nor the approach of labor strongly altered the vaginal ecosystem. At 9.5-months postpartum-the latest timepoint at which cytokines were assessed-elevated inflammation coincided with vaginal bacterial communities that had remained perturbed (highly diverse) from the time of delivery. Time-to-event analysis indicated a one-year postpartum probability of transitioning to Lactobacillus dominance of 49.4%. As diversity and inflammation declined during the postpartum period, dominance by L. crispatus, the quintessential health-associated commensal, failed to return: its prevalence before, immediately after, and one year after delivery was 41%, 4%, and 9%, respectively. Revisiting our pre-delivery data, we found that a prior live birth was associated with a lower odds of L. crispatus dominance in pregnant participants-an outcome modestly tempered by a longer ( > 18-month) interpregnancy interval. Our results suggest that reproductive history and childbirth in particular remodel the vaginal ecosystem and that the timing and degree of recovery from delivery may help determine the subsequent health of the woman and of future pregnancies.

An Overview of the Microbiota of the Human Urinary Tract in Health and Disease: Current Issues and Perspectives

This article is intended to deepen our knowledge to date regarding the functions of the resident microbiota/microbiome in the urinary system for human health and disease. First, we sought to report the general characteristics (composition and stability) of the normal urinary system microbiota in the different anatomical sites in relation to some factors such as the effect of age, gender and diet, analyzing in detail the functions and the composition of the microbiota in the light of current knowledge. Several pieces of evidence suggest the importance of preserving the micro-ecosystem of the urinary system, and in some cases their relationship with diseases is important for maintaining human health is well understood. The female and male reproductive microbiota have mainly been studied over the past decade. In the past, the arrest was thought to have taken place in a sterile environment. Microorganisms of the microbiota form biofilms, three-dimensional structures, that differ in the reproductive organs and interact with both gametes and the embryo as well as with maternal tissues. These biofilms from the reproductive system also interact with others, such as that of the gastrointestinal tract. Reduction in its diversity intestinal microbiota can disrupt estrogen metabolism and affect the reproductive microbiota. It is therefore understood that its quantitative and qualitative identification is important for microbiota, but also the study of the structures formed by the microorganisms. A dysbiosis with local or systemic causes can lead to serious diseases. The role of probiotics in maintaining microbial population harmony (eubiosis) and preventing certain pathologies of the urinary and reproductive system was also investigated. A negative variation in the qualitative and quantitative composition of certain strains of microorganisms (dysbiosis) due to local or systemic causes can even lead to serious diseases. The role of probiotics in maintaining the healthy balance of microorganism populations (eubiosis), and thus in the prevention of certain pathologies of the urinary and reproductive system, has also been studied.

Partial convergence of the human vaginal and rectal maternal microbiota in late gestation and early post-partum

The human vaginal and fecal microbiota change during pregnancy. Because of the proximity of these perineal sites and the evolutionarily conserved maternal-to-neonatal transmission of the microbiota, we hypothesized that the microbiota of these two sites (rectal and vaginal) converge during the last gestational trimester as part of the preparation for parturition. To test this hypothesis, we analyzed 16S rRNA sequences from vaginal introitus and rectal samples in 41 women at gestational ages 6 and 8 months, and at 2 months post-partum. The results show that the human vaginal and rectal bacterial microbiota converged during the last gestational trimester and into the 2nd month after birth, with a significant decrease in Lactobacillus species in both sites, as alpha diversity progressively increased in the vagina and decreased in the rectum. The microbiota convergence of the maternal vaginal-anal sites perinatally might hold significance for the inter-generational transmission of the maternal microbiota.

The Role of Hydrogen-Peroxide (H2O2) Produced by Vaginal Microbiota in Female Reproductive Health

Female reproductive health is strongly associated with healthy vaginal microbiota, which is thought to be ensured by the dominance of certain Lactobacillus species. Lactobacilli control the vaginal microenvironment through several factors and mechanisms. One of them is their ability to produce hydrogen peroxide (H₂O₂). The role of Lactobacillus-derived H₂O₂ in the vaginal microbial community has been intensively investigated in several studies with many designs. However, results and data are controversial and challenging to interpret in vivo. Defining the underlying mechanisms responsible for a physiological vaginal ecosystem is crucial since it could directly affect probiotic treatment attempts. This review aims to summarize current knowledge on the topic, focusing on probiotic treatment possibilities.

Translational informatics for human microbiota: data resources, models and applications

With the rapid development of human intestinal microbiology and diverse microbiome-related studies and investigations, a large amount of data have been generated and accumulated. Meanwhile, different computational and bioinformatics models have been developed for pattern recognition and knowledge discovery using these data. Given the heterogeneity of these resources and models, we aimed to provide a landscape of the data resources, a comparison of the computational models and a summary of the translational informatics applied to microbiota data. We first review the existing databases, knowledge bases, knowledge graphs and standardizations of microbiome data. Then, the high-throughput sequencing techniques for the microbiome and the informatics tools for their analyses are compared. Finally, translational informatics for the microbiome, including biomarker discovery, personalized treatment and smart healthcare for complex diseases, are discussed.

Vaginal flora during pregnancy and subsequent risk of preterm birth or prelabor rupture of membranes: a nested case-control study from China

BACKGROUND

The findings of the association of vaginal flora with preterm birth (PTB) or prelabor rupture of membranes (PROM) were conflicts. Moreover, vaginal flora was different by ethnicity and the evidence from China was limited.

METHODS

This study was a nested case control study, based on Yiwu birth cohort. We assessed vaginal microbiota in the second or third trimester, using 16S rDNA Amplicon Sequencing and explored the association between the diversity and composition of vaginal flora and PTB or PROM.

RESULTS

We finally included 144 pregnant women. In present study, the alpha diversity of TPROM (Term prelabor rupture of membranes) samples was lower than that of full term samples (Chao1 index: P < 0.05). When we further categorized PTB (Preterm birth) into SPB (PTB without PROM) and PPROM (Preterm prelabor rupture of membranes), there was no difference between SPB and full term. In addition, we found that the proportion of PCoA2 in TPROM group was different from that in full term group and preterm group. The difference between groups was significant according to anosim analysis (R = 0.059, P < 0.001). With LEfSe (Linear discriminant analysis Effect Size) analysis, we found that the abundance of Lactobacillus in the vaginal flora of pregnant women with preterm birth was the highest (P = 0.003).

CONCLUSION

In Chinese pregnant women, the alpha diversity in TPROM group was significantly lower than that in both PTB and full term group. However, there was no difference between PTB and full term. Lactobacillus was the most abundant in preterm birth group. More studies should be conducted to confirm our findings.

Advances in Research on the Relationship between Vaginal Microbiota and Adverse Pregnancy Outcomes and Gynecological Diseases

The human microbiota inhabiting different parts of the body has been shown to have a significant impact on human health, with the gut microbiota being the most extensively studied in relation to disease. However, the vaginal microbiota is also an essential commensal microbiota in the female body that plays a crucial role in female health. Despite receiving less attention than gut microbiota, its importance in regulating reproductive immunity and its complex dynamic properties have been increasingly recognized in recent years. Advances in research on the relationship between vaginal microbiota and pregnancy outcomes & gynecological diseases in women have shed light on the importance of maintaining a healthy vaginal microbiota. In this review, we aim to compile recent developments in the study of the vaginal microbial ecosystem and its role in female health and reproductive outcomes. We provide a comprehensive account of the normal vaginal microbiota, the association between the vaginal microbiota and pregnancy outcomes, and the impact of the vaginal microbiota on gynecological diseases in women. By reviewing recent research, we hope to contribute to the advancement of academic medicine's understanding of the vaginal microbiota's importance in female health. We also aim to raise awareness among healthcare professionals and the general public of the significance of maintaining a healthy vaginal microbiota for better reproductive health and the prevention of gynecological diseases.

Microbial transmission, colonisation and succession: from pregnancy to infancy

The microbiome has been proven to be associated with many diseases and has been used as a biomarker and target in disease prevention and intervention. Currently, the vital role of the microbiome in pregnant women and newborns is increasingly emphasised. In this review, we discuss the interplay of the microbiome and the corresponding immune mechanism between mothers and their offspring during the perinatal period. We aim to present a comprehensive picture of microbial transmission and potential immune imprinting before and after delivery. In addition, we discuss the possibility of in utero microbial colonisation during pregnancy, which has been highly debated in recent studies, and highlight the importance of the microbiome in infant development during the first 3 years of life. This holistic view of the role of the microbial interplay between mothers and infants will refine our current understanding of pregnancy complications as well as diseases in early life and will greatly facilitate the microbiome-based prenatal diagnosis and treatment of mother-infant-related diseases.

Univariate and Multivariate Statistical Analysis of Microbiome Data: An Overview

Microbiome data is high dimensional, sparse, compositional, and over-dispersed. Therefore, modeling microbiome data is very challenging and it is an active research area. Microbiome analysis has become a progressing area of research as microorganisms constitute a large part of life. Since many methods of microbiome data analysis have been presented, this review summarizes the challenges, methods used, and the advantages and disadvantages of those methods, to serve as an updated guide for those in the field. This review also compared different methods of analysis to progress the development of newer methods.

Vulvovaginal yeast infections during pregnancy and perinatal outcomes: systematic review and meta-analysis

BACKGROUND

Vulvovaginal yeast infections in pregnancy are common and can cause extensive inflammation, which could contribute to adverse pregnancy outcomes. Symptomatic yeast infections are likely to cause more inflammation than asymptomatic. The objective of this study was to investigate associations between symptomatic and asymptomatic vulvovaginal yeast infections in pregnancy and perinatal outcomes.

METHODS

We did a systematic review and searched eight databases until 01 July 2022. We included studies reporting on pregnant women with and without laboratory confirmed vulvovaginal yeast infection and preterm birth or eight other perinatal outcomes. We used random effects meta-analysis to calculate summary odds ratios (OR), 95% confidence intervals (CI) and prediction intervals for the association between yeast infection and outcomes. We described findings from studies with multivariable analyses. We assessed the risk of bias using published tools.

RESULTS

We screened 3909 references and included 57 studies. Only 22/57 studies reported information about participant vulvovaginal symptoms. Preterm birth was an outcome in 35/57 studies (49,161 women). In 32/35 studies with available data, the summary OR from univariable analyses was 1.01 (95% CI 0.84-1.21, I2 60%, prediction interval 0.45-2.23). In analyses stratified by symptom status, we found ORs of 1.44 (95% CI 0.92-2.26) in two studies with ≥ 50% symptomatic participants, 0.84 (95% CI 0.45-1.58) in seven studies with < 50% symptomatic participants, and 1.12 (95% CI 0.94-1.35) in four studies with asymptomatic participants. In three studies with multivariable analysis, adjusted ORs were greater than one but CIs were compatible with there being no association. We did not find associations between vulvovaginal yeast infection and any secondary outcome. Most studies were at high risk of bias in at least one domain and only three studies controlled for confounding.

CONCLUSIONS

We did not find strong statistical evidence of an increased risk for preterm birth or eight other adverse perinatal outcomes, in pregnant women with either symptomatic or asymptomatic vulvovaginal yeast infection. The available evidence is insufficient to make recommendations about testing and treatment of vulvovaginal yeast infection in pregnancy. Future studies should assess vulvovaginal symptoms, yeast organism loads, concomitant vaginal or cervical infections, and microbiota using state-of-the-art diagnostics.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020197564.

Maternal vaginal fluids play a major role in the colonization of the neonatal intestinal microbiota

Background

Caesarean section (CS) is associated with newborns’ health risks due to the blocking of microbiome transfer. The gut microbiota of CS-born babies was different from those born vaginally, which may be attributed to reduced exposure to maternal vaginal microbes during labour. To understand the microbial transfer and reduce CS disadvantages, the effect of vaginal microbiota exposure on infant gut microbiota composition was evaluated using 16s rDNA sequencing-based techniques.

Results

Pregnant women were recruited in the Women and Children’s Hospital, School of Medicine, Xiamen University from June 1st to August 15th, 2017. Maternal faeces (n = 26), maternal vaginal fluids (n = 26), and neonatal transitional stools (n = 26) were collected, while the participants underwent natural delivery (ND) (n = 6), CS (n = 4) and CS with the intervention of vaginal seedings (I) (n = 16). 26 mothers with the median age 26.50 (25.00-27.25) years showed no substantial clinical differences. The newborns’ gut microbiota altered among ND, CS and I, and clustered into two groups (PERMANOVA P = 0.001). Microbial composition of ND babies shared more features with maternal vaginal samples (PERMANOVA P = 0.065), while the microbiota structure of ND babies was obviously different from that of sample of maternal faeces. The genus Bacteroides in CS-born babies with intervention approached to vaginal-born neonates, compared with CS-born neonates without intervention.

Conclusions

Neonatal gut microbiota was dependent on the delivery mode. And the gut microbiota CS newborns with vaginal seeding shared more features with those of ND babies, which hinted the aberrant gut microbiota composition initiated by CS might be partly mitigated by maternal vaginal microbiota exposure.

Microbiota dysbiosis and myasthenia gravis: Do all roads lead to Rome?

Dysregulated immune system with a failure to recognize self from non-self-antigens is one of the common pathogeneses seen in autoimmune diseases. The complex interplay of genetic and environmental factors is important for the occurrence and development of the disease. Among the environmental factors, disturbed gut microbiota (gut dysbiosis) has recently attracted particular attention, especially with advancement in human microbiome research. Although the alterations in microbiota have been seen in various autoimmune diseases, including those of nervous system, there is paucity of information on neuromuscular system diseases. Myasthenia gravis (MG) is one such rare autoimmune disease of neuromuscular junction, and is caused by generation of pathogenic autoantibodies to components of the postsynaptic muscle endplate. In the recent years, accumulating evidences have endorsed the key role of host microbiota, particularly those of gut, in the pathogenesis of MG. Differential microbiota composition, characterized by increased abundance of Fusobacteria, Bacteroidetes, and Proteobacteria, and decreased abundance of Actinobacteria and Firmicutes, has been seen in MG patients in comparison to healthy subjects. Disturbance of microbiota composition, particularly reduced ratio of Firmicutes/Bacteroidetes, alter the gut permeability, subsequently triggering the immunological response. Resultant reduction in levels of short chain fatty acids (SCFAs) is another factor contributing to the immunological response in MG patients. Modulation of gut microbiota via intervention of probiotics, prebiotics, synbiotics, postbiotics (metabiotics), and fecal microbiota transplantation (FMT) is considered to be the futuristic approach for the management of MG. This review summarizes the role of gut microbiota and their metabolites (postbiotics) in the progression of MG. Also, various bacteriotherapeutic approaches involving gut microbiota are discussed for the prevention of MG progression.

A pilot study using unique targeted testing of the urogenital microbiome has potential as a predictive test during IVF for implantation outcome

PURPOSE

This pilot study aimed to develop a methodology characterising the urogenital microbiome as a predictive test in the IVF workup.

METHODS

Using unique custom qPCRs, we tested for the presence of specific microbial species from vaginal samples and First Catch Urines from the male. The test panel included a range of potential urogenital pathogens, STIs, 'favourable bacteria' (Lactobacillus spp.) and 'unfavourable bacteria' (anaerobes) reported to influence implantation rates. We tested couples attending Fertility Associates, Christchurch, New Zealand for their first round of IVF.

RESULTS

We found that some microbial species affected implantation. The qPCR result was interpreted qualitatively using the Z proportionality test. Samples from women at the time of Embryo Transfer who did not achieve implantation had significantly higher percent of samples that were positive for Prevotella bivia and Staphylococcus aureus compared to women who did achieve implantation.

DISCUSSION

The results provide evidence that most other microbial species chosen for testing had little functional effect on implantation rates. The addition of further microbial targets (yet to be determined) could be combined in this predictive test for vaginal preparedness on the day of embryo transfer. This methodology has a substantial advantage of being affordable and easily performed in any routine molecular laboratory. This methodology is most suitable as a foundation on which to develop a timely test of microbiome profiling. Using the indicators detected to have a significant influence, these results can be extrapolated.

CONCLUSION

Using a rapid antigen test, a woman can self-sample prior to embryo transfer and obtain an indication of microbial species present which could influence implantation outcome.

The Skin Microbiome: Current Landscape and Future Opportunities

Our skin is the largest organ of the body, serving as an important barrier against the harsh extrinsic environment. Alongside preventing desiccation, chemical damage and hypothermia, this barrier protects the body from invading pathogens through a sophisticated innate immune response and co-adapted consortium of commensal microorganisms, collectively termed the microbiota. These microorganisms inhabit distinct biogeographical regions dictated by skin physiology. Thus, it follows that perturbations to normal skin homeostasis, as occurs with ageing, diabetes and skin disease, can cause microbial dysbiosis and increase infection risk. In this review, we discuss emerging concepts in skin microbiome research, highlighting pertinent links between skin ageing, the microbiome and cutaneous repair. Moreover, we address gaps in current knowledge and highlight key areas requiring further exploration. Future advances in this field could revolutionise the way we treat microbial dysbiosis associated with skin ageing and other pathologies.

Prebiotic Activity of Vaginal Lactobacilli on Bifidobacteria: from Concept to Formulation

The gut of babies born vaginally is rapidly colonized by Bifidobacterium spp. after birth, while in infants born by cesarean section (C-section), the presence of bifidobacteria drops dramatically, increasing the risk of developing gastrointestinal disorders. Considering that newborns naturally come into contact with maternal lactobacilli as they pass through the birth canal, the aim of this work is to exploit for the first time the bifidogenic activity exerted by the cell-free supernatants (CFSs) from lactobacilli of vaginal origin, belonging to the species Lactobacillus crispatus, Lactobacillus gasseri, Limosilactobacillus vaginalis, and Lactiplantibacillus plantarum. CFSs were recovered after 7 h, 13 h, and 24 h of fermentation and assessed for the ability to stimulate the planktonic growth and biofilms of Bifidobacterium strains belonging to species widely represented in the gut tract. A bifidogenic effect was observed for all CFSs; such activity was maximal for CFSs recovered in exponential phase and was strongly dependent on the species of lactobacilli. Importantly, no stimulating effects on an intestinal Escherichia coli strain were observed. CFSs from L. vaginalis BC17 showed the best bifidogenic profile since they increased bifidobacterial planktonic growth by up to 432% and biofilm formation by up to 289%. The CFS at 7 h from BC17 was successfully formulated with a hyaluronic acid-based hydrogel aimed at preventing and treating breast sores in lactating women and exerting bifidogenic activity in infants born mainly by C-section. IMPORTANCE Bifidobacteria in the gut tract of infants play crucial roles in the prevention of gastrointestinal diseases and the maturation of the immune system. Consequently, strategies to trigger a bifidogenic shift in the infant gut are highly desirable. Evidences suggest that the presence of a maternal vaginal microbiota dominated by health-promoting lactobacilli and the development of a bifidobacterium-enriched gut microbiota in newborns are interconnected. In this context, we found out that the cell-free supernatants from lactobacilli of vaginal origin were able to effectively stimulate the proliferation of Bifidobacterium spp. grown in free-floating and biofilm forms. The cell-free supernatant from Limosilactobacillus vaginalis BC17 showed excellent bifidogenic behavior, which was preserved even after its incorporation into a nipple formulation for lactating women. Lactobacilli derivatives, such as cell-free supernatants, have gained increasing interest by virtue of their safer profile than that of living cells and can be proposed as an ecosustainable approach to favor gut colonization of infants by bifidobacteria.