Translating the vaginal microbiome: gaps and challenges

Comparison of the urinary microbiome in men who have sex with men with and without Chlamydia trachomatis infection

PURPOSE

The urinary tract is colonized by microbial communities that impact urinary health. Previous studies have suggested that the bacterial composition of the male urinary microbiota is related to STIs. This study assessed the bacterial composition of the urinary microbiome in South African MSM with and without C. trachomatis.

METHODS

This study used urine samples from MSM attending care at the King Edward VIII hospital and the Aurum Institute in Durban, South Africa. A total of 200 samples were tested for C. trachomatis infection using the Applied Biosystems™ TaqMan® Assays. Urinary microbiomes of 23 samples were characterized using 16 S rRNA (V3 and V4) gene sequencing on the Illumina MiSeq platform.

RESULTS

Bacterial taxonomic analysis showed a high abundance of Streptococcus, Corynebacterium, and Staphylococcus in all the sequenced samples. Moreover, Prevotella and Lactobacillus were detected in urine samples of MSM. Alpha diversity metrics showed a slight increase in microbial diversity in C. trachomatis positive samples; however, this was not significant (ANOVA, P > 0.05). Principal coordinates analysis (PCoA) showed that the microbiome of C. trachomatis infected MSM was not clearly different from those uninfected. Distinct bacterial communities were not detected between positive and negative samples (PERMANOVA F1,22= 1.0284, R2 = 0.047%, P = 0.385).

CONCLUSION

Most microbiome studies on MSM to date have focused on the gut microenvironment. Few studies, however, have provided data regarding the normal composition of the male urethral microbiomes or if these microbiomes are associated with male STIs. This study adds to the growing body of knowledge highlighting the urinary microbiome in MSM.

The microbial revolution: Unveiling the benefits of vaginal probiotics and prebiotics

Vaginal health is essential to a woman's overall well-being, as abnormalities in vaginal health can lead to a variety of gynaecological disorders, such as urinary tract infections, yeast infections, and bacterial vaginosis. The vaginal microbiome is essential for the prevention of these infections. Disruptions in this microbial ecosystem can significantly impact vaginal health. The concept of utilizing probiotics and prebiotics to stimulate the growth of protective vaginal microbiota has gathered substantial interest in recent years. Probiotics are live micro-organisms that strengthen and restore vaginal microbial balance by lowering pH levels, production of bacteriocins, biofilm disruption, modulation of immune response, and production of hydrogen peroxide (H2O2), consequently combating the development of pathogens. Prebiotics are oligosaccharides that encourage the development of probiotics such as lactobacilli species. Probiotics and prebiotics also have some broader implications for vaginal health, including their role in minimizing the incidence of premature birth, optimizing fertility, managing menopausal symptoms, and preventing vaginal infections. Synbiotics are a combination of probiotics and prebiotics that deliver additional benefits by encouraging the development and activity of beneficial microbes. Furthermore, postbiotics are bioactive compounds derived from probiotic bacteria during fermentation that have immunomodulatory actions and provide an additional layer of protection against vaginal infections. The present study highlights the most prevalent vaginal infections and limitations of existing therapies that influence the vaginal microbiota. The profound consequences of probiotics and prebiotics in women's health, including their role in minimizing the prevalence of vaginal infections and promoting overall vaginal health, as well as advanced therapeutic strategies such as synbiotics and postbiotics, are also discussed. The literature offers significant insights into the mechanism, efficacy, and safety of probiotics and prebiotics to healthcare providers and researchers.

Characterization of a Lactobacillus gasseri strain as a probiotic for female vaginitis

Vaginitis, a prevalent gynecological condition in women, is mainly caused by an imbalance in the vaginal micro-ecology. The two most common types of vaginitis are vaginal bacteriosis and vulvovaginal candidiasis, triggered by the virulent Gardnerella vaginalis and Candida albicans, respectively. In this study, a strain capable of inhibiting G. vaginalis and C. albicans was screened from vaginal secretions and identified as Lactobacillus gasseri based on 16S rRNA sequences. The strain, named L. gasseri VHProbi E09, could inhibit the growth of G. vaginalis and C. albicans under co-culture conditions by 99.07% ± 0.26% and 99.95% ± 0.01%, respectively. In addition, it could significantly inhibit the adhesion of these pathogens to vaginal epithelial cells. The strain further showed the ability to inhibit the enteropathogenic bacteria Escherichia coli and Salmonella enteritidis, to tolerate artificial gastric and intestinal fluids and to adhere to intestinal Caco-2 cells. These results suggest that L. gasseri VHProbi E09 holds promise for clinical trials and animal studies whether administered orally or directly into the vagina. Whole-genome analysis also revealed a genome consisting of 1752 genes for L. gasseri VHProbi E09, with subsequent analyses identifying seven genes related to adhesion and three genes related to bacteriocins. These adhesion- and bacteriocin-related genes provide a theoretical basis for understanding the mechanism of bacterial inhibition of the strain. The research conducted in this study suggests that L. gasseri VHProbi E09 may be considered as a potential probiotic, and further research can delve deeper into its efficacy as an agent which can restore a healthy vaginal ecosystem.

Simultaneous application of oral and intravaginal probiotics for Helicobacter pylori and its antibiotic-therapy-induced vaginal dysbacteriosis

Helicobacter pylori is a prevalent bacterial pathogen globally, implicated in various gastrointestinal disorders. Current recommended antibiotic therapies for H. pylori infection have been proven to be therapeutically insufficient, with low eradication rates and high recurrence rates. Emerging evidence suggests that antibiotic therapy for H. pylori can lead to gastrointestinal and subsequent vaginal dysbiosis, posing challenges for conventional antibiotic approaches. Thus, this article proposes a novel probiotic therapy involving simultaneous oral and intra-vaginal probiotic administration alongside antibiotics for H. pylori treatment, aiming to enhance eradication rates and mitigate dysbiosis. We begin by providing an overview of gastrointestinal and vaginal microbiota and their interconnectedness through the vagina-gut axis. We then review the efficacy of current antibiotic regimens for H. pylori and discuss how antibiotic treatment impacts the vaginal microenvironment. To explore the feasibility of this approach, we evaluate the effectiveness of oral and intra-vaginal probiotics in restoring normal microbiota in the gastrointestinal and vaginal tracts, respectively. Additionally, we analyze the direct mechanisms by which oral and intra-vaginal probiotics act on their respective tracts and discuss potential cross-tract mechanisms. Considering the potential synergistic therapeutic effects of probiotics in both the gastrointestinal and vaginal tracts, dual-channel probiotic therapy holds promise as a more effective approach for H. pylori eradication and dysbiosis mitigation, presenting a novel concept in the collaborative treatment of gastrointestinal and genital disorders.

Role of vaginal microbiota in idiopathic infertility: a prospective study

OBJECTIVE

The causes of idiopathic infertility are still not known; however, it may be associated with microbial etiologies. The present study examines the vaginal microbiota of infertile as well as fertile women longitudinally.

METHODOLOGY

The study was presented and accepted by the Institutional Ethical Committee of Shri Mata Vaishno Devi University, Katra, Jammu and Kashmir (India). An observational, prospective, multicenteric investigation was conducted at the Department of Obstetrics and Gynecology, Government Medical College Jammu, and its affiliated hospitals in Jammu and Kashmir (India). In order to examine the microbial composition, a cohort of 80 female individuals were involved in the screening process. The investigation involved sequencing of the V3-V4 region of 16S rRNA gene, which was subsequently analyzed using the Mothur pipeline.

RESULTS

The study revealed that the vaginal microbiota of infertile women differed from that of healthy women who had previously given birth without any complications. Both populations have variations in their alpha as well as beta diversity and taxonomical composition. The microbial profiles in the cases of infertility are characterized by elevated levels of Gardnerella, Prevotella, Atopobium, and Enterococcus whereas a higher level of Lactobacillus iners was observed in case of fertile women.

CONCLUSION

In conclusion, it can be inferred that the composition of the vaginal microbiome potentially exerts a significant influence on females afflicted with idiopathic infertility.

The reproductive microbiome in dogs: Friend or foe?

The microbiome of the reproductive tract is an area of research in full development. Specifically, the microbiome may be involved in reproductive health, disease, and pregnancy outcomes, as has been shown in humans and animals, including dogs. The aim of the present review was to summarize current knowledge on the microbiome of the canine reproductive tract, to expose the controversial role that some bacterial agents may play in canine subfertility, and to highlight future research perspectives. This review discussed whether the use of antimicrobials in dogs is appropriate to increase reproductive performance and to treat subfertility without proper diagnosis, and the possible use of probiotics to modulate the reproductive canine microbiome. Finally, we indicate areas in which scientific knowledge is currently lacking, and could be promising directions for future research.

Association between gut microbiota and menstrual disorders: a two-sample Mendelian randomization study

Background

Evidence from observational studies and clinical trials suggests that the gut microbiota is associated with gynecological diseases. However, the causal relationship between gut microbiota and menstrual disorders remains to be determined.

Methods

We obtained summary data of gut microbiota from the global consortium MiBio-Gen's genome-wide association study (GWAS) dataset and data on menstrual disorders from the IEU Open GWAS project. MR-Egger, weighted median, inverse variance weighted, simple mode, and weighted mode were used to examine the causal association between gut microbiota and menstrual disorders. Thorough sensitivity studies were performed to confirm the data's horizontal pleiotropy, heterogeneity, and robustness.

Results

Through MR analysis of 119 kinds of gut microbiota and 4 kinds of clinical phenotypes, it was discovered that 23 different kinds of gut microbiota were loosely connected to menstrual disorders. After FDR correction, the results showed that only Escherichia/Shigella (p = 0.00032, PFDR = 0.0382, OR = 1.004, 95%CI = 1.002-1.006) is related to menstrual disorders.

Conclusion

According to our MR Analysis, there are indications of a causal relationship between menstrual disorders and gut microbiota. This finding could lead to new discoveries into the mechanisms behind menstrual disorders and clinical research involving the microbiota.

Temporal dynamics of the fecal microbiome in female pigs from early life through estrus, parturition, and weaning of the first litter of piglets

BACKGROUND

Age-associated changes in the gastrointestinal microbiome of young pigs have been robustly described; however, the temporal dynamics of the fecal microbiome of the female pig from early life to first parity are not well understood. Our objective was to describe microbiome and antimicrobial resistance dynamics of the fecal microbiome of breeding sows from early life through estrus, parturition and weaning of the first litter of piglets (i.e., from 3 to 53 weeks of age).

RESULTS

Our analysis revealed that fecal bacterial populations in developing gilts undergo changes consistent with major maturation milestones. As the pigs progressed towards first estrus, the fecal bacteriome shifted from Rikenellaceae RC9 gut group- and UCG-002-dominated enterotypes to Treponema- and Clostridium sensu stricto 1-dominated enterotypes. After first estrus, the fecal bacteriome stabilized, with minimal changes in enterotype transition and associated microbial diversity from estrus to parturition and subsequent weaning of first litter piglets. Unlike bacterial communities, fecal fungal communities exhibited low diversity with high inter- and intra-pig variability and an increased relative abundance of certain taxa at parturition, including Candida spp. Counts of resistant fecal bacteria also fluctuated over time, and were highest in early life and subsequently abated as the pigs progressed to adulthood.

CONCLUSIONS

This study provides insights into how the fecal microbial community and antimicrobial resistance in female pigs change from three weeks of age throughout their first breeding lifetime. The fecal bacteriome enterotypes and diversity are found to be age-driven and established by the time of first estrus, with minimal changes observed during subsequent physiological stages, such as parturition and lactation, when compared to the earlier age-related shifts. The use of pigs as a model for humans is well-established, however, further studies are needed to understand how our results compare to the human microbiome dynamics. Our findings suggest that the fecal microbiome exhibited consistent changes across individual pigs and became more diverse with age, which is a beneficial characteristic for an animal model system.

Integrating compositional and functional content to describe vaginal microbiomes in health and disease

BACKGROUND

A Lactobacillus-dominated vaginal microbiome provides the first line of defense against adverse genital tract health outcomes. However, there is limited understanding of the mechanisms by which the vaginal microbiome modulates protection, as prior work mostly described its composition through morphologic assessment and marker gene sequencing methods that do not capture functional information. To address this gap, we developed metagenomic community state types (mgCSTs) which use metagenomic sequences to describe and define vaginal microbiomes based on both composition and functional potential.

RESULTS

MgCSTs are categories of microbiomes classified using taxonomy and the functional potential encoded in their metagenomes. MgCSTs reflect unique combinations of metagenomic subspecies (mgSs), which are assemblages of bacterial strains of the same species, within a microbiome. We demonstrate that mgCSTs are associated with demographics such as age and race, as well as vaginal pH and Gram stain assessment of vaginal smears. Importantly, these associations varied between mgCSTs predominated by the same bacterial species. A subset of mgCSTs, including three of the six predominated by Gardnerella vaginalis mgSs, as well as mgSs of L. iners, were associated with a greater likelihood of bacterial vaginosis diagnosed by Amsel clinical criteria. This L. iners mgSs, among other functional features, encoded enhanced genetic capabilities for epithelial cell attachment that could facilitate cytotoxin-mediated cell lysis. Finally, we report a mgSs and mgCST classifier for which source code is provided and may be adapted for use by the microbiome research community.

CONCLUSIONS

MgCSTs are a novel and easily implemented approach to reduce the dimension of complex metagenomic datasets while maintaining their functional uniqueness. MgCSTs enable the investigation of multiple strains of the same species and the functional diversity in that species. Future investigations of functional diversity may be key to unraveling the pathways by which the vaginal microbiome modulates the protection of the genital tract. Importantly, our findings support the hypothesis that functional differences between vaginal microbiomes, including those that may look compositionally similar, are critical considerations in vaginal health. Ultimately, mgCSTs may lead to novel hypotheses concerning the role of the vaginal microbiome in promoting health and disease, and identify targets for novel prognostic, diagnostic, and therapeutic strategies to improve women's genital health. Video Abstract.

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.

Vaginal Microbial Network Analysis Reveals Novel Taxa Relationships among Adolescent and Young Women with Incident Sexually Transmitted Infection Compared with Those Remaining Persistently Negative over a 30-Month Period

A non-optimal vaginal microbiome (VMB) is typically diverse with a paucity of Lactobacillus crispatus and is often associated with bacterial vaginosis (BV) and sexually transmitted infections (STIs). Although compositional characterization of the VMB is well-characterized, especially for BV, knowledge remains limited on how different groups of bacteria relate to incident STIs, especially among adolescents. In this study, we compared the VMB (measured via 16S ribosomal RNA gene amplicon sequencing) of Kenyan secondary school girls with incident STIs (composite of chlamydia, gonorrhea, and trichomoniasis) to those who remained persistently negative for STIs and BV over 30 months of follow-up. We applied microbial network analysis to identify key taxa (i.e., those with the greatest connectedness in terms of linkages to other taxa), as measured by betweenness and eigenvector centralities, and sub-groups of clustered taxa. VMB networks of those who remained persistently negative reflected greater connectedness compared to the VMB from participants with STI. Taxa with the highest centralities were not correlated with relative abundance and differed between those with and without STI. Subject-level analyses indicated that sociodemographic (e.g., age and socioeconomic status) and behavioral (e.g., sexual activity) factors contribute to microbial network structure and may be of relevance when designing interventions to improve VMB health.

Genital tract microbiome dynamics are associated with time of Chlamydia infection in mice

We have previously shown that the time of Chlamydia infection was crucial in determining the chlamydial infectivity and pathogenesis. This study aims to determine whether the time of Chlamydia infection affects the genital tract microbiome. This study analyzed mice vaginal, uterine, and ovary/oviduct microbiome with and without Chlamydia infection. The mice were infected with Chlamydia at either 10:00 am (ZT3) or 10:00 pm (ZT15). The results showed that mice infected at ZT3 had higher Chlamydia infectivity than those infected at ZT15. There was more variation in the compositional complexity of the vaginal microbiome (alpha diversity) of mice infected at ZT3 than those mice infected at ZT15 throughout the infection within each treatment group, with both Shannon and Simpson diversity index values decreased over time. The analysis of samples collected four weeks post-infection showed that there were significant taxonomical differences (beta diversity) between different parts of the genital tract-vagina, uterus, and ovary/oviduct-and this difference was associated with the time of infection. Firmicutes and Proteobacteria were the most abundant phyla within the microbiome in all three genital tract regions for all the samples collected during this experiment. Additionally, Firmicutes was the dominant phylum in the uterine microbiome of ZT3 Chlamydia infected mice. The results show that the time of infection is associated with the microbial dynamics in the genital tract. And this association is more robust in the upper genital tract than in the vagina. This result implies that more emphasis should be placed on understanding the changes in the microbial dynamics of the upper genital tract over the course of infection.

High-resolution functional description of vaginal microbiomes in health and disease

Background

A Lactobacillus-dominated vaginal microbiome provides the first line of defense against numerous adverse genital tract health outcomes. However, there is limited understanding of the mechanisms by which the vaginal microbiome modulates protection, as prior work mostly described its composition through morphologic assessment and marker gene sequencing methods that do not capture functional information. To address this limitation, we developed metagenomic community state types (mgCSTs) which uses metagenomic sequences to describe and define vaginal microbiomes based on both composition and function.

Results

MgCSTs are categories of microbiomes classified using taxonomy and the functional potential encoded in their metagenomes. MgCSTs reflect unique combinations of metagenomic subspecies (mgSs), which are assemblages of bacterial strains of the same species, within a microbiome. We demonstrate that mgCSTs are associated with demographics such as age and race, as well as vaginal pH and Gram stain assessment of vaginal smears. Importantly, these associations varied between mgCSTs predominated by the same bacterial species. A subset of mgCSTs, including three of the six predominated by Gardnerella mgSs, as well as a mgSs of L. iners, were associated with a greater likelihood of Amsel bacterial vaginosis diagnosis. This L. iners mgSs, among other functional features, encoded enhanced genetic capabilities for epithelial cell attachment that could facilitate cytotoxin-mediated cell lysis. Finally, we report a mgSs and mgCST classifier as an easily applied, standardized method for use by the microbiome research community.

Conclusions

MgCSTs are a novel and easily implemented approach to reducing the dimension of complex metagenomic datasets, while maintaining their functional uniqueness. MgCSTs enable investigation of multiple strains of the same species and the functional diversity in that species. Future investigations of functional diversity may be key to unraveling the pathways by which the vaginal microbiome modulates protection to the genital tract. Importantly, our findings support the hypothesis that functional differences between vaginal microbiomes, including those that may look compositionally similar, are critical considerations in vaginal health. Ultimately, mgCSTs may lead to novel hypotheses concerning the role of the vaginal microbiome in promoting health and disease, and identify targets for novel prognostic, diagnostic, and therapeutic strategies to improve women's genital health.

Female reproductive tract-organ axes

The female reproductive tract (FRT) and remote/versatile organs in the body share bidirectional communication. In this review, we discuss the framework of the "FRT-organ axes." Each axis, namely, the vagina-gut axis, uterus-gut axis, ovary-gut axis, vagina-bladder axis, vagina-oral axis, uterus-oral axis, vagina-brain axis, uterus-brain axis, and vagina-joint axis, is comprehensively discussed separately. Each axis could be involved in the pathogenesis of not only gynecological diseases but also diseases occurring apart from the FRT. Although the microbiota is clearly a key player in the FRT-organ axes, more quantitative insight into the homeostasis of the microbiota could be provided by host function measurements rather than current microbe-centric approaches. Therefore, investigation of the FRT-organ axes would provide us with a multicentric approach, including immune, neural, endocrine, and metabolic aspects, for understanding the homeostatic mechanism of women's bodies. The framework of the FRT-organ axes could also provide insights into finding new therapeutic approaches to maintain women's health.

Gut dysbiosis contributes to chlamydial induction of hydrosalpinx in the upper genital tract

Chlamydia trachomatis is one of the most common sexually infections that cause infertility, and its genital infection induces tubal adhesion and hydrosalpinx. Intravaginal Chlamydia muridarum infection in mice can induce hydrosalpinx in the upper genital tract and it has been used for studying C. trachomatis pathogenicity. DBA2/J strain mice were known to be resistant to the chlamydial induction of hydrosalpinx. In this study, we took advantage of this feature of DBA2/J mice to evaluate the role of antibiotic induced dysbiosis in chlamydial pathogenicity. Antibiotics (vancomycin and gentamicin) were orally administrated to induce dysbiosis in the gut of DBA2/J mice. The mice with or without antibiotic treatment were evaluated for gut and genital dysbiosis and then intravaginally challenged by C. muridarum. Chlamydial burden was tested and genital pathologies were evaluated. We found that oral antibiotics significantly enhanced chlamydial induction of genital hydrosalpinx. And the antibiotic treatment induced severe dysbiosis in the GI tract, including significantly reduced fecal DNA and increased ratios of firmicutes over bacteroidetes. The oral antibiotic did not alter chlamydial infection or microbiota in the mouse genital tracts. Our study showed that the oral antibiotics-enhanced hydrosalpinx correlated with dysbiosis in gut, providing the evidence for associating gut microbiome with chlamydial genital pathogenicity.

Optimal sampling and analysis methods for clinical diagnostics of vaginal microbiome

Next-generation sequencing-based microbiological analysis is a complex way to profile vaginal microbiome samples since each step affects the results gained. Methodologies for sample collection lack golden standards. We compared Puritan DNA/RNA swab (PS) and Copan FLOQ swab (CS) and provided consistent and reliable microbiome profiles analyzed by 16S rRNA gene sequencing. We collected two consecutive vaginal samples utilizing PS with room temperature storing and CS with instant freezing from 26 women. Variable region 4 of bacterial 16S rRNA gene was amplified with single PCR by custom-designed dual-indexed primers and sequenced with Illumina MiSeq system. Read quality control, operational taxonomic unit tables, and alpha and beta diversities analysis were performed, and community richness, diversity, and evenness were evaluated and compared between the two samplings and tests. Nineteen sample pairs produced detectable, intact DNA during the extraction protocol and/or further microbial profiles. Alpha bacterial diversity indices were independent on the collection protocol. No significant statistical differences were found in the measured beta diversity metrics between the collection methods. Of the women, 43% had Lactobacillus-dominated vaginal microbiome profile despite of collection method. Previously reported important vaginal microbiome phyla Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Proteobacteria were present in the sample set although their relative abundances varied among individuals. PS and CS enable constant vaginal microbiota sampling. The PS method with no need for instant freezing is suitable for on-site collections at clinics. Furthermore, it seems to be possible to take two samples instead of one with constant microbiological results.

Updates on Group B Streptococcus Infection in the Field of Obstetrics and Gynecology

Group B Streptococcus (GBS, Streptococcus agalactiae) is a Gram-positive bacterium that is commonly found in the gastrointestinal and urogenital tracts. However, its colonization during pregnancy is an important cause of maternal and neonatal morbidity and mortality worldwide. Herein, we specifically looked at GBS in relation to the field of Obstetrics (OB) along with the field of Gynecology (GY). In this review, based on the clinical significance of GBS in the field of OBGY, topics of how GBS is being detected, treated, and should be prevented are addressed.

Vaginal microbiome: considerations for reproductive health

The microbial communities are an indispensable part of the human defense system and coexist with humans as symbionts, contributing to the metabolic functions and immune defense against pathogens. An ecologically stable vaginal microbiota is dominated by Lactobacillus species, which plays an important role in the prevention of genital infections by controlling the vaginal pH, reducing glycogen to lactic acid, and stimulating bacteriocins and hydrogen peroxide. In contrast, an abnormal vaginal microbial composition is associated with an increased risk of bacterial vaginosis, trichomoniasis, sexually transmitted diseases, preterm labor and other birth defects. This microbial diversity is affected by race, ethnicity, pregnancy, hormonal changes, sexual activities, hygiene practices and other conditions. In the present review, we discuss the changes in the microbial community of the vaginal region at different stages of a female's life cycle and its influence on her reproductive health and pathological conditions.

Recurrent urinary tract infection and estrogen shape the taxonomic ecology and function of the postmenopausal urogenital microbiome

Postmenopausal women are severely affected by recurrent urinary tract infection (rUTI). The urogenital microbiome is a key component of the urinary environment. However, changes in the urogenital microbiome underlying rUTI susceptibility are unknown. Here, we perform shotgun metagenomics and advanced culture on urine from a controlled cohort of postmenopausal women to identify urogenital microbiome compositional and function changes linked to rUTI susceptibility. We identify candidate taxonomic biomarkers of rUTI susceptibility in postmenopausal women and an enrichment of lactobacilli in postmenopausal women taking estrogen hormone therapy. We find robust correlations between Bifidobacterium and Lactobacillus and urinary estrogens in women without urinary tract infection (UTI) history. Functional analyses reveal distinct metabolic and antimicrobial resistance gene (ARG) signatures associated with rUTI. Importantly, we find that ARGs are enriched in the urogenital microbiomes of women with rUTI history independent of current UTI status. Our data suggest that rUTI and estrogen shape the urogenital microbiome in postmenopausal women.

Improving analysis of the vaginal microbiota of women undergoing assisted reproduction using nanopore sequencing

PURPOSE

Subclinical alterations of the vaginal microbiome have been described to be associated with female infertility and may serve as predictors for failure of in vitro fertilization treatment. While large prospective studies to delineate the role of microbial composition are warranted, integrating microbiome information into clinical management depends on economical and practical feasibility, specifically on a short duration from sampling to final results. The currently most used method for microbiota analysis is either metagenomics sequencing or amplicon-based microbiota analysis using second-generation methods such as sequencing-by-synthesis approaches (Illumina), which is both expensive and time-consuming. Thus, additional approaches are warranted to accelerate the usability of the microbiome as a marker in clinical praxis.

METHODS

Herein, we used a set of ten selected vaginal swabs from women undergoing assisted reproduction, comparing and performing critical optimization of nanopore-based microbiota analysis with the results from MiSeq-based data as a quality reference.

RESULTS

The analyzed samples carried varying community compositions, as shown by amplicon-based analysis of the V3V4 region of the bacterial 16S rRNA gene by MiSeq sequencing. Using a stepwise procedure to optimize adaptation, we show that a close approximation of the microbial composition can be achieved within a reduced time frame and at a minimum of costs using nanopore sequencing.

CONCLUSIONS

Our work highlights the potential of a nanopore-based methodical setup to support the feasibility of interventional studies and contribute to the development of microbiome-based clinical decision-making in assisted reproduction.

In-depth insights into cervicovaginal microbial communities and hrHPV infections using high-resolution microbiome profiling

The cervicovaginal microbiome (CVM) correlates with women's cervical health, and variations in its composition are associated with high-risk human papillomavirus (hrHPV) infection outcomes. Cervicovaginal microbes have been grouped into five community state types (CSTs) based on microbial community composition and abundance. However, studying the impact of CSTs in health and disease is challenging because the current sequencing technologies have limited confident discrimination between closely related and yet functionally different bacterial species. Circular probe-based RNA sequencing (ciRNAseq) achieves high-resolution microbiome profiling and therefore provides in-depth and unambiguous knowledge about the composition of the CVM. Based on ciRNAseq profiling of a large cohort of cervical smears (n = 541), we here define subgroups of CSTs I, III, and IV based on intra-CST differences with respect to abundances of Lactobacillus acidophilus (CSTs I-A vs. I-B and CSTs III-A vs. III-B), Lactobacillus iners (CSTs I-A vs. I-B and CSTs III-A vs. III-B), and Megasphaera genomosp type 1 (CSTs IV-A vs. IV-B). Our results further support the existence of subgroups of CST IV-C that are dominant for non-Lactobacillus species and have intermediate microbial diversity. We also show that CST V is associated with uninfected conditions, and CST IV-A associates with hrHPV-induced cervical disease. In conclusion, we characterized new subdivisions of cervicovaginal CSTs, which may further advance our understanding of women's cervical health and hrHPV-related progression to disease.

Peptoniphilus indolicus infection in a pregnant woman: a case report

BACKGROUND

Peptoniphilus indolicus belongs is a gram-positive anaerobic coccus (GPAC), which can cause bacterial vaginitis. However, only a few studies have reported severe infection of P. indolicus. This study presented the first case of severe infection of P. indolicus during pregnancy. It aimed to help to fill the gap in the literature, find out the factors that accelerate infection and discuss the significance of the GPAC test.

CASE PRESENTATION

A 35-year-old woman was admitted due to unbearable abdominal pain with dilation of the cervical opening at 22+ weeks of gestation. A blood test revealed electrolyte disturbance and hypoproteinemia. A day before admission, the patient developed pain in the lower abdomen accompanied by yellow-green vaginal discharge. Two hours after admission, the patient suddenly presented with hyperpyrexia and chills. Timely and adequate antibiotic and cooling treatments were administered. After 14 h, the patient again developed chills that lasted for approximately 20 min, accompanied by uterine contractions and membrane rupture. After 3 h, she had a miscarriage and rapidly developed septic shock. She was transferred to the intensive care unit for further infection control, shock correction, and circulatory stabilization. The cultures of blood, secretion specimen, and amniotic fluid indicated P. indolicus infection using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, an advanced tool for bacterial species identification.

CONCLUSIONS

P. indolicus is an opportunistic pathogen in pregnant women. Poor physical conditions and pregnancy may accelerate disease progression and lead to severe inflammation.

The Urogenital System’s Role in Diseases: A Synopsis

Simple Summary

The urinary tract microbiome has come under a lot of scrutiny, and this has led to the rejection of the pre-established concept of sterility in the urinary bladder. Microbial communities in the urinary tract have been implicated in the maintenance of health. Thus, alterations in their composition have also been associated with different urinary pathologies, such as urinary tract infections. For that reason, tackling the urinary microbiome of healthy individuals, as well as its involvement in disease through the proliferation of opportunistic pathogens, could open a potential field of study, leading to new insights into prevention, diagnosis, and treatment strategies for different diseases.

Abstract

The human microbiota contains ten times more microbial cells than human cells contained by the human body, constituting a larger genetic material than the human genome itself. Emerging studies have shown that these microorganisms represent a critical determinant in human health and disease, and the use of probiotic products as potential therapeutic interventions to modulate homeostasis and treat disease is being explored. The gut is a niche for the largest proportion of the human microbiota with myriad studies suggesting a strong link between the gut microbiota composition and disease development throughout the body. More specifically, there is mounting evidence on the relevance of gut microbiota dysbiosis in the development of urinary tract disease including urinary tract infections (UTIs), chronic kidney disease, and kidney stones. Fewer emerging reports, however, are suggesting that the urinary tract, which has long been considered ‘sterile’, also houses its unique microbiota that might have an important role in urologic health and disease. The implications of this new paradigm could potentially change the therapeutic perspective in urological disease.

Distinct gut and vaginal microbiota profile in women with recurrent implantation failure and unexplained infertility

BACKGROUND

Female reproductive tract dysbiosis impacts implantation. However, whether gut dysbiosis influences implantation failure and whether it accompanies reproductive tract dysbiosis remains scantly explored. Herein, we examined the gut-vaginal microbiota axis in infertile women.

METHODS

We recruited 11 fertile women as the controls, and a cohort of 20 infertile women, 10 of whom had recurrent implantation failure (RIF), and another 10 had unexplained infertility (UE). Using amplicon sequencing, which employs PCR to create sequences of DNA called amplicon, we compared the diversity, structure, and composition of faecal and vaginal bacteria of the controls with that of the infertile cohort. Of note, we could only sequence 8 vaginal samples in each group (n = 24/31).

RESULT

Compared with the controls, α-diversity and β-diversity of the gut bacteria among the infertile groups differed significantly (p < 0.05). Taxa analysis revealed enrichment of Gram-positive bacteria in the RIF group, whereas Gram-negative bacteria were relatively abundant in the UE group. Strikingly, mucus-producing genera declined in the infertile cohort (p < 0.05). Hungatella, associated with trimethylamine N-oxide (TMAO) production, were enriched in the infertile cohort (p < 0.05). Vaginal microbiota was dominated by the genus Lactobacillus, with Lactobacillus iners AB-1 being the most abundant species across the groups. Compared with the infertile cohort, overgrowth of anaerobic bacteria, associated with vaginal dysbiosis, such as Leptotrichia and Snethia, occurred in the controls.

CONCLUSION

The gut microbiota had little influence on the vaginal microbiota. Gut dysbiosis and vaginal eubiosis occurred in the infertile women, whereas the opposite trend occurred in the controls.

Towards a deeper understanding of the vaginal microbiota

The human vaginal microbiota is a critical determinant of vaginal health. These communities live in close association with the vaginal epithelium and rely on host tissues for resources. Although often dominated by lactobacilli, the vaginal microbiota is also frequently composed of a collection of facultative and obligate anaerobes. The prevalence of these communities with a paucity of Lactobacillus species varies among women, and epidemiological studies have associated them with an increased risk of adverse health outcomes. The mechanisms that drive these associations have yet to be described in detail, with few studies establishing causative relationships. Here, we review our current understanding of the vaginal microbiota and its connection with host health. We centre our discussion around the biology of the vaginal microbiota when Lactobacillus species are dominant versus when they are not, including host factors that are implicated in shaping these microbial communities and the resulting adverse health outcomes. We discuss current approaches to modulate the vaginal microbiota, including probiotics and vaginal microbiome transplants, and argue that new model systems of the cervicovaginal environment that incorporate the vaginal microbiota are needed to progress from association to mechanism and this will prove invaluable for future research.

Image classification of vaginal microecology detection based on gabor texture and LSTM model

BACKGROUND

Gynecological diseases threaten women's health, and vaginal microecological testing is a common method for detecting gynecological diseases. Efficient and accurate microecological testing methods have always been the goal pursued by gynecologists.

OBJECTIVE

In order to automatically identify different types of microbial images in vaginal micromorphology detection, this paper proposes a vaginal microecological image recognition method based on Gabor texture analysis combined with long and short-term memory network (LSTM) model.

METHOD

Firstly, we denoise the microecological morphological im-ages, which selects the area of interest and sets the label of the microorganism according to the doctors label. Secondly, texture analysis is carried out for the region of interest, which uses Gabor filters with 8 directions and 5 scales to filter the region of interest to extract the texture features on the image. Comparing the differences between different microbial image features, and screening suitable features to reduce the number of features. Then, we design an LSTM model to analyze the relationship of image features in different categories of microorganisms. Finally, we use the full connection layer and Softmax function to realize the automatic recognition of different microbial images.

RESULTS

The experimental results show that the image classification accuracy of 8 common microorganisms is 81.26%.

CONCLUSION

Texture analysis combined with LSTM network strategy can identify different kinds of vaginal micro ecological images. Gabor-LSTM model has better classification effect on imbalanced data sets.

Novel high-resolution targeted sequencing of the cervicovaginal microbiome

BACKGROUND

The cervicovaginal microbiome (CVM) plays a significant role in women's cervical health and disease. Microbial alterations at the species level and characteristic community state types (CST) have been associated with acquisition and persistence of high-risk human papillomavirus (hrHPV) infections that may result in progression of cervical lesions to malignancy. Current sequencing methods, especially most commonly used multiplex 16S rRNA gene sequencing, struggle to fully clarify these changes because they generally fail to provide sufficient taxonomic resolution to adequately perform species-level associative studies. To improve CVM species designation, we designed a novel sequencing tool targeting microbes at the species taxonomic rank and examined its potential for profiling the CVM.

RESULTS

We introduce an accessible and practical circular probe-based RNA sequencing (CiRNAseq) technology with the potential to profile and quantify the CVM. In vitro and in silico validations demonstrate that CiRNAseq can distinctively detect species in a mock mixed microbial environment, with the output data reflecting its ability to estimate microbes' abundance. Moreover, compared to 16S rRNA gene sequencing, CiRNAseq provides equivalent results but with improved sequencing sensitivity. Analyses of a cohort of cervical smears from hrHPV-negative women versus hrHPV-positive women with high-grade cervical intraepithelial neoplasia confirmed known differences in CST occurring in the CVM of women with hrHPV-induced lesions. The technique also revealed variations in microbial diversity and abundance in the CVM of hrHPV-positive women when compared to hrHPV-negative women.

CONCLUSIONS

CiRNAseq is a promising tool for studying the interplay between the CVM and hrHPV in cervical carcinogenesis. This technology could provide a better understanding of cervicovaginal CST and microbial species during health and disease, prompting the discovery of biomarkers, additional to hrHPV, that can help detect high-grade cervical lesions.

The role of gut and genital microbiota and the estrobolome in endometriosis, infertility and chronic pelvic pain

BACKGROUND

Endometriosis is a chronic, burdensome condition that is historically understudied. Consequently, there is a lack of understanding of the etiology of the disease and its associated symptoms, including infertility and chronic pelvic pain (CPP). Endometriosis development is influenced by estrogen metabolism and inflammation, which are modulated by several factors including the microbiome and the estrobolome (the collection of genes encoding estrogen-metabolizing enzymes in the gut microbiome). Therefore, there is increasing interest in understanding the role of microbiota in endometriosis etiology.

OBJECTIVE AND RATIONALE

To date, there is no cure for endometriosis and treatment options often are ineffective. This manuscript will review the potential relationship between the microbiome and endometriosis, infertility and CPP and highlight the available data on the microbiome in relation to endometriosis and its related symptoms. The overarching goal of this manuscript is to inform future microbiome research that will lead to a deeper understanding of the etiology of the disease and possible diagnostic modalities and treatments. The potential impact of the microbiome on estrogen regulation modulated by the estrobolome, as well as inflammation and other endometriosis-promoting mechanisms within the genital tract, will be reviewed. The methodological limitations of microbiome-related studies will be critically assessed to provide improved guidelines for future microbiome and clinical studies.

SEARCH METHODS

PubMed databases were searched using the following keywords: endometriosis AND microbiome, infertility AND microbiome, pelvic pain AND microbiome, IVF (in-vitro fertilization) AND microbiome, endometriosis AND infertility. Clinical and preclinical animal trials that were eligible for review, and related to microbiome and endometriosis, infertility or CPP were included. All available manuscripts were published in 2002-2021.

OUTCOMES

In total, 28 clinical and 6 animal studies were included in the review. In both human and animal studies, bacteria were enriched in endometriosis groups, although there was no clear consensus on specific microbiota compositions that were associated with endometriosis, and no studies included infertility or CPP with endometriosis. However, bacterial vaginosis-associated bacteria and Lactobacillus depletion in the cervicovaginal microbiome were associated with endometriosis and infertility in the majority (23/28) of studies. Interpretation of endometrial studies is limited owing to a variety of methodological factors, discussed in this review. In addition, metadata outlining antibiotic usage, age, race/ethnicity, menopausal status and timing of sample collection in relation to diagnosis of endometriosis was not consistently reported. Animal studies (6/6) support a bidirectional relationship between the gut microbiota and endometriosis onset and progression.

WIDER IMPLICATIONS

There is evidence that a dysbiotic gut or genital microbiota is associated with multiple gynecologic conditions, with mounting data supporting an association between the microbiome and endometriosis and infertility. These microbiomes likely play a role in the gut-brain axis, which further supports a putative association with the spectrum of symptoms associated with endometriosis, including infertility and CPP. Collectively, this review highlights the demand for more rigorous and transparent methodology and controls, consistency across the field, and inclusion of key demographic and clinical characteristics of disease and comparison participants. Rigorous study designs will allow for a better understanding of the potential role of the microbiome in endometriosis etiology and the relationship to other disorders of the female reproductive tract.

Does probiotics work for bacterial vaginosis and vulvovaginal candidiasis

The different Lactobacillus strains of probiotics have been applied to the treatment and prevention of bacterial vaginosis and vulvovaginal candidiasis. The experimental data demonstrated that it works well via reducing the number of harmful bacteria, maintaining the acidic microenvironment, inhibiting the immune response, and so on, to restore the vaginal microecology. However, the clinical data indicated that it is not sufficient to support the use of probiotics in the intervention of vulvovaginal candidiasis rather than bacterial vaginosis. Hunting for novel probiotic strains and uncovering the precise mechanism of probiotics, especially with the new concept gut-vagina axis, to maintain the homeostasis of vaginal microbiota should be a great challenge in the future.

The impact of the female genital tract microbiome in women health and reproduction: a review

PURPOSE

The aim of this review is to gather the available research focusing on female genital tract (FGT) microbiome. Research question focuses in decipher which is the role of FGT microbiota in eubiosis, assisted reproduction techniques (ARTs), and gynaecological disorders, and how microbiome could be utilised to improve reproduction outcomes and to treat fertility issues.

METHODS

PubMed was searched for articles in English from January 2004 to April 2021 for "genital tract microbiota and reproduction", "endometrial microbiome", "microbiome and reproduction" and "microbiota and infertility". Manual search of the references within the resulting articles was performed.

RESULTS

Current knowledge confirms predominance of Lactobacillus species, both in vagina and endometrium, whereas higher variability of species is both found in fallopian tubes and ovaries. Microbial signature linked to different disorders such endometriosis, bacterial vaginosis, and gynaecological cancers are described. Broadly, low variability of species and Lactobacillus abundance within the FGT is associated with better reproductive and ART outcomes.

CONCLUSION

Further research regarding FGT microbiome configuration needs to be done in order to establish a more precise link between microbiota and eubiosis or dysbiosis. Detection of bacterial species related with poor reproductive outcomes, infertility or gynaecological diseases could shape new tools for their diagnosis and treatment, as well as resources to assess the pregnancy prognosis based on endometrial microbiota. Data available suggest future research protocols should be standardised, and it needs to include the interplay among microbiome, virome and mycobiome, and the effect of antibiotics or probiotics on the microbiome shifts.

Composition of the vaginal microbiota during pregnancy in women living in sub-Saharan Africa: a PRISMA-compliant review

BACKGROUND

The vaginal microbiota (VMB) are the set of microorganisms residing in the human vagina. During pregnancy, their composition is Lactobacillus-dominant in most Caucasian women. Previous studies suggest that the VMB of women with African ancestry is more likely to be non-Lactobacillus dominant (dysbiotic) compared to other populations, and possibly relate to the high incidence of pregnancy complications, such as preterm birth. This work reviewed the literature on VMB composition in pregnant women from sub-Saharan Africa.

METHODS

A search was conducted in PubMed and Embase databases following PRISMA guidelines. Observational and intervention studies analysing VMB communities from sub-Saharan African pregnant women using molecular techniques were included.

RESULTS

Ten studies performed in seven sub-Saharan African countries were identified. They independently showed that Lactobacillus-dominant VMB (particularly L. iners or L. crispatus) or VMB containing Lactobacilli are the most prevalent, followed by a more diverse anaerobe-dominant VMB, in the studied populations. The majority of pregnant women with a sexually-transmitted infection had a Lactobacillus-dominant VMB, but with a significantly higher presence of anaerobic species.

CONCLUSION

In agreement with studies performed in other populations, Lactobacillus species are the most prevalent VMB species during pregnancy in sub-Saharan African women. The frequency of diverse anaerobe-dominant VMB is high in these populations. In Africa, studies on VMB in pregnancy are scant, heterogeneous in methodology, and knowledge remains limited. More insights on VMB composition and their possible sequalae among these populations is needed.

Microbiota Management for Effective Disease Suppression: A Systematic Comparison between Soil and Mammals Gut

Both soil and the human gut support vast microbial biodiversity, in which the microbiota plays critical roles in regulating harmful organisms. However, the functional link between microbiota taxonomic compositions and disease suppression has not been explained yet. Here, we provide an overview of pathogen regulation in soil and mammals gut, highlighting the differences and the similarities between the two systems. First, we provide a review of the ecological mechanisms underlying the regulation of soil and pathogens, as well as the link between disease suppression and soil health. Particular emphasis is thus given to clarifying how soil and the gut microbiota are associated with organic amendment and the human diet, respectively. Moreover, we provide several insights into the importance of organic amendment and diet composition in shaping beneficial microbiota as an efficient way to support crop productivity and human health. This review also discusses novel ways to functionally characterize organic amendments and the proper operational combining of such materials with beneficial microbes for stirring suppressive microbiota against pathogens. Furthermore, specific examples are given to describe how agricultural management practices, including the use of antibiotics and fumigants, hinder disease suppression by disrupting microbiota structure, and the potentiality of entire microbiome transplant. We conclude by discussing general strategies to promote soil microbiota biodiversity, the connection with plant yield and health, and their possible integration through a “One Health” framework.

Veillonellaceae family members uniquely alter the cervical metabolic microenvironment in a human three-dimensional epithelial model

Bacterial vaginosis (BV) is a gynecologic disorder characterized by a shift in cervicovaginal microbiota from Lactobacillus spp. dominance to a polymicrobial biofilm composed of diverse anaerobes. We utilized a well-characterized human three-dimensional cervical epithelial cell model in conjunction with untargeted metabolomics and immunoproteomics analyses to determine the immunometabolic contribution of three members of the Veillonellaceae family: Veillonella atypica, Veillonella montpellierensis and Megasphaera micronuciformis at this site. We found that Veillonella spp. infections induced significant elevation of polyamines. M. micronuciformis infections significantly increased soluble inflammatory mediators, induced moderate levels of cell cytotoxicity, and accumulation of cell membrane lipids relative to Veillonella spp. Notably, both V. atypica and V. montpellierensis infections resulted in consumption of lactate, a key metabolite linked to gynecologic and reproductive health. Collectively our approach and data provide unique insights into the specific contributions of Veillonellaceae members to the pathogenesis of BV and women's health.

The promising biological role of postbiotics derived from probiotic Lactobacillus species in reproductive health

Recent investigations have meaningfully developed our knowledge of the features of the reproductive microbiome/metabolome profile and their relations with host responses to offer an optimal milieu for the development of the embryo during the peri-implantation period and throughout pregnancy. In this context, the establishment of homeostatic circumstances in the Female Reproductive Tract (FRT), in various physiological periods, is a significant challenge, which appears the application of postbiotics can facilitate the achievement of this goal. So, currently, scientific literature confirms that postbiotics due to their antimicrobial, antiviral, and immunomodulatory properties can be considered as a novel biotherapeutic approach. Future investigation in this field will shed more translational mechanistic understanding of the interaction of the postbiotics derived from vaginal Lactobacilli with females' health and reproduction.

Implications of the vaginal microbiome and potential restorative strategies on maternal health: a narrative review

The vaginal microbiome undergoes dramatic shifts before and throughout pregnancy. Although the genetic and environmental factors that regulate the vaginal microbiome have yet to be fully elucidated, high-throughput sequencing has provided an unprecedented opportunity to interrogate the vaginal microbiome as a potential source of next-generation therapeutics. Accumulating data demonstrates that vaginal health during pregnancy includes commensal bacteria such as Lactobacillus that serve to reduce pH and prevent pathogenic invasion. Vaginal microbes have been studied as contributors to several conditions occurring before and during pregnancy, and an emerging topic in women's health is finding ways to alter and restore the vaginal microbiome. Among these restorations, perhaps the most significant effect could be preterm labor (PTL) prevention. Since bacterial vaginosis (BV) is known to increase risk of PTL, and vaginal and oral probiotics are effective as supplemental treatments for BV prevention, a potential therapeutic benefit exists for pregnant women at risk of PTL. A new method of restoration, vaginal microbiome transplants (VMTs) involves transfer of one women's cervicovaginal secretions to another. New studies investigating recurrent BV will determine if VMTs can safely establish a healthy Lactobacillus-dominant vaginal microbiome. In most cases, caution must be taken in attributing a disease state and vaginal dysbiosis with a causal relationship, since the underlying reason for dysbiosis is usually unknown. This review focuses on the impact of vaginal microflora on maternal outcomes before and during pregnancy, including PTL, gestational diabetes, preeclampsia, and infertility. It then reviews the clinical evidence focused on vaginal restoration strategies, including VMTs.

Pre- and postmenopausal women have different core urinary microbiota

Recent studies suggest that alterations in the female urinary microbiota is associated to development of bladder disease. However, the normal microbiota composition and variation in healthy women are poorly described. Moreover, the effects of hormonal changes on microbiota during menopause is not well understood. The aim of our study was to investigate the urinary microbiota in healthy pre- and postmenopausal women without urinary tract symptoms. Microbiota composition in catheterized urine samples was mapped using 16S rRNA gene sequencing. In total, 41 premenopausal and 42 postmenopausal women were initially included. Samples with first PCR amplification concentration below level of the negative control were excluded, resulting in 34 premenopausal and 20 postmenopausal women included in data analysis. Urine from postmenopausal women showed significantly higher alpha diversity compared to premenopausal women. Lactobacillus was the most abundant bacteria in both groups, however the relative abundance of Lactobacillus accounted for 77.8% in premenopausal versus 42.0% in postmenopausal women. In conclusion, urine from premenopausal mostly presented with Lactobacillus dominated urotypes, whereas urine from postmenopausal women presented a more diverse urinary microbiota with higher abundance of the genera Gardnerella and Prevotella. The clinical and pathophysiological implications of this difference remain to be elucidated.

Role of Lactobacillus in Female Infertility Via Modulating Sperm Agglutination and Immobilization

Infertility has become a common problem in recent decades. The pathogenesis of infertility is variable, but microbiological factors account for a large proportion of it. Dysbiosis of vaginal microbiota is reportedly associated with female infertility, but the influence of normal vaginal microbiota on infertility is unclear. In this review, we summarize the physiological characteristics of the vaginal tract and vaginal microbiota communities. We mainly focus on the bacterial adherence of vaginal Lactobacillus species. Given that the adherent effect plays a crucial role in the colonization of bacteria, we hypothesize that the adherent effect of vaginal Lactobacillus may also influence the fertility of the host. We also analyze the agglutination and immobilization effects of other bacteria, especially Escherichia coli, on ejaculated spermatozoa, and speculate on the possible effects of normal vaginal microbiota on female fertility.

The Role of Gut, Vaginal, and Urinary Microbiome in Urinary Tract Infections: From Bench to Bedside

The current paradigm of urinary tract infection (UTI) pathogenesis takes into account the contamination of the periurethral space by specific uropathogens residing in the gut, which is followed by urethral colonization and pathogen ascension to the urinary bladder. Consequently, studying the relationship between gut microbiota and the subsequent development of bacteriuria and UTI represents an important field of research. However, the well-established diagnostic and therapeutic paradigm for urinary tract infections (UTIs) has come into question with the discovery of a multifaceted, symbiotic microbiome in the healthy urogenital tract. More specifically, emerging data suggest that vaginal dysbiosis may result in Escherichia coli colonization and prompt recurrent UTIs, while urinary microbiome perturbations may precede the development of UTIs and other pathologic conditions of the urinary system. The question is whether these findings can be exploited for risk reduction and treatment purposes. This review aimed to appraise the three aforementioned specific microbiomes regarding their potential influence on UTI development by focusing on the recent studies in the field and assessing the potential linkages between these different niches, as well as evaluating the state of translational research for novel therapeutic and preventative approaches.

Characteristics of Women and Their Male Sex Partners Predict Bacterial Vaginosis Among a Prospective Cohort of Kenyan Women With Nonoptimal Vaginal Microbiota

BACKGROUND

Up to 50% of women with nonoptimal vaginal microbial community state type (CST) have bacterial vaginosis (BV). Little is known about what distinguishes women with and without BV diagnosis within nonoptimal CST. We identified features of women and their male sex partners associated with BV among women with nonoptimal vaginal CST.

METHODS

In this prospective study, 252 heterosexual couples were observed at 1, 6, and 12 months after baseline. Microbiomes were characterized in cervicovaginal lavage and penile meatal swabs through high-throughput 16s ribosomal RNA gene amplicon sequencing. Nonoptimal CST was defined as CST-IV. Bacterial vaginosis was defined as a Nugent score of 7 to 10. Generalized estimating equation analysis estimated adjusted odds ratios (aORs) for BV among women with nonoptimal CST.

RESULTS

At baseline, women with nonoptimal CST were a median age of 22 years, 44% had BV, 16% had HIV, and 66% had herpes simplex virus (HSV) type 2. Male partners were a median age of 27 years, 12% had HIV, 48% had HSV-2, and 55% were circumcised. Within nonoptimal CST, Sneathia sanguinegens, Prevotella species, Prevotella amnii, and Clostridiales, BV-associated bacteria-2 were statistically significantly enriched in observations with BV. In multivariable generalized estimating equation controlling for CST, HIV, and HSV-2, BV was increased among women with CST-IVA (aOR, 1.91; P = 0.087), HIV (aOR, 2.30; P = 0.051), HSV-2 (aOR, 1.75; P = 0.065), and enrichment of male partner penile taxa: Dialister (aOR, 1.16; P = 0.034), Megasphaera (aOR, 1.22; P = 0.001), and Brevibacterium (aOR, 1.13; P = 0.019).These results provide insights into factors differentiating women with BV among those with nonoptimal vaginal CST. Interrupting the sexual exchange of penile and vaginal taxa may be beneficial for preventing pathologic state of vaginal microbiome.

Next-Generation Sequencing as a Tool to Detect Vaginal Microbiota Disturbances during Pregnancy

The physiological microbiota of the vagina is responsible for providing a protective barrier, but Some factors can disturb the balance in its composition. At that time, the amounts of the genus Lactobacillus decrease, which may lead to the development of infection and severe complications during pregnancy. The aim of the study was the analysis of the bacterial composition of the vagina in 32 Caucasian women at each trimester of pregnancy using the next-generation sequencing method and primers targeting V3-V4 regions. In the studied group, the dominant species were Lactobacillus iners, Lactobacillus gasseri, and Lactobacillusplantarum. Statistically significant differences in the quantitative composition between trimesters were observed in relation to Lactobacillus jensenii,Streptococcus agalactiae, Lactobacillus iners, Gardnerella spp. Out of the 32 patients, 20 demonstrated fluctuations within the genus Lactobacillus, and 9 of them, at different stages of pregnancy, exhibited the presence of potentially pathogenic microbiota, among others: Streptococcus agalactiae, Gardnerella spp., Atopobium vaginae, and Enterococcus faecalis. The composition of the vaginal microbiota during pregnancy was subject to partial changes over trimesters. Although in one-third of the studied patients, both the qualitative and quantitative composition of microbiota was relatively constant, in the remaining patients, physiological and potentially pathogenic fluctuations were distinguished.

Vaginal microbiota and the potential of Lactobacillus derivatives in maintaining vaginal health

Human vagina is colonised by a diverse array of microorganisms that make up the normal microbiota and mycobiota. Lactobacillus is the most frequently isolated microorganism from the healthy human vagina, this includes Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii. These vaginal lactobacilli have been touted to prevent invasion of pathogens by keeping their population in check. However, the disruption of vaginal ecosystem contributes to the overgrowth of pathogens which causes complicated vaginal infections such as bacterial vaginosis (BV), sexually transmitted infections (STIs), and vulvovaginal candidiasis (VVC). Predisposing factors such as menses, pregnancy, sexual practice, uncontrolled usage of antibiotics, and vaginal douching can alter the microbial community. Therefore, the composition of vaginal microbiota serves an important role in determining vagina health. Owing to their Generally Recognised as Safe (GRAS) status, lactobacilli have been widely utilised as one of the alternatives besides conventional antimicrobial treatment against vaginal pathogens for the prevention of chronic vaginitis and the restoration of vaginal ecosystem. In addition, the effectiveness of Lactobacillus as prophylaxis has also been well-founded in long-term administration. This review aimed to highlight the beneficial effects of lactobacilli derivatives (i.e. surface-active molecules) with anti-biofilm, antioxidant, pathogen-inhibition, and immunomodulation activities in developing remedies for vaginal infections. We also discuss the current challenges in the implementation of the use of lactobacilli derivatives in promotion of human health. In the current review, we intend to provide insights for the development of lactobacilli derivatives as a complementary or alternative medicine to conventional probiotic therapy in vaginal health.

Detection of Vaginal Metabolite Changes in Premature Rupture of Membrane Patients in Third Trimester Pregnancy: a Prospective Cohort Study

Premature rupture of membranes (PROM) is usually associated with pregnant and neonatal complications. Most of the PROM cases are caused by ascending asymptomatic genital infection. In China, PROM (15.3%) is more common than spontaneous preterm labor (7.3%) and leads to more adverse pregnancy outcomes. Here, we designed a prospective cohort study to measure the metabolomics changes in vaginal swab samples and explored their potential contribution to PROM. A total of 260 differentially expressed metabolites were identified and further analyzed. In the PROM group, N-acetyl-D-galactosamine and sucrose were downregulated (P = 0.0025, P = 0.0195, respectively), both of which are the upstream metabolites of the glycolysis pathway. Furthermore, estriol 3-sulfate 16-glucuronide (P = 0.0154) and 2-methoxy-17beta-estradiol 3-glucosiduronic acid (P = 0.004), two final metabolites in steroid hormone biosynthesis, were both downregulated in the PROM group. Finally, we found two catechin metabolites (epigallocatechin-7-glucuronide, P = 0.0009; 4'-methyl-epigallocatechin-7-glucuronide, P = 0.01) as well as DL-citrulline (P = 0.0393) were also significantly downregulated in the PROM group compared with the healthy control (HC) group, which are related to important antioxidant and anti-inflammatory activities in the human body. Altogether, metabolite changes in glycolysis, steroid hormone biosynthesis, and antioxidant/anti-inflammatory pathways may contribute to (or be a consequence of) vaginal dysbiosis and PROM. Metabolite pathway analysis is a new and promising approach to further investigate the mechanism of PROM and help prevent its unfavorable pregnant outcomes at a functional level. Trial registration number: ChiCTR2000034721.

Bacterial vaginosis in pregnancy - a storm in the cup of tea

Human vaginal microbiota is dominated by Lactobacillus spp both in the non-pregnant and pregnant state. Bacterial vaginosis (BV) is an imbalance of vaginal microbiota caused by a reduction in the normal lactobacillary bacteria, and a heavy over-growth of mixed anaerobic bacteria. Various clinical (Amsel's Criteria), laboratory (Nugent's score) and molecular diagnostic method (quantitative PCR) are used for diagnosis. BV in pregnancy is associated with increased risk of preterm birth, low birth weight, chorioamnionitis and postpartum endometritis, apart from bothersome vaginal discharge. Antibiotic treatment with metronidazole or clindamycin are effective in eradicating bacterial vaginosis and safe to use in pregnancy. Treatment of bacterial vaginosis has not been shown to improve obstetric outcomes in women at low risk of preterm birth, but may reduce the risk of preterm birth and low birth weight in women at increased risk of preterm birth. Routine screening and treatment is not recommended in low risk women. Test for cure should be performed after treatment. Further research is required on other treatment modalities such as probiotic therapy and microbiota transplantation.

Host Genetic Factors Associated with Vaginal Microbiome Composition in Kenyan Women

Bacterial vaginosis (BV) affects 20% of women worldwide and is associated with adverse reproductive health outcomes and increased risk for HIV. Typically, BV represents a shift in the vaginal microbiome from one that is dominated by Lactobacillus to one that is diverse. Persistent racial differences in BV and diverse vaginal microbiome composition overlap with racial disparities in risks for HIV and sexually transmitted infection, especially among women of African descent. Risk factors for BV and nonoptimal vaginal microbiome include sexual practices, yet racial differences persist when adjusted for behavioral factors, suggesting a host genetic component. Here, we perform a genome-wide association study on vaginal microbiome traits in Kenyan women. Linear regression and logistic regression were performed, adjusting for age and principal components of genetic ancestry, to evaluate the association between Lactobacillus crispatus, Lactobacillus iners, Gardnerella vaginalis, Shannon diversity index, and community state type (CST) with host genetic single nucleotide polymorphisms (SNPs). We identified novel genomic loci associated with the vaginal microbiome traits, though no SNP reached genome-wide significance. During pathway enrichment analysis, Toll-like receptors (TLRs), cytokine production, and other components of innate immune response were associated with L. crispatus, L. iners, and CST. Multiple previously reported genomic loci were replicated, including IL-8 (Shannon, CST), TIRAP (L. iners, Shannon), TLR2 (Shannon, CST), MBL2 (L. iners, G. vaginalis, CST), and MYD88 (L. iners, Shannon). These genetic associations suggest a role for the innate immune system and cell signaling in vaginal microbiome composition and susceptibility to nonoptimal vaginal microbiome.IMPORTANCE Globally, bacterial vaginosis (BV) is a common condition in women. BV is associated with poorer reproductive health outcomes and HIV risk. Typically, BV represents a shift in the vaginal microbiome from one that is dominated by Lactobacillus to one that is diverse. Despite many women having similar exposures, the prevalence of BV and nonoptimal vaginal microbiome is increased for women of African descent, suggesting a possible role for host genetics. We conducted a genome-wide association study of important vaginal microbiome traits in Kenyan women. We identified novel genetic loci and biological pathways related to mucosal immunity, cell signaling, and infection that were associated with vaginal microbiome traits; we replicated previously reported loci associated with mucosal immune response. These results provide insight into potential host genetic influences on vaginal microbiome composition and can guide larger longitudinal studies, with genetic and functional comparison across microbiome sites within individuals and across populations.

Genital Micro-Organisms in Pregnancy

The microbiome of the female genital tract may undergo changes in pregnancy due to metabolic, endocrinological, and immunological alterations. These dysbiotic states may cause infections which may ascend upwards to the feto-placental unit or may be seeded hematogenously. These low grade and often low virulent infectious states lead to chronic inflammatory states and maybe associated with adverse maternal and neonatal outcome. Organisms have been isolated from amniotic fluid and placentae from women delivering pre-term; however the possibility of contamination cannot be conclusively ruled out. Common vaginal dysbiotic states often cause symptoms that are overlooked and often untreated. Vulvovaginal Candidiasis (VVC), Bacterial Vaginosis (BV), and Trichomonas Vaginitis (TV) are the commonly occurring dysbiotic states leading to vaginal infective states in pregnancy. With the advent of novel technologies like Next Generation sequencing (NGS), it will soon be possible to comprehensively map the vaginal microbiome and assess the interplay of each microbial state with their effects in pregnancy. This may open new avenues for antibiotic recommendations, probiotics and potential alternate therapies for dysbiotic states leading to pregnancy complications.

Oligosaccharides and Complex Carbohydrates: A New Paradigm for Cranberry Bioactivity

Cranberry is a well-known functional food, but the compounds directly responsible for many of its reported health benefits remain unidentified. Complex carbohydrates, specifically xyloglucan and pectic oligosaccharides, are the newest recognized class of biologically active compounds identified in cranberry materials. Cranberry oligosaccharides have shown similar biological properties as other dietary oligosaccharides, including effects on bacterial adhesion, biofilm formation, and microbial growth. Immunomodulatory and anti-inflammatory activity has also been observed. Oligosaccharides may therefore be significant contributors to many of the health benefits associated with cranberry products. Soluble oligosaccharides are present at relatively high concentrations (~20% w/w or greater) in many cranberry materials, and yet their possible contributions to biological activity have remained unrecognized. This is partly due to the inherent difficulty of detecting these compounds without intentionally seeking them. Inconsistencies in product descriptions and terminology have led to additional confusion regarding cranberry product composition and the possible presence of oligosaccharides. This review will present our current understanding of cranberry oligosaccharides and will discuss their occurrence, structures, ADME, biological properties, and possible prebiotic effects for both gut and urinary tract microbiota. Our hope is that future investigators will consider these compounds as possible significant contributors to the observed biological effects of cranberry.

Defining the relationship between vaginal and urinary microbiomes

BACKGROUND

Although the vaginal and urinary microbiomes have been increasingly well-characterized in health and disease, few have described the relationship between these neighboring environments. Elucidating this relationship has implications for understanding how manipulation of the vaginal microbiome may affect the urinary microbiome and treatment of common urinary conditions.

OBJECTIVE

To describe the relationship between urinary and vaginal microbiomes using 16S rRNA gene sequencing. We hypothesized that the composition of the urinary and vaginal microbiomes would be significantly associated, with similarities in predominant taxa.

STUDY DESIGN

This multicenter study collected vaginal swabs and catheterized urine samples from 186 women with mixed urinary incontinence enrolled in a parent study and 84 similarly aged controls. Investigators decided a priori that if vaginal and/or urinary microbiomes differed between continent and incontinent women, the groups would be analyzed separately; if similar, samples from continent and incontinent women would be pooled and analyzed together. A central laboratory sequenced variable regions 1-3 (v1-3) and characterized bacteria to the genus level. Operational taxonomic unit abundance was described for paired vaginal and urine samples. Pearson's correlation characterized the relationship between individual operational taxonomic units of paired samples. Canonical correlation analysis evaluated the association between clinical variables (including mixed urinary incontinence and control status) and vaginal and urinary operational taxonomic units, using the Canonical correlation analysis function in the Vegan package (R version 3.5). Linear discriminant analysis effect size was used to find taxa that discriminated between vaginal and urinary samples.

RESULTS

Urinary and vaginal samples were collected from 212 women (mean age 53±11 years) and results from 197 paired samples were available for analysis. As operational taxonomic units in mixed urinary incontinence and control samples were related in canonical correlation analysis and since taxa did not discriminate between mixed urinary incontinence or controls in either vagina or urine, mixed urinary incontinence and control samples were pooled for further analysis. Canonical correlation analysis of vaginal and urinary samples indicated that that 60 of the 100 most abundant operational taxonomic units in the samples largely overlapped. Lactobacillus was the most abundant genus in both urine and vagina (contributing on average 53% to an individual's urine sample and 64% to an individual's vaginal sample) (Pearson correlation r=0.53). Although less abundant than Lactobacillus, other bacteria with high Pearson correlation coefficients also commonly found in vagina and urine included: Gardnerella (r=0.70), Prevotella (r=0.64), and Ureaplasma (r=0.50). Linear discriminant analysis effect size analysis identified Tepidimonas and Flavobacterium as bacteria that distinguished the urinary environment for both mixed urinary incontinence and controls as these bacteria were absent in the vagina (Tepidimonas effect size 2.38, P<.001, Flavobacterium effect size 2.15, P<.001). Although Lactobacillus was the most abundant bacteria in both urine and vagina, it was more abundant in the vagina (linear discriminant analysis effect size effect size 2.72, P<.001).

CONCLUSION

Significant associations between vaginal and urinary microbiomes were demonstrated, with Lactobacillus being predominant in both urine and vagina. Abundance of other bacteria also correlated highly between the vagina and urine. This inter-relatedness has implications for studying manipulation of the urogenital microbiome in treating conditions such as urgency urinary incontinence and urinary tract infections.

Mechanistic insights into the action of probiotics against bacterial vaginosis and its mediated preterm birth: An overview

The human body is a reservoir of numerous micro-creatures; whose role is substantial and indispensable in the overall development of human beings. The advances in omic approaches have offered powerful means to decipher the core microbiome and metabolome diversities in a specific organ system. The establishment of lactobacilli in the female reproductive tract is thought to be a paramount prerequisite that maintains homeostatic conditions for a sustainable and healthy pregnancy. Nevertheless, a plethora of such Lactobacillus strains of vaginal source revealed probiotic phenotypes. The plummeting in the occurrence of lactobacilli in the vaginal ecosystem is associated with several adverse pregnancy outcomes (APOs). One such pathological condition is "Bacterial Vaginosis" (BV), a pathogen dominated gynecological threat. In this scenario, the ascending traffic of notorious Gram-negative/variable BV pathogens to the uterus is one of the proposed pathways that give rise to inflammation-related APOs like preterm birth. Since antibiotic resistance is aggravating among urogenital pathogens, the probiotics intervention remains one of the alternative biotherapeutic strategies to overcome BV and its associated APOs. Perhaps, the increased inclination towards the safer and natural biotherapeutic strategies rather than pharmaceutical drugs for maintaining gestational and reproductive health resulted in the use of probiotics in pregnancy diets. In this context, the current review is an attempt to highlight the microbiome and metabolites signatures of BV and non-BV vaginal ecosystem, inflammation or infection-related preterm birth, host-microbial interactions, role and effectiveness of probiotics to fight against aforesaid diseased conditions.

Re-assessing microbiomes in the low-biomass reproductive niche

The female reproductive tract represents a continuum between the vagina and the upper genital tract. New evidence from cultivation-independent studies suggests that the female upper genital tract is not sterile; however, the significance of this for reproductive health and disease remains to be elucidated fully. Further, diagnosis and treatment of infectious reproductive tract pathologies using cultivation-independent technologies represents a largely unchartered area of modern medical science. The challenge now is to design well-controlled experiments to account for the ease of contamination known to confound molecular-based studies of low-biomass niches, including the uterus and placenta. This will support robust assessment of the potential function of microorganisms, microbial metabolites, and cell-free bacterial DNA on reproductive function in health and disease. TWEETABLE ABSTRACT: Molecular microbial studies of low-biomass niches require stringent experimental controls to reveal causal relations in reproductive health and disease.