Biogenic Amines Increase the Odds of Bacterial Vaginosis and Affect the Growth of and Lactic Acid Production by Vaginal Lactobacillus spp

Bioinspired gelated cell sheet-supported lactobacillus biofilm for aerobic vaginitis diagnosis and treatment

Aerobic vaginitis (AV) is a long-standing inflammatory disease that affects female patients. The use of antibiotics is a common means for AV treatment, but it will indiscriminately kill both pathogenic bacteria and beneficial strains, which easily causes vaginal dysbacteriosis and infection recurrence. Herein, we describe a bioinspired strategy for fabricating gelated cell sheet-supported lactobacillus biofilms (GCS-LBs) for AV treatment. Compared with common planktonic probiotic formulations, probiotic biofilms forming on a robust GCS exhibit enhanced stress tolerance and better colonization capacity in the mouse vagina. Moreover, DNA nanodevices are decorated on the GCS and dynamically report the microenvironment change of biofilms for timely evaluating bacterium activity, both in vitro and in vivo. Consequently, GCS-LBs are used for treating AV in an Escherichia coli-infected mouse model, which shows enhanced therapeutic efficacy compared with conventional antibiotic or lactobacillus monotherapy. Overall, the GCS-LB shows promise as a potent multifunctional tool to combat bacterial infection.

Effect of host breeds on gut microbiome and fecal metabolome in commercial pigs

BACKGROUND

Gut microbial composition and its metabolites are crucial for livestock production performance. Metabolite profiles from autopsied biospecimens provide vital information on the basic mechanisms that affect the overall health and production traits in livestock animals. However, the role of the host breed in the gut microbiome and fecal metabolome of commercial pigs remains unclear. In this work, differences in microbiota composition among three commercial pig breeds Duroc, Yorkshire, and Landrace were measured by 16S rRNA gene sequencing. Fecal metabolite compositions of the three pig breeds were detected using untargeted metabolomics.

RESULTS

There were significant differences in the gut microbiomes of the three species, indicating that host breed affects the diversity and structure of gut microbiota. Several breed-associated microorganisms were identified at different taxonomic levels. Notely, most microbial taxa were annotated as Lactobacillacea, Muribaculaceae, and Oscillospiraceae. Several bacteria, including Lactobacillus, Subdoligranulum, Faecalibacterium, Oscillospira, Oscillospiraceae_UCG-002, and Christensenellaceae_R-7_group, could be considered as biomarkers for improving the backfat thickness (BF) for commercial pigs. Additionally, KEGG analysis of gut microbiota further revealed that arginine biosynthesis, pyruvate metabolism, and fatty acid biosynthesis varied greatly among pig breeds. Multiple gut bacterial metabolites (e.g., spermidine, estradiol, and palmitic acid) were identified as breed-associated. Mediation analysis ultimately revealed the cross-talk among gut microbiota, metabolites, and BF thickness, proclaiming that the microbial and metabolic biomarkers identified in this study could be used as biomarkers for improving BF phenotype.

CONCLUSIONS

This work provides vital insights into breed effects on gut microbiota and metabolite compositions of commercial pigs and uncovers potential biomarkers that are significant for pig breed improvement.

Retrospective Investigator-Initiated Trial on Tocopherol Acetate Vaginal Administration in Pre-and Postmenopausal Women

BACKGROUND

Menopause, a natural phase in a woman's life, often adversely affects physical, mental, sexual, and emotional well-being due to low estrogen levels. This study examines the impact of vaginal ovules with tocopherol acetate (Filme Gyno-V® ovules, manufactured by Panin Srl and distributed by Hulka Srl, Italy), 500 mg per ovule, on vaginal health in pre- and menopausal women.

METHODS

Fifty women aged 50-70 were divided into menopausal (28) and premenopausal (22) cohorts and treated with the ovules for two weeks, with assessments before and after treatment.

RESULTS

The findings showed that distressing symptoms of vaginal atrophy, such as dryness, itching, and pain during intercourse, were resolved post-treatment. A molecular analysis revealed a reduction in Escherichia coli in both cohorts and an increase in three species of Lactobacillus in premenopausal patients.

CONCLUSIONS

This study concludes that Filme Gyno-V ovules may benefit vaginal health by alleviating atrophy symptoms and promoting healthy vaginal microbiota.

Cervicovaginal microbiome, high-risk HPV infection and cervical cancer: Mechanisms and therapeutic potential

The microbiota in the female genital tract is an intricate assembly of diverse aerobic, anaerobic, and microaerophilic microorganisms, which share the space within the reproductive tract and engage in complex interactions. Microbiome dysbiosis may disrupt the symbiotic relationship between the host and microorganisms and play a pivotal role in the pathogenesis of various diseases, including its involvement in the establishment of human papillomavirus (HPV)-associated cervical cancer (CC). Interventions to restore microbiota homeostasis (e.g., probiotics) and bacterial-vector HPV therapeutic vaccines have been reported to be potentially effective in clearing HPV infection and ameliorating cytological abnormalities. In this review, we place emphasis on elucidating the alterations within the cervical-vaginal microbiota as well as the intratumoral microbiota in the context of high-risk HPV (HR-HPV) infection and its subsequent progression to cervical intraepithelial neoplasia/CC. Furthermore, we explore the mechanisms by which these microbial communities exert potential pathogenic or protective effects, including modulating genital inflammation and immune responses, affecting HR-HPV oncogene expression and oncoprotein production, regulating oxidative stress and deoxyribonucleic acid (DNA) damage, and inducing metabolic rewiring. Lastly, we summarize the latest evidence in human trials regarding the efficacy of probiotics, prebiotics and probiotic-vector HPV therapeutic vaccines. This review aims to foster a deeper understanding of the role of the microbiota in HR-HPV infection-related cervix cancer development, and further provide a theoretical basis for the development of preventive and therapeutic strategies based on microbial modulation.

Vaginal and endometrial microbiome dysbiosis associated with adverse embryo transfer outcomes

BACKGROUND

Assisted reproductive technology (ART) is the most effective method to treat infertility and the pathogenesis of implantation failure after in vitro fertilization-embryo transfer (IVF-ET) is a challenging filed in infertility. Microbes in the female reproductive tract are considered to be associated with gynecological and obstetric diseases. However, its effects on embryo implantation failure are unsured.

PURPOSE

This study aimed to investigate reproductive tract dysbiosis, identify different bacteria in reproductive tract as potential biomarkers of embryo implantation failure and demonstrate the pathogenesis through metabolites analysis.

METHODS

We compared the data from 16S rRNA gene and metagenome in reproductive tracts through QIIME2 and HUMAnN2 by the times of embryo implantation failure on 239 infertile patients and 17 healthy women.

RESULTS

Our study revealed a strong positive correlation between Lactobacillus abundance and embryo implantation success (IS) after IVF-ET. The microbial community composition and structure in reproductive tract showed substantially difference between the embryo implantation failure (IF) and healthy control. Moreover, we established a diagnostic model through receiver operating characteristic (ROC) with 0.913 area under curve (AUC) in IS and multiple implantation failures (MIF), verified its effectiveness with an AUC = 0.784 demonstrating microbial community alterations could efficiently discriminate MIF patients. Metagenome functional analyses of vaginal samples from another independent infertile patients after IVF-ET revealed the L-lysine synthesis pathway enriched in IF patients, along with ascended vaginal pH and decreased Lactobacillus abundance.

CONCLUSIONS

This study clarifies several independent relationships of bacteria in vagina and endometrial fluid on embryo implantation failure and undoubtedly broadens the understanding about female reproductive health.

Effects of vaginal microbiota on human papillomavirus infection and its related diseases

With the knowledge of female reproductive tract microbiota gradually increasing, the connection between vaginal microbiota (VMB) and its related diseases is increasingly highlighted. Manifestation of VMB keeps changing with various dominated bacteria, which can affect the immune response of mucosal barrier and the entrance of pathogens. Human papillomavirus (HPV), as an oncogenic virus, is closely related to viral-associated cancer, such as cervical cancer. According to HPV infection status, VMB can transform into different types, and result in accelerating or restraining the progression of diseases, which have exposed the inner link between VMB and HPV. Therefore, probiotics therapy promises to be a new complementary therapy to rebuild a healthy VMB for patients, but there's still a long way to go before its ready for the clinic. This review focuses on composition, immune response, and application of VMB in HPV and its associated diseases and aims to provide the new ideas and directions for the research on VMB.

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.

Medical-Grade Honey as a Potential New Therapy for Bacterial Vaginosis

The prevalence of bacterial vaginosis (BV) among women of reproductive age is 29%. BV arises from a vaginal imbalance marked by reduced levels of lactic acid-producing lactobacilli and an overgrowth of pathogenic anaerobes. The multifactorial nature of BV's pathogenesis complicates its treatment. Current antibiotic therapy exhibits a recurrence rate of about 60% within a year. Recurrence can be caused by antibiotic treatment failure (e.g., due to antimicrobial resistance), the persistence of residual infections (e.g., due to biofilm formation), and re-infection. Because of the high recurrence rates, alternative therapies are required. Medical-grade honey (MGH), known for its antimicrobial and wound healing properties in wound care, emerges as a potential novel therapy for BV. MGH exerts broad-spectrum antimicrobial activity, employing multiple mechanisms to eliminate the risk of resistance. For example, the low pH of MGH and the production of hydrogen peroxide benefit the microbiota and helps restore the natural vaginal balance. This is supported by in vitro studies demonstrating that MGH has an antibacterial effect on several pathogenic bacteria involved in the pathophysiology of BV, while lactobacilli and the vaginal microenvironment can be positively affected. In contrast to antibiotics, MGH exerts anti-biofilm activity, affects the microbiome as pre- and probiotic, and modulates the vaginal microenvironment through its anti-inflammatory, anti-oxidative, physicochemical, and immunomodulatory properties. More clinical research is required to confirm the positive effect of MGH on BV and to investigate the long-term cure rate.

A manifold-based framework for studying the dynamics of the vaginal microbiome

The vaginal microbiome plays a crucial role in our health. The composition of this community can be classified into five community state types (CSTs), four of which are primarily consisted of Lactobacillus species and considered healthy, while the fifth features non-Lactobacillus populations and signifies a disease state termed Bacterial vaginosis (BV), which is associated with various symptoms and increased susceptibility to diseases. Importantly, however, the exact mechanisms and dynamics underlying BV development are not yet fully understood, including specifically possible routes from a healthy to a BV state. To address this gap, this study set out to characterize the progression from healthy- to BV-associated compositions by analyzing 8026 vaginal samples and using a manifold-detection framework. This approach, inspired by single-cell analysis, aims to identify low-dimensional trajectories in the high-dimensional composition space. It further orders samples along these trajectories and assigns a score (pseudo-time) to each analyzed or new sample based on its proximity to the BV state. Our results reveal distinct routes of progression between healthy and BV states for each CST, with pseudo-time scores correlating with community diversity and quantifying the health state of each sample. Several BV indicators can also be successfully predicted based on pseudo-time scores, and key taxa involved in BV development can be identified using this approach. Taken together, these findings demonstrate how manifold detection can be used to successfully characterize the progression from healthy Lactobacillus-dominant populations to BV and to accurately quantify the health condition of new samples along the route of BV development.

Vaginal microecology and its role in human papillomavirus infection and human papillomavirus associated cervical lesions

The vaginal microecology comprises the vaginal microbiome, immune microenvironment, vaginal anatomy, and the cervicovaginal fluid, which is rich in metabolites, enzymes, and cytokines. Investigating its role in the female reproductive system holds paramount significance. The advent of next-generation sequencing enabled a more profound investigation into the structure of the vaginal microbial community in relation to the female reproductive system. Human papillomavirus infection is prevalent among women of reproductive age, and persistent oncogenic HPV infection is widely recognized as a factor associated with cervical cancer. Extensive previous research has demonstrated that dysbiosis of vaginal microbiota characterized by a reduction in Lactobacillus species, heightens susceptivity to HPV infection, consequently contributing to persistent HPV infection and the progression of cervical lesion. Likewise, HPV infection can exacerbate dysbiosis. This review aims to provide a comprehensive summary of current literatures and to elucidate potential mechanisms underlying the interaction between vaginal microecology and HPV infection, with the intention of offering valuable insights for future clinical interventions.

Investigating the impact of condomless vaginal intercourse and lubricant use on the vaginal metabolome: a pre-post observational study

OBJECTIVE

The vaginal metabolome is a significant factor in the vaginal microenvironment, and data are emerging on its independent role in urogenital health. Condomless vaginal intercourse and personal lubricant use are common practices that may affect the vaginal metabolome. The aim of the present study is to describe the associations between condomless intercourse and lubricant use on the vaginal metabolome.

METHODS

This study used archived mid-vaginal swabs from a 10-week observational cohort of reproductive age women who self-collected samples and recorded behavioural diaries daily. Cases and controls were defined as participants who self-reported condomless vaginal intercourse with or without lubricant use, respectively. Samples were drawn prior to and following condomless vaginal intercourse. Twenty-two case participants were race/ethnicity matched to 22 control participants. Mid-vaginal swabs were subjected to 16S rRNA gene amplicon sequencing and untargeted ultrahigh performance liquid chromatography tandem mass spectroscopy metabolomics. Bayesian mixed-effects regression (unadjusted and adjusted for the vaginal microbiota) was used to evaluate differences in metabolite concentration associated with vaginal intercourse and lubricant use.

RESULTS

Both condomless penile-vaginal intercourse and lubricant use were independently associated with higher (up to 8.3-fold) concentrations of metabolites indicative of epithelial damage (eg, sarcosine) and many host-produced antioxidants. Lubricant use was significantly associated with increases in lipids related to cellular damage, host-produced sphingolipids (antimicrobials), antioxidants and salicylate, a cooling agent common to lubricants, in a study design which controls for the independent effect of intercourse. Metabolites involved in oxidative stress and salicylate were strongly correlated with several molecular bacterial vaginosis-associated bacteria.

CONCLUSIONS

This study provides important foundational data on how condomless vaginal-penile intercourse and lubricant use affect the vaginal metabolome and may affect the protective mechanisms in the vaginal microenvironment.

Human papillomavirus associated cervical lesion: pathogenesis and therapeutic interventions

Human papillomavirus (HPV) is the most prevalent sexually transmitted virus globally. Persistent high-risk HPV infection can result in cervical precancerous lesions and cervical cancer, with 70% of cervical cancer cases associated with high-risk types HPV16 and 18. HPV infection imposes a significant financial and psychological burden. Therefore, studying methods to eradicate HPV infection and halt the progression of precancerous lesions remains crucial. This review comprehensively explores the mechanisms underlying HPV-related cervical lesions, including the viral life cycle, immune factors, epithelial cell malignant transformation, and host and environmental contributing factors. Additionally, we provide a comprehensive overview of treatment methods for HPV-related cervical precancerous lesions and cervical cancer. Our focus is on immunotherapy, encompassing HPV therapeutic vaccines, immune checkpoint inhibitors, and advanced adoptive T cell therapy. Furthermore, we summarize the commonly employed drugs and other nonsurgical treatments currently utilized in clinical practice for managing HPV infection and associated cervical lesions. Gene editing technology is currently undergoing clinical research and, although not yet employed officially in clinical treatment of cervical lesions, numerous preclinical studies have substantiated its efficacy. Therefore, it holds promise as a precise treatment strategy for HPV-related cervical lesions.

Metabolic signature for a dysbiotic microbiome in the female genital tract: A systematic review and meta-analysis

BACKGROUND

The vaginal microbiome (VMB) is a critical determinant of reproductive health, where a microbial shift towards a dysbiotic environment has implications for susceptibility to, and clinical presentation of sexually transmitted infections (STIs). Metabolomic profiling of the vaginal microenvironment has led to the identification of metabolic responses to clinical conditions of dysbiosis. However, no studies have examined metabolic markers that are common across conditions and can serve as a signature for vaginal dysbiosis.

METHOD OF STUDY

We have conducted a comprehensive systematic review and meta-analysis to identify consistently deregulated metabolites along with their impact on host and microbial metabolism during dysbiosis. We employed two complementary approaches including a vote counting analysis for all eligible studies identified in the systematic review, in addition to a meta-analysis for a subset of studies with sufficient available data. Significantly deregulated metabolites were then selected for pathway enrichment analysis.

RESULTS

Our results revealed a total of 502 altered metabolites reported across 10 dysbiotic conditions from 16 studies. Following a rigorous, collective analysis, six metabolites which were consistently downregulated and could be generalized to all dysbiotic conditions were identified. In addition, five downregulated and one upregulated metabolite was identified from a bacterial vaginosis (BV) focused sub-analysis. These metabolites have the potential to serve as a metabolic signature for vaginal dysbiosis. Their role in eight altered metabolic pathways indicates a disruption of amino acid, carbohydrate, and energy metabolism during dysbiosis.

CONCLUSION

Based on this analysis, we propose a schematic model outlining the common metabolic perturbations associated with vaginal dysbiosis, which can be potential targets for therapeutics and prophylaxis.

Increased genital mucosal cytokines in Canadian women associate with higher antigen-presenting cells, inflammatory metabolites, epithelial barrier disruption, and the depletion of L. crispatus

BACKGROUND

Cervicovaginal inflammation has been linked to negative reproductive health outcomes including the acquisition of HIV, other sexually transmitted infections, and cervical carcinogenesis. While changes to the vaginal microbiome have been linked to genital inflammation, the molecular relationships between the functional components of the microbiome with cervical immunology in the reproductive tract are understudied, limiting our understanding of mucosal biology that may be important for reproductive health.

RESULTS

In this study, we used a multi'-omics approach to profile cervicovaginal samples collected from 43 Canadian women to characterize host, immune, functional microbiome, and metabolome features of cervicovaginal inflammation. We demonstrate that inflammation is associated with lower amounts of L. crispatus and higher levels of cervical antigen-presenting cells (APCs). Proteomic analysis showed an upregulation of pathways related to neutrophil degranulation, complement, and leukocyte migration, with lower levels of cornified envelope and cell-cell adherens junctions. Functional microbiome analysis showed reductions in carbohydrate metabolism and lactic acid, with increases in xanthine and other metabolites. Bayesian network analysis linked L. crispatus with glycolytic and nucleotide metabolism, succinate and xanthine, and epithelial proteins SCEL and IVL as major molecular features associated with pro-inflammatory cytokines and increased APCs.

CONCLUSIONS

This study identified key molecular and immunological relationships with cervicovaginal inflammation, including higher APCs, bacterial metabolism, and proteome alterations that underlie inflammation. As APCs are involved in HIV transmission, parturition, and cervical cancer progression, further studies are needed to explore the interactions between these cells, bacterial metabolism, mucosal immunity, and their relationship to reproductive health. Video Abstract.

Moving beyond DNA: towards functional analysis of the vaginal microbiome by non-sequencing-based methods

Over the last two decades, sequencing-based methods have revolutionised our understanding of niche-specific microbial complexity. In the lower female reproductive tract, these approaches have enabled identification of bacterial compositional structures associated with health and disease. Application of metagenomics and metatranscriptomics strategies have provided insight into the putative function of these communities but it is increasingly clear that direct measures of microbial and host cell function are required to understand the contribution of microbe-host interactions to pathophysiology. Here we explore and discuss current methods and approaches, many of which rely upon mass-spectrometry, being used to capture functional insight into the vaginal mucosal interface. In addition to improving mechanistic understanding, these methods offer innovative solutions for the development of diagnostic and therapeutic strategies designed to improve women's health.

Lactobacillus crispatus-loaded electrospun fibers yield viable and metabolically active bacteria that kill Gardnerella in vitro

Bacterial vaginosis (BV) is a common condition that affects one-third of women worldwide. BV is characterized by low levels of healthy lactobacilli and an overgrowth of common anaerobes such as Gardnerella. Antibiotics for BV are administered orally or vaginally; however, approximately half of those treated will experience recurrence within 6 months. Lactobacillus crispatus present at high levels has been associated with positive health outcomes. To address the high recurrence rates following BV treatment, beneficial bacteria have been considered as an alternative or adjunct modality. This study aimed to establish proof-of-concept for a new long-acting delivery vehicle for L. crispatus. Here, it is shown that polyethylene oxide (PEO) fibers loaded with L. crispatus can be electrospun with poly(lactic-co-glycolic acid) (PLGA) fibers (ratio 1:1), and that this construct later releases L. crispatus as metabolically viable bacteria capable of lactic acid production and anti-Gardnerella activity. Probiotic-containing fibers were serially cultured in MRS (deMan, Rogosa, Sharpe) broth with daily media replacement and found to yield viable L. crispatus for at least 7 days. Lactic acid levels and corresponding pH values generally corresponded with levels of L. crispatus cultured from the fibers and strongly support the conclusion that fibers yield viable L. crispatus that is metabolically active. Cultures of L. crispatus-loaded fibers limited the growth of Gardnerella in a dilution-dependent manner during in vitro assays in the presence of cultured vaginal epithelial cells, demonstrating bactericidal potential. Exposure of VK2/E6E7 cells to L. crispatus-loaded fibers resulted in minimal loss of viability relative to untreated cells. Altogether, these data provide proof-of-concept for electrospun fibers as a candidate delivery vehicle for application of vaginal probiotics in a long-acting form.

Fabrication and characterization of bioprints with Lactobacillus crispatus for vaginal application

Bacterial vaginosis (BV) is characterized by low levels of lactobacilli and overgrowth of potential pathogens in the female genital tract. Current antibiotic treatments often fail to treat BV in a sustained manner, and > 50% of women experience recurrence within 6 months post-treatment. Recently, lactobacilli have shown promise for acting as probiotics by offering health benefits in BV. However, as with other active agents, probiotics often require intensive administration schedules incurring difficult user adherence. Three-dimensional (3D)-bioprinting enables fabrication of well-defined architectures with tunable release of active agents, including live mammalian cells, offering the potential for long-acting probiotic delivery. One promising bioink, gelatin alginate has been previously shown to provide structural stability, host compatibility, viable probiotic incorporation, and cellular nutrient diffusion. This study formulates and characterizes 3D-bioprinted Lactobacillus crispatus-containing gelatin alginate scaffolds for gynecologic applications. Different weight to volume (w/v) ratios of gelatin alginate were bioprinted to determine formulations with highest printing resolution, and different crosslinking reagents were evaluated for effect on scaffold integrity via mass loss and swelling measurements. Post-print viability, sustained-release, and vaginal keratinocyte cytotoxicity assays were conducted. A 10:2 (w/v) gelatin alginate formulation was selected based on line continuity and resolution, while degradation and swelling experiments demonstrated greatest structural stability with dual genipin and calcium crosslinking, showing minimal mass loss and swelling over 28 days. 3D-bioprinted L. crispatus-containing scaffolds demonstrated sustained release and proliferation of live bacteria over 28 days, without impacting viability of vaginal epithelial cells. This study provides in vitro evidence for 3D-bioprinted scaffolds as a novel strategy to sustain probiotic delivery with the ultimate goal of restoring vaginal lactobacilli following microbiological disturbances.

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.

Bacterial Vaginosis Monitoring with Carbon Nanotube Field-Effect Transistors

The ability to rapidly and reliably screen for bacterial vaginosis (BV) during pregnancy is of great significance for maternal health and pregnancy outcomes. In this proof-of-concept study, we demonstrated the potential of carbon nanotube field-effect transistors (NTFET) in the rapid diagnostics of BV with the sensing of BV-related factors such as pH and biogenic amines. The fabricated sensors showed good linearity to pH changes with a linear correlation coefficient of 0.99. The pH sensing performance was stable after more than one month of sensor storage. In addition, the sensor was able to classify BV-related biogenic amine-negative/positive samples with machine learning, utilizing different test strategies and algorithms, including linear discriminant analysis (LDA), support vector machine (SVM), and principal component analysis (PCA). The biogenic amine sample status could be well classified using a soft-margin SVM model with a validation accuracy of 87.5%. The accuracy could be further improved using a gold gate electrode for measurement, with accuracy higher than 90% in both LDA and SVM models. We also explored the sensing mechanisms and found that the change in NTFET off current was crucial for classification. The fabricated sensors successfully detect BV-related factors, demonstrating the competitive advantage of NTFET for point-of-care diagnostics of BV.

Immunometabolic Analysis of Mobiluncus mulieris and Eggerthella sp. Reveals Novel Insights Into Their Pathogenic Contributions to the Hallmarks of Bacterial Vaginosis

The cervicovaginal microbiome plays an important role in protecting women from dysbiosis and infection caused by pathogenic microorganisms. In healthy reproductive-age women the cervicovaginal microbiome is predominantly colonized by protective Lactobacillus spp. The loss of these protective bacteria leads to colonization of the cervicovaginal microenvironment by pathogenic microorganisms resulting in dysbiosis and bacterial vaginosis (BV). Mobiluncus mulieris and Eggerthella sp. are two of the many anaerobes that can contribute to BV, a condition associated with multiple adverse obstetric and gynecological outcomes. M. mulieris has been linked to high Nugent scores (relating to BV morphotypes) and preterm birth (PTB), whilst some bacterial members of the Eggerthellaceae family are highly prevalent in BV, and identified in ~85-95% of cases. The functional impact of M. mulieris and Eggerthella sp. in BV is still poorly understood. To determine the individual immunometabolic contributions of Eggerthella sp. and M. mulieris within the cervicovaginal microenvironment, we utilized our well-characterized human three-dimensional (3-D) cervical epithelial cell model in combination with multiplex immunoassays and global untargeted metabolomics approaches to identify key immune mediators and metabolites related to M. mulieris and Eggerthella sp. infections. We found that infection with M. mulieris significantly elevated multiple proinflammatory markers (IL-6, IL-8, TNF-α and MCP-1) and altered metabolites related to energy metabolism (nicotinamide and succinate) and oxidative stress (cysteinylglycine, cysteinylglycine disulfide and 2-hydroxygluatrate). Eggerthella sp. infection significantly elevated multiple sphingolipids and glycerolipids related to epithelial barrier function, and biogenic amines (putrescine and cadaverine) associated with elevated vaginal pH, vaginal amine odor and vaginal discharge. Our study elucidated that M. mulieris elevated multiple proinflammatory markers relating to PTB and STI acquisition, as well as altered energy metabolism and oxidative stress, whilst Eggerthella sp. upregulated multiple biogenic amines associated with the clinical diagnostic criteria of BV. Future studies are needed to evaluate how these bacteria interact with other BV-associated bacteria within the cervicovaginal microenvironment.

Bacterial vaginosis and health-associated bacteria modulate the immunometabolic landscape in 3D model of human cervix

Bacterial vaginosis (BV) is an enigmatic polymicrobial condition characterized by a depletion of health-associated Lactobacillus and an overgrowth of anaerobes. Importantly, BV is linked to adverse gynecologic and obstetric outcomes: an increased risk of sexually transmitted infections, preterm birth, and cancer. We hypothesized that members of the cervicovaginal microbiota distinctly contribute to immunometabolic changes in the human cervix, leading to these sequelae. Our 3D epithelial cell model that recapitulates the human cervical epithelium was infected with clinical isolates of cervicovaginal bacteria, alone or as a polymicrobial community. We used Lactobacillus crispatus as a representative health-associated commensal and four common BV-associated species: Gardnerella vaginalis, Prevotella bivia, Atopobium vaginae, and Sneathia amnii. The immunometabolic profiles of these microenvironments were analyzed using multiplex immunoassays and untargeted global metabolomics. A. vaginae and S. amnii exhibited the highest proinflammatory potential through induction of cytokines, iNOS, and oxidative stress-associated compounds. G. vaginalis, P. bivia, and S. amnii distinctly altered physicochemical barrier-related proteins and metabolites (mucins, sialic acid, polyamines), whereas L. crispatus produced an antimicrobial compound, phenyllactic acid. Alterations to the immunometabolic landscape correlate with symptoms and hallmarks of BV and connected BV with adverse women’s health outcomes. Overall, this study demonstrated that 3D cervical epithelial cell colonized with cervicovaginal microbiota faithfully reproduce the immunometabolic microenvironment previously observed in clinical studies and can successfully be used as a robust tool to evaluate host responses to commensal and pathogenic bacteria in the female reproductive tract.

Vaginal microbiota of American Indian women and associations with measures of psychosocial stress

Molecular-bacterial vaginosis (BV) is characterized by low levels of vaginal Lactobacillus species and is associated with higher risk of sexually transmitted infections (STI). Perceived psychosocial stress is associated with increased severity and persistence of infections, including STIs. American Indians have the highest rates of stress and high rates of STIs. The prevalence of molecular-BV among American Indian women is unknown. We sought to evaluate measures of psychosocial stress, such as historic loss (a multigenerational factor involving slavery, forced removal from one's land, legally ratified race-based segregation, and contemporary discrimination) and their association with the vaginal microbiota and specific metabolites associated with BV, in 70 Northwestern Plains American Indian women. Demographics, perceived psychosocial stressors, sexual practices, and known BV risk factors were assessed using a modified version of the American Indian Service Utilization, Psychiatric Epidemiology, Risk and Protective Factors Project survey. Self-collected mid-vaginal swabs were profiled for bacterial composition by 16S rRNA gene amplicon sequencing and metabolites quantified by targeted liquid-chromatography mass spectrometry. Sixty-six percent of the participants were classified as having molecular-BV, with the rest being either dominated by L. crispatus (10%) or L. iners (24%). High levels of lifetime trauma were associated with higher odds of having molecular-BV (adjusted Odds Ratio (aOR): 2.5, 95% Credible Interval (CrI): 1.1-5.3). Measures of psychosocial stress, including historic loss and historic loss associated symptoms, were significantly associated with lifestyle and behavioral practices. Higher scores of lifetime trauma were associated with increased concentrations of spermine (aFC: 3.3, 95% CrI: 1.2-9.2). Historic loss associated symptoms and biogenic amines were the major correlates of molecular-BV. Historical loss associated symptoms and lifetime trauma are potentially important underlying factors associated with BV.

A non-optimal cervicovaginal microbiota in pregnancy is associated with a distinct metabolomic signature among non-Hispanic Black individuals

Biomechanical and molecular processes of premature cervical remodeling preceding spontaneous preterm birth (sPTB) likely result from interactions between the cervicovaginal microbiota and host immune responses. A non-optimal cervicovaginal microbiota confers increased risk of sPTB. The cervicovaginal space is metabolically active in pregancy; microbiota can produce, modify, and degrade metabolites within this ecosystem. We establish that cervicovaginal metabolomic output clusters by microbial community in pregnancy among Black individuals, revealing increased metabolism within the amino acid and dipeptide pathways as hallmarks of a non-optimal microbiota. Few differences were detected in metabolomic profiles when stratified by birth outcome. The study raises the possibility that metabolites could distinguish women with greater risk of sPTB among those with similar cervicovaginal microbiota, and that metabolites within the amino acid and carbohydrate pathways may play a role in this distinction.

The Two-Way Interaction between the Molecules That Cause Vaginal Malodour and Lactobacilli: An Opportunity for Probiotics

Vaginal malodour is a sign of dysbiosis. The biogenic amines (BAs) cadaverine, putrescine and tyramine are known to be causative compounds. Recent reports suggest these compounds produced by pathogens might have a role beyond causing malodour; namely inhibiting the growth of lactobacilli bacteria that are crucial in the maintenance of vaginal homeostasis. The aim of this study was to identify whether certain lactobacilli strains could reduce BAs and to evaluate how Lactobacillus species were affected by these compounds. Using LC–MS and HPLC-UV, five Lactobacillus crispatus strains were identified as being capable of significantly reducing BAs from the media under in vitro conditions. Through 16S rRNA gene sequencing of vaginal swabs exposed to Bas, cadaverine was found to reduce the relative abundance of lactobacilli. When L. crispatus was exposed to media supplemented with BAs with an HCl adjusted lower pH, its growth was enhanced, demonstrating the relevance of the maintenance of an acidic vaginal environment. If strains are to be developed for probiotic application to alleviate bacterial vaginosis and other conditions affecting large numbers of women worldwide, their ability to adapt to Bas and regulate pH should be part of the experimentation.

Interstrain Variability of Human Vaginal Lactobacillus crispatus for Metabolism of Biogenic Amines and Antimicrobial Activity against Urogenital Pathogens

Lactobacillus crispatus is the dominant species in the vagina of many women. With the potential for strains of this species to be used as a probiotic to help prevent and treat dysbiosis, we investigated isolates from vaginal swabs with Lactobacillus-dominated and a dysbiotic microbiota. A comparative genome analysis led to the identification of metabolic pathways for synthesis and degradation of three major biogenic amines in most strains. However, targeted metabolomic analysis of the production and degradation of biogenic amines showed that certain strains have either the ability to produce or to degrade these compounds. Notably, six strains produced cadaverine, one produced putrescine, and two produced tyramine. These biogenic amines are known to raise vaginal pH, cause malodour, and make the environment more favourable to vaginal pathogens. In vitro experiments confirmed that strains isolated from women with a dysbiotic vaginal microbiota have higher antimicrobial effects against the common urogenital pathogens Escherichia coli and Enterococcus faecium. The results indicate that not all L. crispatus vaginal strains appear suitable for probiotic application and the basis for selection should not be only the overall composition of the vaginal microbiota of the host from which they came, but specific biochemical and genetic traits.