Vulvovaginal candidiasis (VVC) is one of the most common infections caused by Candida albicans. VVC is characterized by an inadequate hyperinflammatory response and clinical symptoms associated with Candida colonization of the vaginal mucosa. Compared to other host niches in which C. albicans can cause infection, the vaginal environment is extremely rich in lactic acid that is produced by the vaginal microbiota. We examined how lactic acid abundance in the vaginal niche impacts the interaction between C. albicans and the human immune system using an in vitro culture in vaginal simulative medium (VSM). The presence of lactic acid in VSM (VSM+LA) increased C. albicans proliferation, hyphal length, and its ability to cause damage during subsequent infection of vaginal epithelial cells. The cell wall of C. albicans cells grown in VSM+LA displayed a robust mannan fibrillar structure, β-glucan exposure, and low chitin content. These cell wall changes were associated with altered immune responses and an increased ability of the fungus to induce trained immunity. Neutrophils were compromised in clearing C. albicans grown in VSM+LA conditions, despite mounting stronger oxidative responses. Collectively, we found that fungal adaptation to lactic acid in a vaginal simulative context increases its immunogenicity favouring a pro-inflammatory state. This potentially contributes to the immune response dysregulation and neutrophil recruitment observed during recurrent VVC.

Urinary tract infection (UTI) treatment is a growing public health concern owing to increasing antimicrobial resistance. Phage therapy, an alternative or adjunctive treatment to antibiotics, has the potential to address this challenge. However, clinical use of phage therapy is hindered by knowledge gaps and inconsistent reporting. The objective was to review the current state of phage therapy for UTIs and highlight research priorities that can optimize phage clinical efficacy.

Current literature on UTI phage therapy was examined, focusing on the lack of standardized phage susceptibility testing, phage characterization, and microbiological assessments during and after treatment.

Critical areas requiring further investigation include appropriate phage dosing, optimal routes of administration, and the dynamics of phage-host and phage-patient interactions. The influence of the urinary microbiome, including endogenous phages, on treatment outcomes also needs to be better understood. Suggested data collection and reporting standards should be developed and implemented to improve clinical impact of studies examining phage therapy for UTI. Randomized clinical trials are needed to establish efficacy and determine the best practices for clinical use.

Phage therapy is a promising alternative to antibiotics for managing UTIs, especially in the face of rising antimicrobial resistance. To fully realize its potential, however, future research must focus on standardized protocols, dosing strategies, and the role of the urinary microbiome, with an emphasis on rigorously conducted clinical trials. These steps are essential for integrating phage therapy into mainstream UTI treatment regimens.

The vaginal microbiome, a relatively simple, low diversity ecosystem crucial for female health, is often dominated by Lactobacillus spp. Detailed strain-level data, facilitated by shotgun sequencing, can provide a greater understanding of the mechanisms of colonization and host-microbe interactions. We analysed 354 vaginal metagenomes from pregnant women in Ireland to investigate metagenomic community state types and strain-level variation, focusing on cell surface interfaces. Our analysis revealed multiple subspecies, with Lactobacillus crispatus and Lactobacillus iners being the most dominant. We found genes, including putative mucin-binding genes, distinct to L. crispatus subspecies. Using 337 metagenome-assembled genomes, we observed a higher number of strain-specific genes in L. crispatus related to cell wall biogenesis, carbohydrate and amino acid metabolism, many under positive selection. A cell surface glycan gene cluster was predominantly found in L. crispatus but absent in L. iners and Gardnerella vaginalis. These findings highlight strain-specific factors associated with colonisation and host-microbe interactions.

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide. They occur in the urinary system when a microorganism, commonly present on the perineal skin or rectum, reaches the bladder through the urethra, and adheres to the luminal surface of uroepithelial cells, forming biofilms. The treatment of UTIs includes antibiotics, but their indiscriminate use has favored the development of multidrug-resistant bacteria strains, which represent a serious challenge to today's microbiology. The pathogenesis of the infection and antibiotic resistance synergistically contribute to hindering the eradication of the disease while favoring the establishment of persistent infections. The repeated requirement for antibiotic treatment and the limited therapeutic options have further contributed to the increase in antibiotic resistance and the occurrence of potential relapses by therapeutic failure. To limit antimicrobial resistance and broaden the choice of non-antibiotic preventive approaches, this review reports studies focused on the bacteriostatic/bactericidal activity, inhibition of bacterial adhesion and quorum sensing, restoration of uroepithelial integrity and immune response of molecules, vitamins, and compounds obtained from plants. To date, different supplementations are recommended by the European Association of Urology for the management of UTIs as an alternative approach to antibiotic treatment, while a variety of bioactive compounds are under investigation, mostly at the level of in vitro and preclinical studies. Although the evidence is promising, they are far from being included in the clinical practice of UTIs.

Infertility affects couples at reproductive age, with in vitro fertilization (IVF) being the most effective treatment. Success rates of IVF are influenced by several factors, including a healthy female reproductive system microbiome, which can improve implantation rates and pregnancy outcomes. This study evaluated the impact of Ligilactobacillus salivarius PS11610 on IVF outcomes. This strain showed antimicrobial activity against pathogens related to dysbiosis, commonly observed in women undergoing assisted reproductive treatment.

The administration of L. salivarius PS11610 at a dose of 1 × 109 CFU every 12 h for at least one month before IVF procedures, particularly in the frozen embryo transfer (FET) group, appears to enhance the success rate of IVF. IVF procedures without embryo transfer showed no significant differences between the groups. However, there were statistically significant differences in the quality of embryos, specifically in category 2, which were higher in the group without L. salivarius PS11610 supplementation (p = 0.042). Similar results were seen in the IVF with embryo transfer group, where the quality of embryos in categories 2 and 3 was higher in the group without L. salivarius PS11610 (p = 0.019 and p = 0.05, respectively). IVF with FET showed notable improvements, where intake of L. salivarius PS11610 was associated with a significant increase in live birth infants (26.4% with L. salivarius PS11610 vs. 17.9% without, p = 0.034) and higher biochemical pregnancy rates (42.6% vs. 34%, p = 0.071).

Despite some differences in embryo quality, the overall positive impact on pregnancy and birth outcomes highlights L. salivarius PS11610 as a promising supplement in assisted reproductive treatments.

The vaginal microbiota has demonstrated associations with women's and newborns' health. Despite its comparatively simple composition relative to other human microbiota systems, the ecological processes that underpin the dynamics and stability of vaginal microbial communities remain mechanistically elusive. A crucial, yet so far underexplored, aspect of vaginal microbiota ecology is the role played by nutritional resources. Glycogen and its derivatives, produced by vaginal epithelia, are accessible to all bacterial constituents of the microbiota. Concurrently, free sialic acid and fucose offer supplementary nutritional resources for bacterial strains capable of cleaving them from glycans, which are structurally integral to mucus. Notably, bacteria adept at sialic acid exploitation are often correlated with adverse clinical outcomes and are frequently implicated in bacterial vaginosis (BV). In this study, we introduce a novel mathematical model tailored to human vaginal microbiota dynamics to explore the interactions between bacteria and their respective nutritional landscapes. Our resource-based model examines the impact of the relative availability of glycogen derivatives (accessible to all bacterial species) and sialic acid (exclusive to some BV-associated bacteria) on the composition of the vaginal microbiota. Our findings elucidate that the prevalence of BV-associated bacteria is intricately linked to their exclusive access to specific nutritional resources. This private access fortifies communities dominated by BV-associated bacteria, rendering them resilient to compositional transitions. We provide empirical support for our model's predictions from longitudinal microbiota composition and unpublished metabolomic data, collected from a North American cohort. The insights gleaned from this study shed light on potential pathways for BV prevention.

The vaginal microbiota has a notable impact on women's health at various stages of life, namely puberty, infection protection, sexual health, fertility, pregnancy, and menopausal changes. Yet, even though women frequently seek out treatment of vaginal symptoms, most non-anti-microbial products emphasise competitive interactions through acids (boric or lactic acid) or probiotics as a means to "rebalance" microbiota communities. However, despite recent advances in profiling the composition of vaginal microbiota communities, there remains a major gap in our mechanistic understanding of how to maintain or reinstate a resilient Lactobacillus -dominated microbiota that improves vaginal health and outcomes. This study explores the role of nutritional resources in the vaginal microbiota by introducing a mathematical model that analyses how access to specific nutrients like glycogen derivatives and sialic acid affects the balance of bacterial vaginosis (BV) and non-BV-associated bacteria. Results, supported by original cohort-derived microbiological and metabolomics data, show that exclusive access to these nutrients is linked to the dominance and resilience of BV-associated bacteria, providing new insights for BV prevention and treatment.

Assisted reproductive technology (ART) has been evolving since 1978, with the number of techniques performed increasing over the years. Despite continued advances, some couples continue to have difficulties getting pregnant, and it has recently been considered that the microbiome of the female genital tract (FGT) may influence embryo implantation and the establishment of pregnancy. This review aims to evaluate the role of probiotics on reproductive outcomes in infertile women on ART. A search throughout medical databases was performed, and six articles met the criteria. Five studies showed improvements in pregnancy rates, with only one demonstrating statistical significance. One article showed no improvement but reported a statistically significant reduction in the miscarriage rate in the probiotic group. Further research is needed to evaluate the true potential of probiotics, namely to assess whether they effectively modulate the FGT microbiome and if these changes are maintained over time.

Chronic endometritis (CE) is a prolonged, mild inflammation of the endometrial lining. This study investigated the impact of the impact of antibiotic treatment combined with vaginal Lactobacillus on pregnancy outcomes in infertile patients with CE during frozen embryo transfer (FET) cycles.

A retrospective analysis was performed on the clinical data of 7,385 patients who underwent FET. After applying the inclusion and exclusion criteria, 254 patients diagnosed with CE were eligible for inclusion. Of these, 119 patients received antibiotics alone, whereas 135 were treated with a combination of doxycycline and vaginal Lactobacillus. All patients underwent embryo transfer within 6 months following treatment. The general characteristics and pregnancy outcomes of the first FET cycle post-treatment were compared between the two groups.

There were no statistically significant differences between the two groups in terms of general characteristics, clinical pregnancy rate, early miscarriage rate, and ectopic pregnancy rate. Patients who received a combination of doxycycline and Lactobacillus showed a higher biochemical pregnancy rate compared to those who received doxycycline alone, though this difference was not statistically significant (70.37% vs. 64.71%, P=0.313). Furthermore, the incidence rate of premature rupture of membranes was lower in the doxycycline-Lactobacillus group than in the doxycycline group (50.00% vs 33.33%, P=0.037).

Although this study observed the potential benefits of the antibiotic and vaginal probiotic treatment regimen in increasing the biochemical pregnancy rate and reducing the incidence of premature rupture of membranes, the current findings are insufficient to recommend the combined use of antibiotics and vaginal Lactobacillus as an intervention to improve reproductive outcomes in infertile patients with CE.

This review provides a comprehensive overview of the current state of probiotic research, covering a wide range of topics, including strain identification, functional characterization, preclinical and clinical evaluations, mechanisms of action, therapeutic applications, manufacturing considerations, and future directions. The screening process for potential probiotics involves phenotypic and genomic analysis to identify strains with health-promoting properties while excluding those with any factor that could be harmful to the host. In vitro assays for evaluating probiotic traits such as acid tolerance, bile metabolism, adhesion properties, and antimicrobial effects are described. The review highlights promising findings from in vivo studies on probiotic mitigation of inflammatory bowel diseases, chemotherapy-induced mucositis, dysbiosis, obesity, diabetes, and bone health, primarily through immunomodulation and modulation of the local microbiota in human and animal models. Clinical studies demonstrating beneficial modulation of metabolic diseases and human central nervous system function are also presented. Manufacturing processes significantly impact the growth, viability, and properties of probiotics, and the composition of the product matrix and supplementation with prebiotics or other strains can modify their effects. The lack of regulatory oversight raises concerns about the quality, safety, and labeling accuracy of commercial probiotics, particularly for vulnerable populations. Advancements in multi-omics approaches, especially probiogenomics, will provide a deeper understanding of the mechanisms behind probiotic functionality, allowing for personalized and targeted probiotic therapies. However, it is crucial to simultaneously focus on improving manufacturing practices, implementing quality control standards, and establishing regulatory oversight to ensure the safety and efficacy of probiotic products in the face of increasing therapeutic applications.

The purpose of this study was to conduct a comparative analysis of the composition of the dominant groups of vaginal microorganisms in healthy pregnant women and pregnant women infected with HPV using a microbiological culture-based method. The MALDI TOF MS method and 16S rRNA gene fragment sequencing were used to identify microorganisms isolated from healthy pregnant women (n=32) and pregnant women infected with HPV (n=24). It was found that vaginal secretion samples from both groups contained bacteria of 4 phyla: Bacillota, Actinomycetota, Pseudomonadota, Bacteroidota, and Ascomycota fungi. The most common microbial community in healthy pregnant women being CST I (p=0.0007), and CST V in pregnant women infected with HPV (p=0.0001). At the genus level, a total of 25 taxa were found in all samples, with Lactobacillus being the dominant genus overall. Escherichia (p<0.0001) and Prevotella (p=0.0001) concentrations were higher in HPV infected patients. When calculating the Pearson correlation coefficient for the phyla, it was found that Bacillota correlated negatively with HPV genotypes 16 and 51 (p≤0.05), but positively with HPV genotype 59 (p≤0.05), just like Actinomycetota (p≤0.05). Bacteroidota correlated positively with HPV genotype 56 (0.001 Collapse

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.

Preterm birth affects approximately 15 million women worldwide, of which 30 % is due to preterm premature rupture of membranes (PPROM). The reasons for shortening the duration of pregnancy are seen in genetic, hormonal, immunological and socio-economic conditions. Recent years have provided a lot of evidence on the impact of the microbiota and whole microbiome on pregnant women, suggesting that the microorganisms inhabiting the vagina significantly affect the risk of preterm delivery. The aim of the study was to review studies evaluating the composition of the vaginal microflora and its role in the occurrence of preterm labor caused by PPROM, and to evaluate the potential beneficial effect of probiotics on preventing the development of preterm labor. Vaginal microbial dysbiosis is observed in PPROM, which, due to its association with a high risk of prematurity and infection, increases neonatal morbidity and mortality. Further research on biomarkers for screening, early prognosis and diagnosis of PPROM seems advisable. Probiotics as a potential intervention can prevent the development of pathological vaginal flora, reducing the risk of infection in women planning pregnancy and pregnant women.

Disorders of the vaginal microbiota can lead to many complications and affect fertility. This study evaluates the role of Lactobacillus in the vagina and its impact on the incidence of colonization by pathogenic microorganisms, analyzing the results of 1,039 women of reproductive age (18-49 years) who underwent a microbiological examination of the reproductive tract in 2020. Samples were examined by microscopy, culture, and NAAT. As the number of Lactobacillus increases, the chance of developing symptoms decreases. In fact, it has been shown that the higher the number of Lactobacillus spp. the less frequently Gardnerella vaginalis and Streptococcus group B are observed. As the concentration of Lactobacillus spp. increases by one category, the risk of G. vaginalis after adjustment to age and pH decreases by 80% (p < 0.001). Similarly, the correlation between Lactobacillus spp. and vaginal pH was shown. After adjustment to age, the odds of prevalence pH > 4.5 for people with Lactobacillus category higher 1 is 76% lower.

Protective immunity to opportunistic fungal infections consists of tightly regulated innate and adaptive immune responses that clear the infection. Immune responses to infections of the vaginal mucosa by Candida species are, however, an exception. In the case of vulvovaginal candidiasis (VVC), the inflammatory response is associated with symptomatic disease, rather than that it results in pathogen clearance. As such VVC can be considered an inflammatory disease, which is a significant public health problem due to its predominance as a female-specific fungal infection. Particularly, women with recurrent VVC (RVVC) suffer from a significant negative impact on their quality of life and mental health. Knowledge of the inflammatory pathogenesis of (R)VVC may guide more effective diagnostic and therapeutic options to improve the quality of life of women with (R)VVC. Here, we review the immunopathogenesis of (R)VVC describing several elements that induce an inflammatory arson, starting with the activation threshold established by vaginal epithelial cells that prevent unnecessary ignition of inflammatory responses, epithelial and inflammasome-dependent immune responses. These inflammatory responses will drive neutrophil recruitment and dysfunctional neutrophil-mediated inflammation. We also review the, sometimes controversial, findings on the involvement of adaptive and systemic responses. Finally, we provide future perspectives on the potential of some unexplored cytokine axes and discuss whether VVC needs to be subdivided into subgroups to improve diagnosis and treatment.

Lactobacillus crispatus is a frequent member of the female urogenital microbiota. Here, we present the draft genome assemblies of three L. crispatus strains: UMB4356, UMB5661, and UMB6244. All strains were isolated from voided urine samples from females with type 2 diabetes.

Probiotics offer a promising prophylactic approach against various pathogens and represent an alternative strategy to combat biofilm-related infections. In this study, we isolated vaginal commensal microbiota from 54 healthy Indian women to investigate their probiotic traits. We primarily explored the ability of cell-free supernatant (CFS) from Lactobacilli to prevent Uropathogenic Escherichia coli (UPEC) colonization and biofilm formation. Our findings revealed that CFS effectively reduced UPEC's swimming and swarming motility, decreased cell surface hydrophobicity, and hindered matrix production by downregulating specific genes (fimA, fimH, papG, and csgA). Subsequent GC-MS analysis identified Tryptamine, a monoamine compound, as the potent bioactive substance from Lactobacilli CFS, inhibiting UPEC biofilms with an MBIC of 4 µg/ml and an MBEC of 8 µg/ml. Tryptamine induced significant changes in E. coli colony biofilm morphology, transitioning from the Red, Dry, and Rough (RDAR) to the Smooth and White phenotype, indicating reduced extracellular matrix production. Biofilm time-kill assays demonstrated a four-log reduction in UPEC viability when treated with Tryptamine, highlighting its potent antibacterial properties, comparable to CFS treatment. Biofilm ROS assays indicated a significant elevation in ROS generation within UPEC biofilms, suggesting a potential antibacterial mechanism. Gene expression studies with Tryptamine-treated samples showed a reduction in expression of curli gene (csgA), consistent with CFS treatment. This study underscores the potential of Tryptamine from probiotic Lactobacilli CFS as a promising antibiofilm agent against UPEC biofilms.

To study how indigenous or probiotic-introduced lactobacilli affect the sensitivity (estimated as the proportion of surviving, apoptotic, and nonapoptotic deaths) of vaginal epithelial cells obtained from HPV-negative and HPV-positive patients to oxidative damage. The tendency to resist oxidative damage in vaginal epithelial cells of 147 HPV-positive and 59 HPV-negative patients with physiological or suboptimal levels of Lactobacillus was evaluated. Adaptation of cell to curb the oxidative damage in 146 HPV positive and 41 HPV negative with probiotic (Lacticaseibacillus rhamnosus Lcr35) supplementation and without was studied. Resistance of epithelial cells to damage was measured by the ratio of surviving, apoptotic, and dead nonapoptotic cells after three times of hydrogen peroxide treatment using a kit containing annexin V-fluorescein in combination with propidium iodide. If uninfected epithelial cells were in an environment with a physiological level of lactobacilli for significant duration, then these cells were more resilient to damage, and if they lost their viability, it was mainly due to apoptosis. Probiotic therapy also increased the resistance of uninfected epithelial cells to damage. HPV-infected epithelial cells were less resistant to damage at normal levels of lactobacilli compared with Lactobacillus deficiency. In HPV-positive patients with Lactobacillus deficiency, probiotic therapy decreased the resistance of infected epithelial cells to damage; the increase in cell death was mainly due to apoptosis.

SUMMARYA significant increase in the incidence of Candida-mediated infections has been observed in the last decade, mainly due to rising numbers of susceptible individuals. Recently, the World Health Organization published its first fungal pathogen priority list, with Candida species listed in medium, high, and critical priority categories. This review is a synthesis of information and recent advances in our understanding of two of these species-Candida albicans and Candida glabrata. Of these, C. albicans is the most common cause of candidemia around the world and is categorized as a critical priority pathogen. C. glabrata is considered a high-priority pathogen and has become an increasingly important cause of candidemia in recent years. It is now the second most common causative agent of candidemia in many geographical regions. Despite their differences and phylogenetic divergence, they are successful as pathogens and commensals of humans. Both species can cause a broad variety of infections, ranging from superficial to potentially lethal systemic infections. While they share similarities in certain infection strategies, including tissue adhesion and invasion, they differ significantly in key aspects of their biology, interaction with immune cells, host damage strategies, and metabolic adaptations. Here we provide insights on key aspects of their biology, epidemiology, commensal and pathogenic lifestyles, interactions with the immune system, and antifungal resistance.

Vaginally administered postbiotics derived from Lactobacillus were recently demonstrated to be effective in alleviating bacterial vaginosis and increasing pregnancy rates. However, their potential effect on sperm quality has not been well investigated. This controlled in vitro study aimed to assess the dose- and time-dependent effects of postbiotics derived from Lactobacillus rhamnosus PB01 (DSM 14870) on sperm quality parameters. The experiment was conducted in vitro to eliminate potential confounding factors from the female reproductive tract and vaginal microbiota. Sperm samples from 18 healthy donors were subjected to analysis using Computer-Aided Sperm Analysis (CASA) in various concentrations of postbiotics and control mediums at baseline, 60 min, and 90 min of incubation. Results indicated that lower postbiotic concentration (PB5) did not adversely affect sperm motility, kinematic parameters, sperm DNA fragmentation, and normal morphology at any time. However, concentrations exceeding 15% demonstrated a reduction in progressively motile sperm and a negative correlation with non-progressively motile sperm at all time points. These findings underscore the importance of balancing postbiotic dosage to preserve sperm motility while realizing the postbiotics' vaginal health benefits. Further research is warranted to understand the underlying mechanisms and refine practical applications in reproductive health.

The cervicovaginal microbiome is highly associated with women's health, with microbial communities dominated by Lactobacillus species considered optimal. Conversely, a lack of lactobacilli and a high abundance of strict and facultative anaerobes, including Gardnerella vaginalis, have been associated with adverse reproductive outcomes. However, how host-microbial interactions alter specific molecular pathways and impact cervical and vaginal epithelial function remains unclear. Using RNA-sequencing, we characterized the in vitro cervicovaginal epithelial transcriptional response to different vaginal bacteria and their culture supernatants. We showed that G. vaginalis upregulates genes associated with an activated innate immune response. Unexpectedly, G. vaginalis specifically induced inflammasome pathways through activation of NLRP3-mediated increases in caspase-1, IL-1β and cell death, while live L. crispatus had minimal transcriptomic changes on epithelial cells. L. crispatus culture supernatants resulted in a shift in the epigenomic landscape of cervical epithelial cells that was confirmed by ATAC-sequencing showing reduced chromatin accessibility. This study reveals new insights into host-microbe interactions in the lower reproductive tract and suggests potential therapeutic strategies leveraging the vaginal microbiome to improve reproductive health.

Urinary tract infections (UTIs) rank among the most prevalent bacterial infections in children. Probiotics appear to reduce the risk of recurrence of UTIs. This study aimed to evaluate whether probiotics containing Lactobacillus rhamnosus PL1 and Lactobacillus plantarum PM1 therapy prevent UTIs in the pediatric population compared to a placebo. A superiority, double-blind, randomized, controlled trial was conducted. In total, 54 children aged 3-18 years with recurrent UTIs or ≥one acute pyelonephritis and ≥one risk factor of recurrence of UTIs were randomly assigned (27 patients in each arm) to a 90-day probiotic or placebo arm. The age, sex, diagnosis, renal function, risk factors, and etiology of UTIs did not vary between the groups. During the intervention, 26% of children taking the probiotic had episodes of UTI, and it was not significantly less than in the placebo group. The number of UTI episodes during the intervention and the follow-up period decreased significantly in both groups, but the difference between them was insignificant. We observed a decrease in UTIs during the study of almost 50% in the probiotic group compared to the placebo group. Probiotics can be used as natural, safe prophylaxis for children with risk factors for UTIs in whom antibiotic prevention is not indicated.

Alterations in the vaginal microbiota, including both species composition and functional pathways, have been associated with HPV infection and progression of dysplasia to cervical cancer. To further explore this, shotgun metagenomic sequencing was used to taxonomically and functionally characterize the vaginal microbiota of women with and without cervical dysplasia. Women with histologically verified dysplasia (n = 177; low grade dysplasia (LSIL) n = 81, high-grade dysplasia (HSIL) n = 94, cancer n = 2) were compared with healthy controls recruited from the cervical screening programme (n = 177). Women with dysplasia had a higher vaginal microbial diversity, and higher abundances of Gardnerella vaginalis, Aerococcus christensenii, Peptoniphilus lacrimalis and Fannyhessea vaginae, while healthy controls had higher relative abundance of Lactobacillus crispatus. Genes involved in e.g. nucleotide biosynthesis and peptidoglycan biosynthesis were more abundant in women with dysplasia. Healthy controls showed higher abundance of genes important for e.g. amino acid biosynthesis, (especially L-lysine) and sugar degradation. These findings suggest that the microbiota may have a role in creating a pro-oncogenic environment in women with dysplasia. Its role and potential interactions with other components in the microenvironment deserve further exploration.

Vulvovaginal candidiasis (VVC) is the most common cause of vaginal discharge among women. The present study aimed to investigate the synergistic anticandidal effect of lactobacillus cultures supplemented with plant extracts. Among 600 isolates of lactic acid bacteria, 41 isolates exhibited inhibitory activity against Candida albicans ATCC10231. Six out of 41 cell-free supernatants demonstrated the most potent antibacterial and anticandidal activities. They also inhibited the clinical isolates of C. albicans, causing VVC and non-C. albicans. The synergistic effect between Lactobacillus crispatus 84/7 and Limosilactobacillus reuteri 89/4 was demonstrated by the lowest fractional inhibitory concentration index (FICI = 0.5). The synbiotic culture of bacterial combination, cultured with Jerusalem artichoke (H. tuberosus) extract, also exhibited the strongest inhibition against the tested C. albicans. Biofilm formation decreased after 12 h of incubation in the selected cell-free supernatants of this synbiotic culture. The anticandidal activity of crude extracts was lost after treatment with proteinase K and trypsin but not with heating conditions, suggesting that it may be a heat-stable substance. In conclusion, the combination of L. crispatus 84/7 and L. reuteri 89/4 with H. tuberosus may be a promising candidate for inhibiting Candida infection and biofilm formation, with the potential use as ingredients in vaginal biotherapeutic products.

Genitourinary syndrome of menopause (GSM) is the leading cause of vaginal symptoms in breast cancer survivors treated with aromatase inhibitors. However, there are currently no effective treatment options available for women with a history of breast cancer. Recent research has established that changes in the vaginal microbiome may be linked to GSM. Most studies have assessed the microbiome without accounting for the estrogen status. It remains unknown whether the vaginal microbiome differ among patients with a low estrogenic state with and without vulvovaginal symptoms. To address such research questions, our study compares the vaginal microbiomes among breast cancer survivors treated with aromatase inhibitors with and without vulvovaginal symptoms. A total of 50 breast cancer survivors treated with aromatase inhibitors were recruited, among whom 25 had vulvovaginal symptoms and 25 had no vulvovaginal symptoms. Vaginal swabs were collected. DNA extraction, followed by sequencing of the V3-V4 regions of the 16S ribosomal RNA gene, were performed. Differential abundance analysis was conducted by linear discriminant analysis effect size. Taxonomy assignment, alpha diversity and beta diversity were examined. The relative abundance of genus Sneathia and genus Gardnerella was significantly increased in vulvovaginal symptoms group with no differences in bacterial diversity and richness.

Cervicovaginal microbiome plays an important role in the persistence of HPV infection and subsequent disease development. However, cervicovaginal microbiota varied cross populations with different habits and regions. Identification of population-specific biomarkers from cervicovaginal microbiota and host metabolome axis may support early detection or surveillance of HPV-induced cervical disease at all sites. Therefore, in the present study, to identify HPV-specific biomarkers, cervicovaginal secretion and serum samples from HPV-infected patients (HPV group, n = 25) and normal controls (normal group, n = 17) in Xichang, China were collected for microbiome (16S rRNA gene sequencing) and metabolome (UHPLC-MS/MS) analysis, respectively.

The results showed that key altered metabolites of 9,10-DiHOME, α-linolenic acid, ethylparaben, glycocholic acid, pipecolic acid, and 9,12,13-trihydroxy-10(E),15(Z)-octadecadienoic acid, correlating with Sneathia (Sneathia_amnii), Lactobacillus (Lactobacillus_iners), Atopobium, Mycoplasma, and Gardnerella, may be potential biomarkers of HPV infection.

The results of current study would help to reveal the association of changes in cervicovaginal microbiota and serum metabolome with HPV infections.

Vaginal canal (VC) is exposed to the external environment affected by habitual factors like hygiene and sexual behaviour as well as physiological factors like puberty, menstrual cycle, pregnancy, child birth and menopause. Healthy VC harbours beneficial microflora supported by vaginal epithelium and cervical fluid. Connatural antimicrobial peptide (AMPs) of female reproductive tract (FRT) conjunctly with these beneficial microbes provide protection from a large number of infectious diseases. Such infections may either be caused by native microbes of the VC or transitory microbes like bacteria or virus which are not a part of VC microflora. This review highlight's the role of hormones, enzymes, innate immunological factors, epithelial cells and vaginal mucus that support beneficial microbes over infectious ones thus, helping to maintain homeostasis in VC and further protect the FRT. We also discuss the prospective use of vaginal probiotics and AMPs against pathogens which can serve as a potential cure for vaginal infections.

Although no study has directly shown the relationship between bacterial vaginosis (BV) and homocysteine (HCY), we still found some association between these two through extensive literature and data analysis. BV score was calculated by Nugent's method, less than equal to 6 is negative and greater than equal to 7 is positive. This article describes interrelationships we mined from data extracted by NHANES regarding BV and HCY under multiple covariates. We used two cycles of NHANES 2001-2002 and 2003-2004 in our study. We included 2398 participants in our study who recently completed the interview and the MEC tests. By investigating the relationship between BV and HCY under multivariate conditions, multiple linear regression analysis was performed. These factors may have influenced the results, such as ethnicity, age, education level, body mass index (BMI), etc. Serum vitamin B12, ferritin, percentage of segmented centrioles, and number of segmented centrioles were selected as potential covariates in our study. We observed that both the coarse model and the two adjusted models showed a high correlation between HCY and BV, and the correlation was positive. In the coarse model, OR = 1.26, 95% confidence interval (CI) 1.10, 1.44, P = 0.0018); HCY was positively correlated with BV (OR = 1.19, 95% confidence interval (CI) 1.05, 1.34, P = 0.0121). Multiple linear regression analysis was used to investigate the connection between BV and HCY under multivariate settings. The results of this study indicate that HCY is positively associated with the prevalence of BV and may play an important role in the prevention and management of BV.

The cervicovaginal microbiome is highly associated with women's health with microbial communities dominated by Lactobacillus spp. being considered optimal. Conversely, a lack of lactobacilli and a high abundance of strict and facultative anaerobes including Gardnerella vaginalis , have been associated with adverse reproductive outcomes. However, the molecular pathways modulated by microbe interactions with the cervicovaginal epithelia remain unclear. Using RNA-sequencing, we characterize the in vitro cervicovaginal epithelial transcriptional response to different vaginal bacteria and their culture supernatants. We showed that G. vaginalis upregulated genes were associated with an activated innate immune response including anti-microbial peptides and inflammasome pathways, represented by NLRP3-mediated increases in caspase-1, IL-1β and cell death. Cervicovaginal epithelial cells exposed to L. crispatus showed limited transcriptomic changes, while exposure to L. crispatus culture supernatants resulted in a shift in the epigenomic landscape of cervical epithelial cells. ATAC-sequencing confirmed epigenetic changes with reduced chromatin accessibility. This study reveals new insight into host-microbe interactions in the lower reproductive tract and suggest potential therapeutic strategies leveraging the vaginal microbiome to improve reproductive health.

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.

Each year, 15 million infants are born preterm (<37 weeks gestation), representing the leading cause of mortality for children under the age of five. Whilst there is no single cause, factors such as maternal genetics, environmental interactions, and the vaginal microbiome have been associated with an increased risk of preterm birth. Previous studies show that a vaginal microbiota dominated by Lactobacillus is, in contrast to communities containing a mixture of genera, associated with full-term birth. However, this binary principle does not fully consider more nuanced interactions between bacterial strains and the host. Here, through a combination of analyses involving genome-sequenced isolates and strain-resolved metagenomics, we identify that L. jensenii strains from preterm pregnancies are phylogenetically distinct from strains from full-term pregnancies. Detailed analysis reveals several genetic signatures that distinguish preterm birth strains, including genes predicted to be involved in cell wall synthesis, and lactate and acetate metabolism. Notably, we identify a distinct gene cluster involved in cell surface protein synthesis in our preterm strains, and profiling the prevalence of this gene cluster in publicly available genomes revealed it to be predominantly present in the preterm-associated clade. This study contributes to the ongoing search for molecular biomarkers linked to preterm birth and opens up new avenues for exploring strain-level variations and mechanisms that may contribute to preterm birth.

Bacterial vaginosis (BV) is a recurrent condition that affects millions of women worldwide. The use of probiotics is a promising alternative or an adjunct to traditional antibiotics for BV prevention and treatment. However, current administration regimens often require daily administration, thus contributing to low user adherence and recurrence. Here, electrospun fibers were designed to separately incorporate and sustain two lactic acid producing model organisms, Lactobacillus crispatus (L. crispatus) and Lactobacillus acidophilus (L. acidophilus). Fibers were made of polyethylene oxide and polylactic-co-glycolic acid in two different architectures, one with distinct layers and the other with co-spun components. Degradation of mesh and layered fibers was evaluated via mass loss and scanning electron microscopy. The results show that after 48 h and 6 days, cultures of mesh and layered fibers yielded as much as 108 and 109 CFU probiotic/mg fiber in total, respectively, with corresponding daily recovery on the order of 108 CFU/(mg·day). In addition, cultures of the fibers yielded lactic acid and caused a significant reduction in pH, indicating a high level of metabolic activity. The formulations did not affect vaginal keratinocyte viability or cell membrane integrity in vitro. Finally, mesh and layered probiotic fiber dosage forms demonstrated inhibition of Gardnerella, one of the most prevalent and abundant bacteria associated with BV, respectively resulting in 8- and 6.5-log decreases in Gardnerella viability in vitro after 24 h. This study provides initial proof of concept that mesh and layered electrospun fiber architectures developed as dissolving films may offer a viable alternative to daily probiotic administration.

Cervical cancer (CC) is caused by a persistent high-risk human papillomavirus (hrHPV) infection. The cervico-vaginal microbiome may influence the development of (pre)cancer lesions. Aim of the study was (i) to evaluate the new CC screening program in Germany for the detection of high-grade CC precursor lesions, and (ii) to elucidate the role of the cervico-vaginal microbiome and its potential impact on cervical dysplasia.

The microbiome of 310 patients referred to colposcopy was determined by amplicon sequencing and correlated with clinicopathological parameters.

Most patients were referred for colposcopy due to a positive hrHPV result in two consecutive years combined with a normal PAP smear. In 2.1% of these cases, a CIN III lesion was detected. There was a significant positive association between the PAP stage and Lactobacillus vaginalis colonization and between the severity of CC precursor lesions and Ureaplasma parvum.

In our cohort, the new cervical cancer screening program resulted in a low rate of additional CIN III detected. It is questionable whether these cases were only identified earlier with additional HPV testing before the appearance of cytological abnormalities, or the new screening program will truly increase the detection rate of CIN III in the long run. Colonization with U. parvum was associated with histological dysplastic lesions. Whether targeted therapy of this pathogen or optimization of the microbiome prevents dysplasia remains speculative.

The aim of this study was to evaluate the effect of Lactobacillus delbrueckii subsp. lactis (L.del) on vaginal microbiota (VM) dysbiosis and vaginal radiation injury in gynecologic cancer patients. The inhibitory effects of L.del on cervical cancer cells were also studied in vitro. Gynecologic cancer patients receiving radiotherapy were randomized into control and L.del intervention groups. The control group received radiotherapy, while the intervention group received radiotherapy and L.del intervention (1 capsule/day placed into the deep vagina from the first day of radiotherapy until the end of treatment). Vaginal swab samples were collected on the first day pre-treatment and the last day post-treatment. DNA from 54 patients was extracted and assessed by the 16S rRNA sequencing method. Radiotherapy resulted in vaginal microbiome dysbiosis characterized by increased phylogenetic diversity and increased abundance of Brevundimonas, Streptococcus and Prevotella, but a decreased abundance of Lactobacillus. Level 2 vaginal radiation injury was positively associated with the abundance of Brevundimonas and gram-negative non-fermenting bacteria. Administration of L.del attenuated the reduction of Lactobacillus while also inhibiting the abundance of Streptococcus and Prevotella, thereby ameliorating radiotherapy-related vaginal microbiota dysbiosis. CLD inhibited the in vitro proliferation of SiHa cells by altering the expression of BCL2, HPV16-E6, HPV16-E7, IL6, MAP7, BAX, Caspase-3, Caspase-9 and LTF. In conclusion, L. del application can alleviate radiation-induced vaginal dysbiosis and restore Lactobacillus dominance of the vaginal microbiome. Moreover, CLD was found to inhibit cell growth and promote the apoptosis of SiHa cells in vitro. The registration number for this clinical trial is ChiCTR1900021784.

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.

The objective of this study was to evaluate the effects of the use of intravaginal probiotics prepartum on the incidence risk of metritis postpartum and conception risk after first artificial insemination (AI). A total of 606 Holstein cows were enrolled 3 wk before their expected calving date from 2 farms. Cows were randomly assigned to either receive a 2-mL dose of a combination of 3 lactic acid bacteria (probiotic treatment) washed with approximately 2 mL of a sterile saline solution, into the vaginal canal twice weekly until parturition, or no intervention (control). Metritis diagnoses were carried out on 6 and 12 d postpartum. Vaginal discharge and rectal temperature were assessed, and vaginal discharge was scored on a scale from 1 to 4, where 1 = clear and 4 = fetid, purulent discharge. Metritis was defined as cows having a vaginal discharge score of 4 with or without fever (rectal temperature ≥39.5°C) on either 6 or 12 d postpartum, or both. Cows were bred after a 60-d voluntary waiting period primarily via the detection of estrus using automated activity monitors; cows not found in estrus were enrolled onto timed AI protocols to receive first breeding before 100 DIM. Pregnancy diagnosis was carried out at d 35 ± 7 post-AI on both farms. Data were analyzed via ANOVA using linear mixed regression models and survival analysis using a Cox proportional hazard model. Total incidence risk of metritis was 23.7% and 34.4% on farm A and farm B, respectively. Overall, the incidence of metritis was not different between treatment groups (control: 41.6 ± 3.8%; probiotic: 38.6 ± 4.0%); however, an interaction by farm was detected, where the probiotic treatment reduced metritis on one farm but not on the other. Conception risk after first AI was not affected by treatment. However, we detected an interaction between parity and treatment, where multiparous cows receiving the probiotic treatment were more likely to become pregnant compared with multiparous cows within the control group (hazard ratio: 1.33; 95% confidence interval: 1.10-1.60); no effect of probiotic treatment was found on the hazard of pregnancy for primiparous cows. In addition, the probiotic treatment was associated with an increased proportion of cows being detected in estrus for the first AI postpartum. In conclusion, vaginal probiotic treatment applied during the 3 wk prepartum was associated with a decreased incidence of metritis on one farm but not the other, suggesting that farm management may be a key player influencing treatment efficacy. Overall, probiotic treatment was found to have only limited effects on fertility in the current study.

The vaginal microbiome has emerged as potentially influencing the natural history of Human Papillomavirus (HPV) infections and their clinical impact. We aimed to characterize the vaginal microbiome in samples from 807 high-risk HPVs (Hr-HPV) positive women with a mean age of 41.45 ± 10.79 years who participated in the Regional Cervical Cancer Screening Program from the Northern Region of Portugal. Microbiome analysis was performed with commercial kits for the detection of 21 microorganisms. The most frequent microorganisms were Ureaplasma parvum (52.5%), Gardnerella vaginalis (GV) (34.5%), Atopobium vaginae (AV) (32.6%), Lacto (30.7%), and Mycoplasma hominis (MH) (23.5%). The distribution according to age reveals that MH, Mega1, GV, BVab2, AV, and Mob were more prevalent in women older than 41 years of age (p < 0.050), while Lacto is significantly decreased in this group (23.5% vs. 39.4%, p < 0.001; RR = 0.47). The risk analysis showed that Hr-HPV-16/-18 and Hr-HPV-9val genotypes are associated with an increased risk of developing cervical abnormalities, while Lacto (p < 0.001; odd ratio [OR] = 0.33), GV (p = 0.0111; OR = 0.41), AV (p = 0.033; OR = 0.53) and Mob (p = 0.022; OR = 0.29) are associated with protection. Similar results were found for the risk of development atypical squamous cells cannot exclude HSIL/high-grade squamous intraepithelial lesion. Overall, the multivariate analysis confirmed that lactobacillus and bacteria associated with bacterial vaginosis (GV, AV, and Mob) are associated with protection against the development of cervical abnormalities. This study provides important data to be included in the future management of risk stratification for Hr-HPV-positive women.

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.

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

Vaginal lactobacilli are recognized as important drivers of genital health including protection against bacterial vaginosis and sexually transmitted infections. Lactobacillus iners is distinct from L. crispatus, L. gasseri, and L. jensenii by its high global prevalence in vaginal microbiomes, relatively small genome, production of only L-lactic acid, and inconsistent associations with genital health outcomes. In this review, we summarize our current understanding of the role of L. iners in the vaginal microbiome, highlight the importance of strain-level consideration for this species, and explain that while marker gene-based characterization of the composition of the vaginal microbiota does not capture strain-level resolution, whole metagenome sequencing can aid in expanding our understanding of this species in genital health.

L. iners exists in the vaginal microbiome as a unique combination of strains. The functional repertoires of these strain combinations are likely wide and contribute to the survival of this species in a variety of vaginal microenvironments. In published studies to date, strain-specific effects are aggregated and may yield imprecise estimates of risk associated with this species.

The worldwide high prevalence of Lactobacillus iners warrants more research into its functional roles in the vaginal microbiome and how it may directly impact susceptibility to infections. By incorporating strain-level resolution into future research endeavors, we may begin to appreciate L. iners more thoroughly and identify novel therapeutic targets for a variety of genital health challenges.

Lactobacilli are essential microbiota that maintain a healthy, balanced vaginal environment. Vaginitis is a common infection in women during their reproductive years. Many factors are associated with vaginitis; one of them is the imbalance of microbiota in the vaginal environment. This study aimed to evaluate the antimicrobial properties of Lactobacillus delbrueckii 45E (Ld45E) against several species of bacteria, namely, Group B Streptococcus (GBS), Escherichia coli, Klebsiella spp., and Candida parapsilosis, as well as to determine the concentration of interleukin-17 (IL-17) in the presence of Ld45E.

The probiotic characteristics of Ld45E were evaluated by examining its morphology, pH tolerance, adhesive ability onto HeLa cells, hemolytic activity, antibiotic susceptibility, and autoaggregation ability. Then, the antimicrobial activity of Ld45E was determined using Ld45E culture, cell-free supernatant, and crude bacteriocin solution. Co-aggregation and competition ability assays against various pathogens were conducted. The immunoregulatory effects of Ld45E were analyzed by measuring the proinflammatory cytokine IL-17. A p-value less than 0.05 was considered statistical significance.

Ld45E is 3-5 mm in diameter and round with a flat-shaped colony. pH 4 and 4.5 were the most favorable range for Ld45E growth within 12 h of incubation. Ld45E showed a strong adhesion ability onto HeLa cells (86%) and negative hemolytic activities. Ld45E was also sensitive to ceftriaxone, cefuroxime, ciprofloxacin, and doxycycline. We found that it had a good autoaggregation ability of 80%. Regarding antagonistic properties, Ld45E culture showed strong antimicrobial activity against GBS, E. coli, and Klebsiella spp. but only a moderate effect on C. parapsilosis. Cell-free supernatant of Ld45E exerted the most potent inhibitory effects at 40 °C against all genital pathogens, whereas bacteriocin showed a robust inhibition at 37 °C and 40 °C. The highest co-aggregation affinity was observed with GBS (81%) and E. coli (40%). Competition ability against the adhesion of GBS (80%), E. coli (76%), Klebsiella (72%), and C. parapsilosis (58%) was found. Ld45E was able to reduce the induction of the proinflammatory protein IL-17.

Ld45E possessed antimicrobial and immunoregulatory properties, with better cell-on-cell activity than supernatant activity. Thus, Ld45E is a potential probiotic candidate for adjunct therapy to address vaginal infections.

It is generally accepted that microorganisms can colonize a non-pathological endometrium. However, in a clinical setting, endometrial samples are always collected by passing through the vaginal-cervical route. As such, the vaginal and cervical microbiomes can easily cross-contaminate endometrial samples, resulting in a biased representation of the endometrial microbiome. This makes it difficult to demonstrate that the endometrial microbiome is not merely a reflection of contamination originating from sampling. Therefore, we investigated to what extent the endometrial microbiome corresponds to that of the vagina, applying culturomics on paired vaginal and endometrial samples. Culturomics could give novel insights into the microbiome of the female genital tract, as it overcomes sequencing-related bias. Ten subfertile women undergoing diagnostic hysteroscopy and endometrial biopsy were included. An additional vaginal swab was taken from each participant right before hysteroscopy. Both endometrial biopsies and vaginal swabs were analyzed using our previously described WASPLab-assisted culturomics protocol. In total, 101 bacterial and two fungal species were identified among these 10 patients. Fifty-six species were found in endometrial biopsies and 90 were found in vaginal swabs. On average, 28 % of species were found in both the endometrial biopsy and vaginal swab of a given patient. Of the 56 species found in the endometrial biopsies, 13 were not found in the vaginal swabs. Of the 90 species found in vaginal swabs, 47 were not found in the endometrium. Our culturomics-based approach sheds a different light on the current understanding of the endometrial microbiome. The data suggest the potential existence of a unique endometrial microbiome that is not merely a presentation of cross-contamination derived from sampling. However, we cannot exclude cross-contamination completely. In addition, we observe that the microbiome of the vagina is richer in species than that of the endometrium, which contradicts the current sequence-based literature.