Assessment of the capacity of Lactobacillus to inhibit the growth of uropathogens and block their adhesion to vaginal epithelial cells

Vaginal microbiome dysbiosis as a novel noninvasive biomarker for detection of chronic endometritis in infertile women

OBJECTIVE

To identify the vaginal microbial signature in women with chronic endometritis (CE) and investigate the potential of vaginal microbiome characterization as a novel diagnostic tools for CE.

METHODS

A cross-sectional study was conducted to compare the characteristics of the vaginal microbiome in 98 women who underwent endometrial biopsy for routine clinical inspection of infertility (49 women diagnosed with CE and 49 with non-CE). The vaginal microbiome was analyzed using 16S ribosomal RNA gene amplicon sequencing. The study included an analysis of diversity, bacterial abundance, and microbial function. In addition, microbial markers were identified, and a CE classifier was developed.

RESULTS

The relative abundances of genera, including Bifidobacterium, Prevotella and Gardnerella, were found to be different between the two groups. Analysis of the Kyoto Encyclopedia of Genes and Genomes pathways reported differential expression in metabolism-related pathways in the two groups. We identified four microbial markers of CE (Enterobacter, Prevotella, Faecalibacterium, and Phascolarctobacterium) and developed a predictive classifier for diagnosing CE, achieving an area under the curve of 83.26%.

CONCLUSION

The results of the current study revealed that, compared with the non-CE controls, patients with CE have a different vaginal microbiota, highlighting the diagnostic significance of the vaginal microbiome as a promising noninvasive biomarker in detecting CE.

Biogenic amine tryptamine in human vaginal probiotic isolates mediates matrix inhibition and thwarts uropathogenic E. coli biofilm

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.

Lactobacillus rhamnosus PL1 and Lactobacillus plantarum PM1 versus Placebo as Prophylaxis for Recurrence of Urinary Tract Infections in Children

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.

Prophylactic application of vaginal lactic acid bacteria against urogenital pathogens and its prospective use in sanitary suppositories

Beneficial and pathogenic microbes coexist in the vaginal canal, where a diminishing population of lactic acid bacteria may cause recurring urogenital infections. Probiotic bacteria Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus vaginalis, and pathogenic microbes Enterococcus faecalis, Enterobacter cloacae, Shigella sp., Staphylococcus epidermidis, and Escherichia fergusonii were isolated from vaginal swabs. Lactobacillus sp. and their probiotic culture free supernatant (PCFS) inhibited the growth of the above-mentioned urogenital pathogens. L. crispatus produced both lactic acid and hydrogen peroxide, exhibiting the best antimicrobial potential against the studied pathogens. Lyophilized L. crispatus had a shelf life of 12 months and the lyophilized PCFS also retained its antibacterial property with a minimum inhibition concentration of 1 μg/μL. Carboxy-methyl cellulose-alginate, a green alternative to super-absorbent polymers, was encapsulated with L. crispatus cells. The probiotic in its encapsulated state retained its viability for 21 days, and the bead showed 30% solvent absorptive capacity. PCFS-laced non-woven fabric displayed antibacterial property with no change in its physicochemical properties. These probiotic and postbiotic formulations have excellent prophylactic potential for urogenital infections. Such formulations can be exploited as additives in sanitary suppositories to enhance vaginal health.

Mesh and layered electrospun fiber architectures as vehicles for Lactobacillus acidophilus and Lactobacillus crispatus intended for vaginal delivery

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.

The urobiome in men and women: a clinical review

BACKGROUND

Antibiotic therapy alone is unable to control recurrent urinary tract infection (UTI); uropathogens have become multiresistant, and alternative strategies are needed. Far from sterile, the urinary tract contains various low-biomass microbiota, some of whose members appear to protect against clinical UTI.

OBJECTIVES

This narrative review summarizes (a) the current knowledge of male and female urobiomes in healthy and diseased states, as well as their interplay among sexual partners and (b) clinical trials to date assessing probiotic and other nonantibiotic measures to reduce UTI.

SOURCES

We used the PubMed interface to search Ovid Medline for articles describing urogenital flora, UTI, UTI dysbiosis, the effects of sexual intercourse on urogenital flora, and clinical trials of probiotics as UTI prophylaxis.

CONTENT

The healthy urobiome of women contains several Lactobacillus species, some of which may impede Escherichia coli growth in the urinary tract. Although Lactobacilli have been found in male urethral microbiota, their presence in male bladder microbiota is less certain. Distal male urethral and vaginal microbiomes of male and sexual female partners influence one another, but more research is needed on the direct interplay of their full urobiomes. Clinical trials assessing the therapeutic potential of Lactobacilli have been largely underpowered and highly varied in tested formulations and routes and frequencies of administration; as such, they have failed to show a clear benefit. Faecal microbiota transplantation for recurrent Clostridium difficile infection was shown, in a retrospective study of seven patients, to reduce recurrent UTI as a side effect.

IMPLICATIONS

The urobiome in men and women is complex, variable, and still understudied. Although there is hope that Lactobacilli and faecal microbial transplantation could be future nonantibiotic options for recurrent UTI, both require more pharmacologic and clinical research to identify optimal preparations and routes of administration.

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.

Possible Therapeutic Mechanisms and Future Perspectives of Vaginal Microbiota Transplantation

Microbial communities inhabiting the human body play a crucial role in protecting the host against pathogens and inflammation. Disruptions to the microbial composition can lead to various health issues. Microbial transfer therapy (MTT) has emerged as a potential treatment option to address such issues. Fecal microbiota transplantation (FMT) is the most widely used form of MTT and has been successful in treating several diseases. Another form of MTT is vaginal microbiota transplantation (VMT), which involves transferring vaginal microbiota from a healthy female donor to a diseased patient's vaginal cavity with the goal of restoring normal vaginal microbial composition. However, VMT has not been extensively studied due to safety concerns and a lack of research. This paper explores the therapeutic mechanisms of VMT and discusses future perspectives. Further research is necessary to advance the clinical applications and techniques of VMT.

Etiology of recurrent cystitis in postmenopausal women based on vaginal microbiota and the role of Lactobacillus vaginal suppository

Background

The vaginal microbiota can be altered by uropathogenic bacteria associated with recurrent cystitis (RC), and the vaginal administration of Lactobacillus have suggested certain effects to prevent RC. The relationship between vaginal microbiota and the development of RC has not been elucidated. We aimed to clarify the etiology of RC from vaginal microbiota and importance of vaginal Lactobacillus.

Methods

Vaginal samples obtained from 39 postmenopausal women were classified into four groups: healthy controls; uncomplicated cystitis; RC; and prevention (prevented RC by Lactobacillus crispatus-containing vaginal suppositories). Principal coordinate analysis and beta-diversity analysis was used to assess 16S rRNA gene sequencing data from the vaginal microbiome.

Results

Cluster analysis divided the vaginal bacterial communities among 129 vaginal samples into three clusters (A, B, and C). Fourteen of 14 (100%) samples from the RC group and 51 of 53 (96%) samples from the prevention group were in clusters B and C, while 29 of 38 (76%) samples from the healthy group and 14 of 24 (58%) samples from the uncomplicated cystitis group were in cluster A. The principal coordinate analysis showed that plots in the uncomplicated cystitis group were similar to the healthy group, indicating a large separation between the RC group and the uncomplicated cystitis group. On beta-diversity analysis, there were significant differences between the healthy group and the uncomplicated cystitis group (p = 0.045), and between the RC group and the uncomplicated cystitis group or the healthy group (p = 0.001, p = 0.001, respectively). There were no significant differences between the RC group and the prevention group (p = 0.446). The top six taxa were as follows: Prevotella, Lactobacillus, Streptococcus, Enterobacteriaceae, Anaerococcus, and Bifidobacterium. Among patients with RC, Lactobacillus was undetectable before administration of suppositories, while the median relative abundance of Lactobacillus was 19% during administration of suppositories (p = 0.0211), reducing the average cystitis episodes per year (6.3 vs. 2.4, p = 0.0015).

Conclusion

The vaginal microbiota of postmenopausal women with RC is differed from healthy controls and uncomplicated cystitis in terms of lack of Lactobacillus and relatively dominant of Enterobacteriaceae. Vaginal administration of Lactobacillus-containing suppositories can prevent RC by stabilizing vaginal dysbiosis and causing a loss of pathogenic bacteria virulence.

Limosilactobacillus fermentum 3872 That Produces Class III Bacteriocin Forms Co-Aggregates with the Antibiotic-Resistant Staphylococcus aureus Strains and Induces Their Lethal Damage

LF3872 was isolated from the milk of a healthy lactating and breastfeeding woman. Earlier, the genome of LF3872 was sequenced, and a gene encoding unique bacteriocin was discovered. We have shown here that the LF3872 strain produces a novel thermolabile class III bacteriolysin (BLF3872), exhibiting antimicrobial activity against antibiotic-resistant Staphylococcus aureus strains. Sequence analysis revealed the two-domain structural (lysozyme-like domain and peptidase M23 domain) organization of BLF3872. At least 25% residues of this protein are expected to be intrinsically disordered. Furthermore, BLF3872 is predicted to have a very high liquid-liquid phase separation. According to the electron microscopy data, the bacterial cells of LF3872 strain form co-aggregates with the S. aureus 8325-4 bacterial cells. LF3872 produced bacteriolysin BLF3872 that lyses the cells of the S. aureus 8325-4 mastitis-inducing strain. The sensitivity of the antibiotic-resistant S. aureus collection strains and freshly isolated antibiotic-resistant strains was tested using samples from women with lactation mastitis; the human nasopharynx and oral cavity; the oropharynx of pigs; and the cows with a diagnosis of clinical mastitis sensitive to the lytic action of the LF3872 strain producing BLF3872. The co-cultivation of LF3872 strain with various antibiotic-resistant S. aureus strains for 24 h reduced the level of living cells of these pathogens by six log. The LF3872 strain was found to be able to co-aggregate with all studied S. aureus strains. The cell-free culture supernatant of LF3872 (CSLF3872) induced S. aureus cell damage and ATP leakage. The effectiveness of the bacteriolytic action of LF3872 strain did not depend on the origin of the S. aureus strains. The results reported here are important for the creation of new effective drugs against antibiotic-resistant strains of S. aureus circulating in humans and animals.

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

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

The immune responses to different Uropathogens call individual interventions for bladder infection

Urinary tract infection (UTI) caused by uropathogens is the most common infectious disease and significantly affects all aspects of the quality of life of the patients. However, uropathogens are increasingly becoming antibiotic-resistant, which threatens the only effective treatment option available-antibiotic, resulting in higher medical costs, prolonged hospital stays, and increased mortality. Currently, people are turning their attention to the immune responses, hoping to find effective immunotherapeutic interventions which can be alternatives to the overuse of antibiotic drugs. Bladder infections are caused by the main nine uropathogens and the bladder executes different immune responses depending on the type of uropathogens. It is essential to understand the immune responses to diverse uropathogens in bladder infection for guiding the design and development of immunotherapeutic interventions. This review firstly sorts out and comparatively analyzes the immune responses to the main nine uropathogens in bladder infection, and summarizes their similarities and differences. Based on these immune responses, we innovatively propose that different microbial bladder infections should adopt corresponding immunomodulatory interventions, and the same immunomodulatory intervention can also be applied to diverse microbial infections if they share the same effective therapeutic targets.

Heritable vaginal bacteria influence immune tolerance and relate to early-life markers of allergic sensitization in infancy

Maternal asthma status, prenatal exposures, and infant gut microbiota perturbation are associated with heightened risk of atopy and asthma risk in childhood, observations hypothetically linked by intergenerational microbial transmission. Using maternal vaginal (n = 184) and paired infant stool (n = 172) samples, we identify four compositionally and functionally distinct Lactobacillus-dominated vaginal microbiota clusters (VCs) that relate to prenatal maternal health and exposures and infant serum immunoglobulin E (IgE) status at 1 year. Variance in bacteria shared between mother and infant pairs relate to VCs, maternal allergy/asthma status, and infant IgE levels. Heritable bacterial gene pathways associated with infant IgE include fatty acid synthesis and histamine and tryptophan degradation. In vitro, vertically transmitted Lactobacillus jensenii strains induce immunosuppressive phenotypes on human antigen-presenting cells. Murine supplementation with L. jensenii reduces lung eosinophils, neutrophilic expansion, and the proportion of interleukin-4 (IL-4)⁺ CD4⁺ T cells. Thus, bacterial and atopy heritability are intimately linked, suggesting a microbial component of intergenerational disease transmission.

Commensal Urinary Lactobacilli Inhibit Major Uropathogens In Vitro With Heterogeneity at Species and Strain Level

The human urinary microbiome is thought to affect the development and progression of urinary tract infections (UTI), particularly recurrent UTIs in aging populations of women. To understand the possible interactions of urinary pathogens with commensal bacteria inhabiting the aging bladder, we conducted an initial functional assessment of a representative set of urinary lactobacilli that dominate this niche in postmenopausal women. We created a repository of urinary bladder bacteria isolated via Enhanced Quantitative Urinary Culture (EQUC) from healthy postmenopausal women, as well as those with a culture-proven recurrent UTI (rUTI) diagnosis. This repository contains lactobacilli strains from eight different species. As many other lactobacilli are known to inhibit human pathogens, we hypothesized that some urinary lactobacilli will have similar abilities to inhibit the growth of typical uropathogens and thus, provide a link between the urinary microbiome and the predisposition to the rUTI. Therefore, we screened the urinary lactobacilli in our repository for their ability to inhibit model uropathogens in vitro. We observed that many urinary isolates strongly inhibit model strains of gram-negative Escherichia coli and Klebsiella pneumoniae but demonstrate less inhibition of gram-positive Enterococcus faecalis. The observed inhibition affected model strains of uropathogens as well as clinical and multidrug-resistant isolates of those species. Our preliminary analysis of inhibition modes suggests a combination of pH-dependent and cell-dependent inhibition. Overall, inhibition strongly varies among species and strains of urinary lactobacilli. While the strength of the inhibition is not predictive of health outcomes in this limited repository, there is a high level of species and strain diversity that warrants future detailed investigations.

Effect of luxS encoding a synthase of quorum-sensing signal molecule AI-2 of Vibrio vulnificus on mouse gut microbiome

Autoinducer-2 (AI-2), a quorum-sensing signal molecule from the human pathogen Vibrio vulnificus, was assessed for its effect on the gut microbiome of mice. For this, we employed 16S rRNA sequencing to compare the gut microbiome of mice infected with either wild-type V. vulnificus or with the isotype ΔluxS that has a deletion in luxS which encodes the biosynthetic function of AI-2. The relative ratio of wild-type Vibrio species in the jejunum and ileum of mice infected with the wild type was significantly higher than that in mice infected with ΔluxS, suggesting that AI-2 plays an important role in the colonization of V. vulnificus in the small intestine. The bacterial composition in the gut of mice infected with ΔluxS comprises a higher proportion of Firmicutes, composed mainly of Lactobacillus, compared to the mice infected with wild-type cells. In the large intestine, Vibrio species were barely detected regardless of genetic background. Three Lactobacillus spp. isolated from fecal samples from mice infected with ΔluxS manifested significant antibacterial activities against V. vulnificus. Culture supernatants from these three species were dissolved by HPLC, and a substance in fractions showing inhibitory activity against V. vulnificus was determined to be lactic acid. Our results suggest that luxS in V. vulnificus affects not only the ability of the species to colonize the host gut but also its susceptibility to the growth-inhibiting activity of commensal bacteria including Lactobacillus. KEY POINTS: • Gut microbiomes of ΔluxS-infected and WT Vibrio-infected mice differed greatly. • Difference was most prominent in the jejunum and ileum compared to the duodenum or large intestine. • In the small and large intestines of mice, the relative proportions of Vibrio and Lactobacillus species showed a negative relationship. • Effector molecules produced by Lactobacillus in mouse gut inhibit Vibrio growth.

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.

Contribution of Lactobacillus iners to Vaginal Health and Diseases: A Systematic Review

Lactobacillus iners, first described in 1999, is a prevalent bacterial species of the vaginal microbiome. As L. iners does not easily grow on de Man-Rogosa-Sharpe agar, but can grow anaerobically on blood agar, it has been initially overlooked by traditional culture methods. It was not until the wide application of molecular biology techniques that the function of L. iners in the vaginal microbiome was carefully explored. L. iners has the smallest genome among known Lactobacilli and it has many probiotic characteristics, but is partly different from other major vaginal Lactobacillus species, such as L. crispatus, in contributing to the maintenance of a healthy vaginal microbiome. It is not only commonly present in the healthy vagina but quite often recovered in high numbers in bacterial vaginosis (BV). Increasing evidence suggests that L. iners is a transitional species that colonizes after the vaginal environment is disturbed and offers overall less protection against vaginal dysbiosis and, subsequently, leads to BV, sexually transmitted infections, and adverse pregnancy outcomes. Accordingly, under certain conditions, L. iners is a genuine vaginal symbiont, but it also seems to be an opportunistic pathogen. Further studies are necessary to identify the exact role of this intriguing species in vaginal health and diseases.

Development of bifunctional vaginal suppositories by joint use terconazole and probiotic for treatment and prophylaxis of vulvovaginal candidiasis

OBJECTIVE

The objective of this article is the creation and investigation of bifunctional suppositories that are endowed with antifungal and probiotic properties intended for the treatment of vulvovaginal candidiasis (VVC) and colonization of the vaginal cavity by powerful lactobacilli.

MATERIALS AND METHODS

Freeze-dried Lactobacillus delbrueckii MH10 was used as a probiotic, which is an active producer of H₂O₂ isolated from a healthy woman's vagina. Hydrophilic PEG 4000/400, amphiphilic Suppocire AP, and lipophilic Novata ABPH bases were used for the preparation of vaginal suppositories and each included 80 mg terconazole and 25 mg (∼10⁹ CFU) lactobacilli. The release kinetic of active agents from suppositories was studied using the British Pharmacopeia's basket dissolution method, and the physicochemical properties were studied using known methods. Bioadhesion of suppositories was evaluated by flow rate from polyacrylamide substrate inclined at 60°. Antagonism of lactobacillus against fungi was studied using the disk diffusion method and joint cultivation in simulated vaginal fluid.

RESULTS

The release rate of active ingredients from the suppositories was PEG 4000/400 > Suppocire AP > Novata ABPH in decreasing order. Suppositories made of Suppocire AP possessed higher adhesion ability to artificial mucosa and longer shelf life. It was revealed that during joint cultivation L. delbrueckii MH10 kills more than 90% of C. albicans population.

CONCLUSIONS

Due to its physicochemical, biopharmaceutical, and bioadhesive properties, the base Suppocire AP is preferable for manufacturing vaginal bifunctional suppositories. Lactobacilli kill C. albicans by coaggregating and direct releasing hydrogen peroxide onto target cells.

Vaginal microbiota affects urinary tract infection risk in women with systemic lupus erythematosus: a pilot cross-sectional study from Thailand

OBJECTIVE

The risk factors associated with urinary tract infections (UTIs) in patients with SLE remain uncertain. We evaluated the vaginal microbiota pattern and its potential UTI-associated risk factors.

METHODS

A pilot cross-sectional study of patients with SLE was conducted at Ramathibodi Hospital, Bangkok, Thailand, during 2019-2020. Patients' demographic data and relevant information were collected. Vaginal microbiota was assessed in all patients and in 10 healthy volunteers.

RESULTS

Fifty-two patients were enrolled (mean age: 46.1 years). All patients had SLE that was in low disease activity. As per the Simpson_e index, the within-group alpha diversity of the vaginal microbiota was low in the SLE with UTI and SLE receiving trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis groups. Multivariate logistic regression analysis revealed that TMP-SMX prophylaxis (adjusted OR (AOR), 30.96; 95% CI 3.63 to 264.11; p=0.002), elevated C3 levels (AOR, 35.33; 95% CI 1.33 to 936.67; p=0.033) and presence of Veillonella dispar in the vaginal microbiota (AOR, 6.68; 95% CI 1.27 to 35.07; p=0.025) were associated with UTI.

CONCLUSIONS

The vaginal microbiota diversity differed between patients with lupus with and without UTI, and unnecessary administration of TMP-SMX prophylaxis may affect the alpha diversity of the vaginal microbiota.

Deep insights into urinary tract infections and effective natural remedies

Background

Urinary tract infection (UTI) is a common occurrence in females, during pregnancy, and in peri- and postmenopausal women. UTIs are associated with significant morbidity and mortality, and they affect the quality of life of the affected patients. Antibiotic therapy is an effective approach and reduces the duration of symptoms. Development of resistance, adverse effects of antibiotics, and other associated problems lead to establishing the research framework to find out the alternative approaches in controlling UTIs. Natural approaches have been extensively used for the management of various diseases to improve symptoms and also improve general health.

Main body

Different databases were employed to identify studies reporting on natural options including herbal medicines, vitamins, trace elementals, sugars, and probiotics without time limitations.

Conclusion

Herbal medicines can be effective at the first sign of the infection and also for short-term prophylaxis. Using vitamins, trace elementals, and/or sugars is an effective approach in preventing UTIs, and a combination of them with other antibacterial agents shows positive results. Probiotics have great potential for the threat of antibiotic over-usage and the prevalence of antibiotic-resistant microorganisms. This study may be of use in developing the efficient formulation of treatment of UTI.

A single intravesical instillation of Lactobacillus rhamnosus GG is safe in children and adults with neuropathic bladder: A phase Ia clinical trial

Context/objective: Manipulation of the microbiome is an emerging approach to promote health. We conducted a Phase Ia safety study of a single bladder instillation of probiotics in asymptomatic patients with neuropathic bladder to determine the tolerability and safety of a single Lactobacillus instillation.Design: Phase Ia safety study.Setting: Outpatient rehabilitation clinic at a rehabilitation hospital (adults) and urology clinic at a free-standing children's hospital (children).Participants: Ten patients with neuropathic bladder were included: five children with spina bifida and five adults with spinal cord injury.Interventions: A single Lactobacillus rhamnosus GG (Culturelle, 20 billion live organisms) instillation.Outcome measures: After the instillation, participants self-monitored symptoms using the Urinary Symptoms Questionnaire for People with Neuropathic Bladder using Intermittent Catheterization daily for one week. Repeat urinalysis, urine culture, and 16S bacterial rRNA-based microbiome analyses were performed 7-10 days after instillation.Results: Probiotic instillation was well-tolerated. One child had upper respiratory tract symptoms during the trial, and two had transient cloudy urine. No adults reported any symptoms following instillation. Lactobacillus did not grow on culture post-instillation. There were differences in beta diversity of the urine microbiome in children vs. adults with neuropathic bladder (P < 0.0156). Lactobacillus was present in the pre-instillation urinary microbiomes all of the adults and 4 out of 5 of the pediatric subjects, and identified in 4 out of 5 of both the adult and pediatric subjects' post-instillation urinary microbiomes.Conclusion: Intravesical instillation of Culturelle probiotic may be safe and well-tolerated in patients with neuropathic bladder.

Human Pathogenic Candida Species Respond Distinctively to Lactic Acid Stress

Several Candida species are opportunistic human fungal pathogens and thrive in various environmental niches in and on the human body. In this study we focus on the conditions of the vaginal tract, which is acidic, hypoxic, glucose-deprived, and contains lactic acid. We quantitatively analyze the lactic acid tolerance in glucose-rich and glucose-deprived environment of five Candida species: Candidaalbicans, Candida glabrata, Candida parapsilosis, Candida krusei and Candida tropicalis. To characterize the phenotypic space, we analyzed 40–100 clinical isolates of each species. Each Candida species had a very distinct response pattern to lactic acid stress and characteristic phenotypic variability. C. glabrata and C. parapsilosis were best to withstand high concentrations of lactic acid with glucose as carbon source. A glucose-deprived environment induced lactic acid stress tolerance in all species. With lactate as carbon source the growth rate of C. krusei is even higher compared to glucose, whereas the other species grow slower. C. krusei may use lactic acid as carbon source in the vaginal tract. Stress resistance variability was highest among C. parapsilosis strains. In conclusion, each Candida spp. is adapted differently to cope with lactic acid stress and resistant to physiological concentrations.

Understanding the potential of lactobacilli in recurrent UTI prevention

Urinary tract infections (UTIs) are one of the most common infections in women. The only proven preventive strategy for recurrent UTIs is prophylactic antibiotics. Given growing antibiotic resistance, the use of probiotics has been proposed as an alternative to antibiotics. Herein, we discuss the current evidence to support the possibility that exogenous lactobacilli may limit the pathogenicity of uropathogens such as E. coli. Probiotics appear to have a significant potential in prevention of recurrent UTI, however, additional data are needed to understand how they can be effectively used in clinical practice.

Anti-Biofilm Properties of Saccharomyces cerevisiae CNCM I-3856 and Lacticaseibacillus rhamnosus ATCC 53103 Probiotics against G. vaginalis

Bacterial vaginosis (BV) is characterized by the presence of a polymicrobial biofilm where Gardnerella vaginalis plays a key role. Previously, we demonstrated that Saccharomyces cerevisiae CNCM (French National Collection of Cultures of Microorganisms) I-3856 is helpful in resolving experimental simulated BV in mice. In this study, we analyzed its capacity to affect G. vaginalis biofilms and to potentiate the activity of standard antimicrobial agents. We also investigated the anti-biofilm activity of Lacticaseibacillus rhamnosus GG (ATCC 53103), a well-known strain for its intestinal healthy benefits. Biofilm biomass was assessed by crystal violet staining, and G. vaginalis viability was assessed by a colony forming unit (CFU) assay. Here, for the first time, we demonstrated that S. cerevisiae CNCM I-3856 as well as L. rhamnosus GG were able (i) to significantly inhibit G. vaginalis biofilm formation, (ii) to markedly reduce G. vaginalis viability among the biomass constituting the biofilm, (iii) to induce disaggregation of preformed biofilm, and (iv) to kill a consistent amount of bacterial cells in a G. vaginalis preformed biofilm. Furthermore, S. cerevisiae CNCM I-3856 strongly potentiates the metronidazole effect on G. vaginalis biofilm viability. These results suggest that S. cerevisiae CNCM I-3856 as well as L. rhamnosus GG could be potential novel therapeutic agents against bacterial vaginosis.

The Development of High-Quality Multispecies Probiotic Formulations: From Bench to Market

Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. To date, there is an increasing number of commercially available products containing probiotics on the market. Probiotics have been recommended by health care professionals for reasons ranging from their long-term immunomodulatory effects to proven benefits in the management of different health conditions. For probiotic products, there are several important aspects that determine the success rate of the development from bench to market. The aim of this review is to explore how the current knowledge on microbe–microbe and host–microbe interactions can be used to develop high-quality, evidence-based probiotic formulations, specifically probiotic dietary supplements, with a focus on the selection of safe strains with relevant functional properties. In addition, we will highlight aspects of the probiotic manufacturing process that need to be considered during the product development and the subsequent manufacturing process to guarantee consistent efficacy of a probiotic product. For each high-quality probiotic formulation, it is important to screen multiple strains, and select only those strains that show relevant functional properties and that can be considered safe for human consumption. In addition, it is imperative that attention is paid to the product development and manufacturing process, and that safety and quality properties are monitored. Importantly, the beneficial effects of probiotics should be evaluated in product efficacy studies and post-marketing surveys in order to demonstrate their clinical efficacy. All these aspects need to be evaluated and validated during the development of a successful high-quality and ready-to-market probiotic.

Cranberry Polyphenols and Prevention against Urinary Tract Infections: Relevant Considerations

Cranberry (Vaccinium macrocarpon) is a distinctive source of polyphenols as flavonoids and phenolic acids that has been described to display beneficial effects against urinary tract infections (UTIs), the second most common type of infections worldwide. UTIs can lead to significant morbidity, especially in healthy females due to high rates of recurrence and antibiotic resistance. Strategies and therapeutic alternatives to antibiotics for prophylaxis and treatment against UTIs are continuously being sought after. Different to cranberry, which have been widely recommended in traditional medicine for UTIs prophylaxis, probiotics have emerged as a new alternative to the use of antibiotics against these infections and are the subject of new research in this area. Besides uropathogenic Escherichia coli (UPEC), the most common bacteria causing uncomplicated UTIs, other etiological agents, such as Klebsiellapneumoniae or Gram-positive bacteria of Enterococcus and Staphylococcus genera, seem to be more widespread than previously appreciated. Considerable current effort is also devoted to the still-unraveled mechanisms that are behind the UTI-protective effects of cranberry, probiotics and their new combined formulations. All these current topics in the understanding of the protective effects of cranberry against UTIs are reviewed in this paper. Further progresses expected in the coming years in these fields are also discussed.

Efficacy of Probiotic Prophylaxis After The First Febrile Urinary Tract Infection in Children With Normal Urinary Tracts

BACKGROUND

Growing antibiotic resistance and debates over their efficacy for urinary tract infection (UTI) recurrence warrants studying nonantibiotic prophylaxis for preventing UTI recurrences.

METHODS

We randomly assigned 181 children, aged 4 months to 5 years, with a normal urinary tract after recovery from their first febrile UTI in a 1:1 ratio to receive a probiotic mixture of Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, and Bifidobacterium lactis (n = 91) or placebo (n = 90) for a total of 18 months of therapy. The primary objective was to show the superiority of probiotic prophylaxis to placebo. The primary end point was composite cure (UTI-free survival) at 18 months, and the secondary end point was the median time to first UTI recurrence.

RESULTS

The probiotics were superior to placebo with respect to the primary efficacy end point. At 18 months, composite cure was observed in 96.7% (3 of 91) of the patients in the probiotic group and 83.3% (15 of 90) of those in the placebo group (P = .02). The median time to the first incidence of UTI recurrence was 3.5 months (range, 1-4 months) and 6.5 months (range, 2-14 months) in the probiotic and placebo groups, respectively (P = .04). The main microorganism that caused recurrent UTI was Escherichia coli, followed by Klebsiella pneumoniae, and these results were not significantly different between the 2 groups. We found no specific adverse events among the participants who received the probiotic mixture during the course of therapy.

CONCLUSIONS

The probiotics were more effective than placebo at reducing the risk of recurrent UTI in children with a normal urinary tract after their first episode of febrile UTI.

Complete Genome of Lactobacillus iners KY Using Flongle Provides Insight Into the Genetic Background of Optimal Adaption to Vaginal Econiche

Despite the importance of Lactobacillus iners and its unique characteristics for the study of vaginal adaption, its genome and genomic researches for identifying molecular backgrounds of these specific phenotypes are still limited. In this study, the first complete genome of L. iners was constructed using a cost-effective long-read sequencing platform, Flongle from Oxford Nanopore, and comparative genome analysis was conducted using a total of 1,046 strain genomes from 10 vaginal Lactobacillus species. Single-molecule sequencing using Flongle effectively resolved the limitation of the 2nd generation sequencing technologies in dealing with genomic regions of high GC contents, and comparative genome analysis identified three potential core genes (INY, ZnuA, and hsdR) of L. iners which was related to its specific adaption to the vaginal environment. In addition, we performed comparative prophage analysis for 1,046 strain genomes to further identify the species specificity. The number of prophages in L. iners genomes was significantly smaller than other vaginal Lactobacillus species, and one of the specific genes (hsdR) was suggested as the means for defense against bacteriophage. The first complete genome of L. iners and the three specific genes identified in this study will provide useful resources to further expand our knowledge of L. iners and its specific adaption to the vaginal econiche.

Fertility factors affect the vaginal microbiome in women of reproductive age

Problem

For women of reproductive age, achieving a successful pregnancy requires both the normal functioning of reproductive endocrine and the health of the reproductive tract environment. We aimed to study how these fertility factors, such as female age, baseline sexual hormone levels, tubal patency, and vaginal pH, affect the composition of vaginal microbiome.

Method of study

The 16S rRNA sequencing was carried on vaginal microbiome samples from 85 women of reproductive age without vaginal infections or reproductive endocrine diseases. The detailed correlations between fertility factors and vaginal microbiome were quantified by Spearman's rank tests. A linear discriminant analysis was carried out to explore the effects of fertility factors on the relative abundances of vaginal bacterial species.

Results

The vaginal pH, levels of basal E2, LH, and FSH all had significant effects on the distribution of vaginal microbiome. The relative abundances of vaginal bacterial species, including Escherichia coli, Streptococcus agalactiae, and Prevotella intermedia, were significantly different due to the host's state of reproductive endocrine and tubal patency. It was worth noting that women with tubal obstruction, or prolonged menstrual cycle, or antral follicle count >15, or vaginal pH > 4.5 all had a higher abundance of Escherichia coli in vagina.

Conclusion

The fertility factors associated with the reproductive endocrine and the genital tract environment affected vaginal microbiome in women of reproductive age. The species Escherichia coli, Streptococcus agalactiae, Prevotella intermedia, etc could be used as biomarkers to reflect the pathological state of reproductive endocrine and genital tract.

Nonantibiotic prevention and management of recurrent urinary tract infection

Urinary tract infections (UTIs) are highly prevalent, lead to considerable patient morbidity, incur large financial costs to health-care systems and are one of the most common reasons for antibiotic use worldwide. The growing problem of antimicrobial resistance means that the search for nonantibiotic alternatives for the treatment and prevention of UTI is of critical importance. Potential nonantibiotic measures and treatments for UTIs include behavioural changes, dietary supplementation (such as Chinese herbal medicines and cranberry products), NSAIDs, probiotics, D-mannose, methenamine hippurate, estrogens, intravesical glycosaminoglycans, immunostimulants, vaccines and inoculation with less-pathogenic bacteria. Some of the results of trials of these approaches are promising; however, high-level evidence is required before firm recommendations for their use can be made. A combination of these agents might provide the optimal treatment to reduce recurrent UTI, and trials in specific population groups are required.

Modifications in Vaginal Microbiota and Their Influence on Drug Release: Challenges and Opportunities

Vaginal drug delivery represents an attractive alternative to achieve local and systemic effects due to the high contact surface exposed, the mucoadhesion of the epithelium, and the high innervation that facilitates the absorption of drugs into the bloodstream. However, despite the confinement of the vaginal cavity, it is an organ with a highly variable microenvironment. Mechanical alterations such as coitus, or chemical changes such as pH and viscosity, modify the release of drugs. In addition, changes in vaginal microbiota can influence the entire vaginal microenvironment, thus determining the disposition of drugs in the vaginal cavity and decreasing their therapeutic efficacy. Therefore, the influence of microorganisms on vaginal homeostasis can change the pre-established scenario for the application of drugs. This review aims to provide an explanation of normal vaginal microbiota, the factors that modify it, its involvement in the administration of drugs, and new proposals for the design of novel pharmaceutical dosage forms. Finally, challenges and opportunities directed toward the conception of new effective formulations are discussed.

Reassessment of Routine Midstream Culture in Diagnosis of Urinary Tract Infection

Midstream urine (MSU) culture remains the gold standard diagnostic test for confirming urinary tract infection (UTI). We previously showed that patients with chronic lower urinary tract symptoms (LUTS) below the diagnostic cutoff on MSU culture may still harbor bacterial infection and that their antibiotic treatment was associated with symptom resolution. Here, we evaluated the results of the United Kingdom's MSU culture in symptomatic patients and controls. Next, we compared the bacterial enrichment capabilities of the MSU culture with those of a 50-µl uncentrifuged culture, a 30-ml centrifuged sediment culture, and 16S rRNA gene sequencing. This study was conducted on urine specimens from 33 LUTS patients attending their first clinical appointment (mean age, 48.7 years; standard deviation [SD], 16.5 years), 30 LUTS patients on treatment (mean age, 47.8 years; SD, 16.5 years) whose symptoms had relapsed, and 29 asymptomatic controls (mean age, 40.7 years, SD, 15.7 years). We showed that the routine MSU culture, adopting the UK interpretation criteria tailored to acute UTI, failed to detect a variety of bacterial species, including recognized uropathogens. Moreover, the diagnostic MSU culture was unable to discriminate between patients and controls. In contrast, genomic analysis of urine enriched by centrifugation discriminated between the groups, generating a more accurate understanding of species richness. In conclusion, the United Kingdom's MSU protocol misses a significant proportion of bacteria, which include recognized uropathogens, and may be unsuitable for excluding UTI in patients with LUTS.

Diversity of vaginal microbiota in sub-Saharan Africa and its effects on HIV transmission and prevention

The vaginal microbial community ("microbiota") is a key component of the reproductive health of women, providing protection against urogenital infections. In sub-Saharan Africa, there is a high prevalence of bacterial vaginosis, a condition defined by bacterial overgrowth and a shift away from a Lactobacillus-dominated profile toward increased percentages of strict anaerobic species. Bacterial vaginosis is associated with an increased risk of HIV acquisition and transmission, as well as an increased risk of acquiring other sexually transmitted infections, preterm births, and pelvic inflammatory disease. Vaginal microbiota, rich in taxa of strict anaerobic species, disrupts the mucosal epithelial barrier through secretion of metabolites and enzymes that mediate inflammation. Advancements in next-generation sequencing technologies such as whole-genome sequencing have led to deeper profiling of the vaginal microbiome and further study of its potential role in HIV pathogenesis and treatment. Until recently data on the composition of the vaginal microbiome in sub-Saharan Africa have been limited; however, a number of studies have been published that highlight the critical role of vaginal microbiota in disease and health in African women. This article reviews these recent findings and identifies gaps in knowledge about variations in female genital commensal bacteria that could provide vital information to improve the effectiveness of interventions to prevent HIV and other sexually transmitted infections. In addition, we review the effects of pregnancy, contraception, and sexual practices on vaginal microbiome and the potential of vaginal microbiota on HIV transmission and prevention. A better understanding of the role of vaginal microbiota in host susceptibility to HIV infection and its prevention among African women could inform the development of novel local and systemic interventions to minimize new HIV infections among high-risk women.

Lactobacillus crispatus BC5 Interferes With Chlamydia trachomatis Infectivity Through Integrin Modulation in Cervical Cells

Lactobacilli play a crucial role in maintaining the ecological equilibrium of the vaginal niche, preventing the colonization of exogenous microorganisms. Although many studies have discussed the mechanisms displayed by lactobacilli in counteracting several urogenital pathogens, a few data are available on the interaction between lactobacilli and Chlamydia trachomatis. This study aimed to elucidate the molecular bases of the interaction among vaginal lactobacilli, the sexually transmitted pathogen C. trachomatis and the epithelial cervical cells. We evaluated the in vitro activity of 15 Lactobacillus strains, belonging to different species (i.e., L. crispatus, L. gasseri, L. vaginalis), against C. trachomatis. In particular, we evaluated the capability of lactobacilli cells to interfere with C. trachomatis infection in HeLa cells, by exclusion assays. Lactobacilli significantly reduced C. trachomatis infectivity, being L. crispatus the most active species. Although a dose-dependent effect was noticed, a significant antagonistic activity was maintained even at lower doses. As other Gram-positive bacteria (i.e., Streptococcus agalactiae, Enterococcus faecalis, and Bacillus subtilis) failed to interfere with C. trachomatis infectivity, Lactobacillus activity proved to be specific. The potential mechanism of protection was investigated in Lactobacillus crispatus BC5, chosen as the model strain. The incubation of HeLa cell line with BC5 cells induced important modifications in the epithelial plasma membrane, by altering lipid composition and α5 integrin subunit exposure. When α5 integrin subunits were masked by a specific blocking antibody or ITGA5 gene expression was silenced, Chlamydia infection was significantly reduced. It follows that α5 integrin subunit is crucial for the pathogen infection process, and the anti-Chlamydia activity can be directly linked to membrane properties modifications in cervical cells. The three Gram-positive bacteria used as controls failed to modify the expression of α5β1 integrin. In conclusion, we identified a potential molecular mechanism at the basis of the protection exerted by L. crispatus BC5 against C. trachomatis, getting insights into the role of the cervico-vaginal microbiota for the woman’s health.

Managing recurrent urinary tract infections in kidney transplant patients

INTRODUCTION

Recurrent urinary tract infections (UTI) are a common clinical problem in kidney transplant recipients. Due to the complex urological anatomy derived from the implantation of the kidney graft, the spectrum of the disease and the broad underlying pathophysiological mechanisms. Recurrent UTI worsen the quality of life, decrease the graft survival and increase the costs of kidney transplantation. Areas covered: In this review, we describe the definitions, clinical characteristics, pathophysiological mechanisms and microbiology of recurrent urinary tract infections in kidney transplantations. The actual published literature on the management of recurrent urinary tract infections is based on case series, observational cohorts and very few clinical trials. In this review, the available evidence is compiled to propose evidence-based strategies to manage these complex cases. Expert commentary: The management of recurrent urinary tract infections in kidney transplant patients requires a proper diagnosis of the underlying mechanism. Early identification of structural or functional urological abnormalities, potentially amenable for surgical correction, is crucial for a successful management. The use of antibiotics to prevent recurrent infections should be carefully evaluated to avoid side effects and emergence of antibiotic-resistant microorganisms.

Lactobacillus rhamnosus GG prevents epithelial barrier dysfunction induced by interferon-gamma and fecal supernatants from irritable bowel syndrome patients in human intestinal enteroids and colonoids

Disruption of intestinal barrier homeostasis is an important pathogenic factor in conditions such as irritable bowel syndrome (IBS). Lactobacillus rhamnosus GG (LGG) improves IBS symptoms through unclear mechanisms. Previous studies utilizing colorectal adenocarcinoma cell lines showed that LGG metabolites prevented interferon gamma (IFN-gamma) induced barrier damage but the model employed limited these findings. We aimed to interrogate the protective effects of LGG on epithelial barrier function using human intestinal epithelial cultures (enteroids and colonoids) as a more physiologic model. To investigate how LGG affects epithelial barrier function, we measured FITC-Dextran (FD4) flux across the epithelium as well as tight junction zonula occludens 1 (ZO-1) and occludin (OCLN) expression. Colonoids were incubated with fecal supernatants from IBS patients (IBS-FSN) and healthy controls in the presence or absence of LGG to examine changes in gut permeability. Enteroids incubated with IFN-gamma demonstrated a downregulation of OCLN and ZO-1 expression by 67% and 50%, respectively (p<0.05). This was accompanied by increased paracellular permeability as shown by leakage of FD4. Pretreatment of enteroids with LGG prevented these changes and normalized OCLN and ZO-1 to control levels. These actions were independent of its action against apoptosis. However, these protective effects were not seen with LGG cell wall extracts, LGG DNA, or denatured (boiled) LGG. Intriguingly, IBS-FSN injected into colonoids increased paracellular permeability, which was prevented by LGG. LGG, likely due to secreted proteins, protects against epithelial barrier dysfunction. Bacterial-derived factors to modulate gut barrier function may be a treatment option in disorders such as IBS.

Recurrent urinary tract infections in women: How promising is the use of probiotics?

Urinary tract infections (UTIs) currently rank amongst the most prevalent bacterial infections, representing a major health hazard. UTIs in females usually start as vaginal infections and ascend to the urethra and bladder. Recurrent UTIs (rUTIs) can be defined as at least three episodes of UTI in 1 year or two episodes in 6 months. Various antibiotics have been the mainstay of therapy in ameliorating the incidence of UTIs, but recurrent infections continue to afflict many women. It necessitates the exploitation of alternative antimicrobial therapy. Probiotics have been shown to be effective in varied clinical trials for long-term preventions of rUTI. Because Escherichia coli is the primary pathogen involved in UTIs which spreads from the rectum to vagina and then ascends up the sterile urinary tract, improving the gut or vaginal flora will thus impact the urinary tract. Since a healthy vaginal microbiota is mainly dominated by Lactobacillus species, in this context, exogenously administered probiotics containing Lactobacilli play a pivotal role in reducing the risk of rUTI. The concept of artificially boosting the Lactobacilli numbers through probiotic administration has long been conceived but has been recently shown to be possible. Lactobacilli may especially be useful for women with a history of recurrent, complicated UTIs or on prolonged antibiotic use. Probiotics do not cause antibiotic resistance and may offer other health benefits due to vaginal re-colonisation with Lactobacilli. However, more comprehensive research is still needed, to recommend for probiotics as an alternative to antibiotics.

Bioengineered intravaginal isolate of Lactobacillus plantarum expresses algal lectin scytovirin demonstrating anti-HIV-1 activity

Efforts to develop preventatives against HIV infection through sexual route have identified, among many, algal lectins as the potent molecules for scaffolding HIV entry inhibition. Algal lectin scytovirin (SVN) from Scytonema varium, a cyanobacterium, has anti-HIV effects with the potential for use in sculpting HIV neutralization. We created a recombinant strain of human vaginal L. plantarum for extracellular expression of recombinant (r)SVN. The rSVN protein containing culture supernatant was analyzed for its binding with HIV-1 gp160, and for inhibiting infection with primary R5 and X4 HIV-1 strains in TZM-bl cells. The rSVN protein extant in recombinant L. plantarum culture supernatant binds to HIV-1 gp160 and reduces the HIV-induced cytopathic effect to nearly 56.67% and 86.47% in R5 and X4 HIV-1 infected TZM-bl cells, respectively. The fortified L. plantarum may be explored for its use as a live virucide in vaginal mucosa of high risk women to prevent HIV entry.

Parallel detection of lactobacillus and bacterial vaginosis-associated bacterial DNA in the chorioamnion and vagina of pregnant women at term

BACKGROUND

The majority of early preterm births are associated with intrauterine infections, which are thought to occur when microbes traffic into the uterus from the lower genital tract and seed the placenta. Bacterial vaginosis (BV) is associated with heterogeneous bacterial communities in the vagina and is linked to preterm birth. The extent to which trafficking into the uterus of normal and BV-associated vaginal bacteria occurs is unknown. The study objective was to characterize in parallel the distribution and quantities of bacteria in the vagina, uterus, and placental compartments.

METHODS

Pregnant women at term (≥37 weeks) presenting for delivery were recruited prospectively. Swabs were collected in parallel from the vagina, chorioamnion. Choriodecidual swabs were collected if a cesarean section was performed. Samples were analyzed by culture, broad-range 16S rRNA gene PCR, and bacterial species-specific quantitative PCR (qPCR) for DNA from Lactobacillus and a panel of BV-associated bacteria. Results were correlated with placental histopathology.

RESULTS

Of the 23 women enrolled, 15 were delivered by cesarean section (N = 10 without labor; N = 5 in labor) and eight were delivered vaginally. BV was diagnosed in two women not in labor. Placental histopathology identified chorioamnionitis or funisitis in six cases [1/10 (10%) not in labor; 5/13 (38%) in labor]. Among non-laboring women, broad-range 16S qPCR detected bacteria in the chorioamnion and the choriodecidua (4/10; 40%). Among laboring women, Lactobacillus species were frequently detected in the chorioamnion by qPCR (4/13; 31%). In one case, mild chorioamnionitis was associated with qPCR detection of similar microbes in the chorioamnion and vagina (e.g. Leptotrichia/Sneathia, Megasphaera), along a quantitative gradient.

CONCLUSIONS

Microbial trafficking of lactobacilli and fastidious bacteria into the chorioamniotic membranes and choriodecidua occurs at term in normal pregnancies. In one case, we demonstrated a quantitative gradient between multiple bacterial species in the lower genital tract and placenta. Not all bacterial colonization is associated with placental inflammation and clinical sequelae. Further studies of the role of placental colonization with Lactobacillus in normal pregnancy and fastidious bacteria in chorioamnionitis may improve prevention and treatment approaches for preterm labor.

Strain-specific inhibition of the adherence of uropathogenic bacteria to bladder cells by probiotic Lactobacillus spp

Urinary tract infections (UTIs), one of most common infections worldwide, face high recurrence rates and increasing antimicrobial resistance. Probiotic bacteria, especially of the genus Lactobacillus, are considered a promising preventive and/or treatment therapy against UTIs. In order to elucidate the mechanisms involved in these beneficial effects, we studied the impact of different Lactobacillus strains (Lactobacillus salivarius UCM572, L. plantarum CLC17 and L. acidophilus 01) in the adherence of reference and clinical uropathogenic strains (Escherichia coli ATCC® 53503, E. coli 10791, Enterococcus faecalis 04-1, En. faecalis 08-1 and Staphylococcus epidermidis 08-3) to T24 epithelial bladder cells. In general, the Lactobacillus strains with previous in vivo evidence of beneficial effects against UTIs (L. salivarius UCM572 and L. acidophilus 01) significantly inhibited the adherence of the five uropathogens to T24 cells, displaying percentages of inhibition ranging between 22.2% and 43.9%, and between 16.5% and 53.7%, respectively. On the other hand, L. plantarum CLC17, a strain with no expected effects on UTIs, showed almost negligible anti-adherence effects.Therefore, these in vitro results suggest that inhibition of the adherence of uropathogens to epithelial bladder cells may be one of the mechanisms involved in the potential beneficial effects of probiotics against UTIs in vivo.

Women and Their Microbes: The Unexpected Friendship

Communities of microbiota have been associated with numerous health outcomes, and while much emphasis has been placed on the gastrointestinal niche, there is growing interest in the microbiome specific for female reproductive health and the health of their offspring. The vaginal microbiome plays an essential role not only in health and dysbiosis, but also potentially in successful fertilization and healthy pregnancies. In addition, microbial communities have been isolated from formerly forbidden sterile niches such as the placenta, breast, uterus, and Fallopian tubes, strongly suggesting an additional microbial role in women's health. A combination of maternally linked prenatal, birth, and postnatal factors, together with environmental and medical interventions, influence early and later life through the microbiome. Here, we review the role of microbes in female health focusing on the vaginal tract and discuss how male and female reproductive microbiomes are intertwined with conception and how mother-child microbial transfer is a key determinant in infant health, and thus the next generation.

The Vaginal Microbiota and Urinary Tract Infection

The vagina is a key anatomical site in the pathogenesis of urinary tract infection (UTI) in women, serving as a potential reservoir for infecting bacteria and a site at which interventions may decrease the risk of UTI. The vaginal microbiota is a dynamic and often critical factor in this pathogenic interplay, because changes in the characteristics of the vaginal microbiota resulting in the loss of normally protective Lactobacillus spp. increase the risk of UTI. These alterations may result from the influence of estrogen deficiency, antimicrobial therapy, contraceptives, or other causes. Interventions to reduce adverse effects on the vaginal microbiota and/or to restore protective lactobacilli may reduce the risks of UTI.

Interaction of vaginal Lactobacillus strains with HeLa cells plasma membrane

Vaginal lactobacilli offer protection against recurrent urinary and vaginal infections. The precise mechanisms underlying the interaction between lactobacilli and the host epithelium remain poorly understood at the molecular level. Deciphering such events can provide valuable information on the mode of action of commensal and probiotic bacteria in the vaginal environment. We investigated the effects exerted by five Lactobacillus strains of vaginal origin (Lactobacillus crispatus BC1 and BC2, Lactobacillus gasseri BC9 and BC11 and Lactobacillus vaginalis BC15) on the physical properties of the plasma membrane in a cervical cell line (HeLa). The interaction of the vaginal lactobacilli with the cervical cells determined two kinds of effects on plasma membrane: (1) modification of the membrane polar lipid organisation and the physical properties (L. crispatus BC1 and L. gasseri BC9); (2) modification of α5β1 integrin organisation (L. crispatus BC2, L. gasseri BC11 and L. vaginalis BC15). These two mechanisms can be at the basis of the protective role of lactobacilli against Candida albicans adhesion. Upon stimulation with all Lactobacillus strains, we observed a reduction of the basal oxidative stress in HeLa cells that could be related to modifications in physical properties and organisation of the plasma membrane. These results confirm the strictly strain-specific peculiarities of Lactobacillus and deepen the understanding of the mechanisms underlying the health-promoting role of this genus within the vaginal ecosystem.

Is the role of human female reproductive tract microbiota underestimated?

An issue that is currently undergoing extensive study is the influence of human vaginal microbiota (VMB) on the health status of women and their neonates. Healthy women are mainly colonised with lactobacilli such as Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus iners; however, other bacteria may be elements of the VMB, particularly in women with bacterial vaginosis. The implementation of culture-independent molecular methods in VMB characterisation, especially next-generation sequencing, have provided new information regarding bacterial diversity in the vagina, revealing a large number of novel, fastidious, and/or uncultivated bacterial species. These molecular studies have contributed new insights regarding the role of bacterial community composition. In this study, we discuss recent findings regarding the reproductive tract microbiome. Not only bacteria but also viruses and fungi constitute important components of the reproductive tract microbiome. We focus on aspects related to the impact of the maternal microbiome on foetal development, as well as the establishment of the neonatal microbiomes, including the placenta microbiome, and the haematogenous source of intrauterine infection. We also discuss whether the role of the vaginal microbiome is currently understood and appreciated.

Lactobacillus crispatus Modulates Vaginal Epithelial Cell Innate Response to Candida albicans

BACKGROUND

Vulvovaginal candidiasis is caused by Candida albicans. The vaginal epithelium, as the first site of the initial stage of infection by pathogens, plays an important role in resisting genital tract infections. Moreover, lactobacilli are predominant members of the vaginal microbiota that help to maintain a normal vaginal microenvironment. Therefore, Lactobacillus crispatus was explored for its capacity to intervene in the immune response of vaginal epithelial cells VK2/E6E7 to C. albicans.

METHODS

We examined the interleukin-2 (IL-2), 4, 6, 8, and 17 produced by VK2/E6E7 cells infected with C. albicans and treated with L. crispatus in vitro. The capacity of L. crispatus to adhere to VK2/E6E7 and inhibit C. albicans growth was also tested by scanning electron microscopy (SEM) and adhesion experiments.

RESULTS

Compared with group VK2/E6E7 with C. albicans, when treated with L. crispatus, the adhesion of C. albicans to VK2/E6E7 cells decreased significantly by 52.87 ± 1.22%, 47.03 ± 1.35%, and 42.20 ± 1.55% under competition, exclusion, and displacement conditions, respectively. SEM revealed that the invasion of C. albicans into VK2/E6E7 cells was caused by induced endocytosis and active penetration. L. crispatus could effectively protect the cells from the virulence of hyphae and spores of C. albicans and enhance the local immune function of the VK2/E6E7 cells. The concentrations of IL-2, 6, and 17 were upregulated significantly (P < 0.01) and that of IL-8 were downregulated significantly (P < 0.01) in infected VK2/E6E7 cells treated with L. crispatus. The concentration of IL-4 was similar to that of the group VK2/E6E7 with C. albicans (24.10 ± 0.97 vs. 23.12 ± 0.76 pg/ml, P = 0.221).

CONCLUSIONS

L. crispatus can attenuate the virulence of C. albicans, modulate the secretion of cytokines and chemokines, and enhance the immune response of VK2/E6E7 cells in vitro. The vaginal mucosa has a potential function in the local immune responses against pathogens that can be promoted by L. crispatus.

Bacteria Interfere with A. actinomycetemcomitans Colonization

It is known that beneficial bacteria can suppress the emergence of pathogenic bacteria, particularly in the gastrointestinal tract. This study examined the potential for a similar suppression of Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans colonization of epithelial cells, due to its potential relevance in periodontal diseases. Seven presumed beneficial bacteria were examined for their ability to interfere, exclude, or displace A. actinomycetemcomitans from epithelial cells in vitro. Streptococcus sanguinis, Streptococcus mitis, and Streptococcus salivarius showed prominent inhibitory effects on either A. actinomycetemcomitans recovery or colonization. These results confirmed the hypothesis that bacterial interactions interfere with A. actinomycetemcomitans colonization of epithelial cells in vitro, and demonstrated the potential beneficial effects of S. mitis, S. salivarius, and S. sanguinis.