Selection of Lactobacillus strains as potential probiotics for vaginitis treatment

Beyond hormones: 3PM approach to vaginal microbiota dynamics in postmenopausal women

Menopause marks a critical transition characterized by ceased ovarian function and declining estrogen levels, affecting multiple systems with vasomotor symptoms and genitourinary syndrome of menopause (GSM). Recent evidence shows vaginal microbiota undergoes significant alterations during menopause, influencing GSM severity. This comprehensive review examined vaginal microbiota dynamics in postmenopausal women through Predictive, Preventive, and Personalized Medicine (3PM/PPPM), revealing characteristic shifts-increased alpha diversity, reduced Lactobacillus dominance, and transitions toward non-Lactobacillus species-that serve as potential predictive biomarkers for the menopausal state, premature ovarian insufficiency, and GSM symptoms. The analysis evaluated microbiota-based risk stratification strategies for vaginal dysbiosis and demonstrated the effectiveness of both hormonal interventions (systemic/local estrogen, tibolone, ospemifene) and non-hormonal alternatives (probiotics, energy-based devices, pessary) in normalizing microbiota composition and improving vaginal health. The application of PPPM/3PM transformed menopausal healthcare from reactive to proactive precision-based care by establishing microbiota-based biomarkers that predict health risks, enable early targeted interventions tailored to specific microbiota profiles, and guide personalized treatment approaches based on individual microbial compositions. While this paradigm shift significantly advances gynecological medicine, research gaps remain in validating baseline microbiota signatures as predictive biomarkers and establishing standardized screening protocols. Further studies are needed to validate interventions such as probiotics and prebiotics, optimizing strain selection for personalized, evidence-based preventive and therapeutic strategies. Developing standardized yet personalized protocols to restore a balanced vaginal microbiome could help alleviate menopause-related symptoms. Advancing microbiota-based personalized therapeutic approaches is crucial to enhancing the quality of life for postmenopausal women through targeted and individualized vaginal health management.

The role of reproductive tract microbiota in gynecological health and diseases

The reproductive tract, as a lumen connected to the outside world, its microbial community is influenced by various factors. The changes in its microbiome are closely related to women's health. The destruction of the micro ecological environment will lead to various infections, such as Bacterial vaginosis, sexually transmitted infections, adverse pregnancy outcomes, infertility and tumors. In recent years, with the continuous development and progress of molecular biology, research on reproductive tract microbiota has become a clinical hotspot. The reproductive tract microbiota is closely related to the occurrence and development of female reproductive tract diseases such as vaginitis, pelvic inflammation, PCOS, cervical lesions, and malignant tumors. This article reviews the research on the relationship between vaginal microbiota and female reproductive tract diseases, in order to provide theoretical basis for the prevention and treatment of female reproductive tract diseases.

Chronic endometritis and fertility: A binomial linked by microorganisms

OBJECTIVES

To explore the relationship of microorganisms with chronic endometritis, comparing findings in our region with reports in the literature.

STUDY DESIGN

Retrospective descriptive study of 110 endometrial biopsies from women treated for fertility problems at a tertiary hospital from 2021 through 2022. Results were compared between women with and without chronic endometritis.

RESULTS

Chronic endometritis was diagnosed in 50.91 % (n = 56) of the women, with at least one microorganism detected in 57.14 % (n = 32). Microorganisms other than Lactobacillus spp. were more often (p = 0.009) observed in women with chronic endometritis. The most frequently isolated non-Lactobacillus microorganism was Gardnerella vaginalis (10.71 %), followed by Streptococcus anginosus (8.93 %), S. agalactiae (5.36 %), and Corynebacterium amycolatum (5.36 %). There was a trend towards a lower frequency of Lactobacillus spp. in women with chronic endometritis (p = 0.08672).

CONCLUSIONS

The endometrial microbiota significantly differs between women with versus without chronic endometritis, observing a reduced proportion of Lactobacillus spp. and proteobacteria and an increased proportion of Gardnerella spp. in the former. However, further research is needed on the relationship between microorganisms and chronic endometritis to assist therapeutic decision-making and improve the reproductive prognosis.

Aggregation and adhesion ability of various probiotic strains and Candida species: An in vitro study

Background/purpose

The ability of probiotics to inhibit Candida adhesion is a crucial characteristic that prevents Candida colonization and infection progression. This study aimed to explore aggregation, adhesion, and cell surface characterization of probiotic and Candida strains and to evaluate the effect of probiotics and their cell-free supernatants (CFSs) as postbiotics on Candida adhesion to human oral keratinocytes.

Materials and methods

Eight probiotic strains and five reference Candida strains were tested for autoaggregation, coaggregation, adhesin on human oral keratinocytes (H357), and cell surface properties. The anti-Candida adhesion activities of probiotic strains and CFSs were investigated.

Results

The results showed that most probiotics exhibited high adhesion to H357 cells, specifically oral probiotic Lacticaseibacillus rhamnosus SD4, Limosilactobacillus fermentum SD7, and L. rhamnosus SD11, and adhesion ability of probiotic strains was strongly related to their autoaggregation, cell surface charges, and hydrophobicity. Candida strains also revealed a high level of adhesion to H357 cells. Candida albicans and C andida glabrata showed significantly higher adhesion abilities than others. After a combination of Candida with probiotics or their CFSs, Candida adhesion was significantly reduced. The anti-Candida adhesion property of probiotics was strongly related to their autoaggregation, coaggregation, and adhesion abilities.

Conclusion

This study demonstrated that oral probiotic strains may be useful probiotics for preventing and treating oral candidiasis due to their high ability of aggregation, adhesion, and anti-Candida adhesion to H357 cells.

Characterization of Vaginal Lactobacilli with Potential Probiotic Properties Isolated from Healthy Women in Northern Iran

Vaginal lactobacilli protect against bacterial vaginosis and vaginal candidiasis. They may have probiotic properties and help maintain the balance and health of the vaginal ecosystem while the loss of these bacteria predisposes females to urinary and genital infections. The aim of this study was to investigate the probiotic potential of vaginal Lactobacillus among healthy females in northern Iran. The Lactobacillus strains were isolated from vaginal samples and were identified by sequencing of the 16S rRNA fragment. Functional properties such as tolerance to low pH, H2O2 production, adherence ability to Hela cells and antagonistic activity against Candida albicans was examined. A total of 38 vaginal lactobacilli strains from five species, including Lactobacillus crispatus (n = 13), Lactobacillus gasseri (n = 10), Lactobacillus acidophilus (n = 6), Lactobacillus jensenii (n = 5) and Lactobacillus johnsonii (n = 4), were identified. All of the species showed significant tolerance to low pH over 24 h (p < 0.001). The best adherence ability to Hela cells was seen in Lactobacillus gasseri strains. Nearly 17 of the strains had higher anti-candida activity compared to the other strains. According to the findings, four lactobacilli strains isolated in the vaginal samples of healthy Iranian women had the best probiotic potential.

Candidiasis in Pregnancy: Relevant Aspects of the Pathology for the Mother and the Fetus and Therapeutic Strategies

Vulvovaginal candidiasis (VVC) is a common condition that can lead to significant discomfort, affecting approximately 70-75% of women at least once in their lives. During pregnancy, the prevalence of VVC is estimated to be around 20%, peaking at about 30% in the third trimester, with a number of specific risk factors predisposing to yeast infection being identified and needing elucidation. This review aims to provide updated knowledge on candidiasis during pregnancy, addressing risk factors and maternal and neonatal outcomes, as well as discussing optimal therapeutic strategies to safeguard mothers and newborns. The bibliographic search involved two biomedical databases, PubMed and Embase, without imposing time limits. Among all Candida spp., Candida albicans remains the most frequent causative species. The hyperestrogenic environment of the vaginal mucosa and reduced immune defenses, physiological effects of pregnancy, create conditions favorable for Candida spp. vaginal colonization and hence VVC. Recent evidence shows an association between VVC and adverse obstetric outcomes, including premature membrane rupture (PROM), chorioamnionitis, preterm birth, and puerperal infections. Prompt and effective management of this condition is therefore crucial to prevent adverse obstetric outcomes, maternal-fetal transmission, and neonatal disease. Additional studies are required to confirm the benefits of systemic treatment for maternal candida infection or colonization in preventing premature birth or neonatal systemic candidiasis.

The Anti-Inflammatory and Curative Exponent of Probiotics: A Comprehensive and Authentic Ingredient for the Sustained Functioning of Major Human Organs

Several billion microorganisms reside in the gastrointestinal lumen, including viruses, bacteria, fungi, and yeast. Among them, probiotics were primarily used to cure digestive disorders such as intestinal infections and diarrhea; however, with a paradigm shift towards alleviating health through food, their importance is large. Moreover, recent studies have changed the perspective that probiotics prevent numerous ailments in the major organs. Probiotics primarily produce biologically active compounds targeting discommodious pathogens. This review demonstrates the implications of using probiotics from different genres to prevent and alleviate ailments in the primary human organs. The findings reveal that probiotics immediately activate anti-inflammatory mechanisms by producing anti-inflammatory cytokines such as interleukin (IL)-4, IL-10, IL-11, and IL-13, and hindering pro-inflammatory cytokines such as IL-1, IL-6, and TNF-α by involving regulatory T cells (Tregs) and T helper cells (Th cells). Several strains of Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus reuteri, Bifidobacterium longum, and Bifidobacterium breve have been listed among the probiotics that are excellent in alleviating various simple to complex ailments. Therefore, the importance of probiotics necessitates robust research to unveil the implications of probiotics, including the potency of strains, the optimal dosages, the combination of probiotics, their habitat in the host, the host response, and other pertinent factors.

Bacteria-based drug delivery for treating non-oncological diseases

Bacteria inhabit all over the human body, especially the skin, gastrointestinal tract, respiratory tract, urogenital tract, as well as specific lesion sites, such as wound and tumor. By leveraging their distinctive attributes including rapid proliferation, inherent abilities to colonize various biointerfaces in vivo and produce diverse biomolecules, and the flexibility to be functionalized via genetic engineering or surface modification, bacteria have been widely developed as living therapeutic agents, showing promising potential to make a great impact on the exploration of advanced drug delivery systems. In this review, we present an overview of bacteria-based drug delivery and its applications in treating non-oncological diseases. We systematically summarize the physiological positions where living bacterial therapeutic agents can be delivered to, including the skin, gastrointestinal tract, respiratory tract, and female genital tract. We discuss the success of using bacteria-based drug delivery systems in the treatment of diseases that occur in specific locations, such as skin wound healing/infection, inflammatory bowel disease, respiratory diseases, and vaginitis. We also discuss the advantages as well as the limitations of these living therapeutics and bacteria-based drug delivery, highlighting the key points that need to be considered for further translation. This review article may provide unique insights for designing next-generation bacteria-based therapeutics and developing advanced drug delivery systems.

Management of diabetic foot ulcers using topical probiotics in a soybean-based concentrate: a multicentre study

OBJECTIVE

Diabetic foot ulcer (DFU) is a common complication in people with diabetes. Standard management includes strict glycaemic management, control of the infection, revascularisation, debridement, mechanical offloading and foot care education. This study aimed to evaluate the efficacy of using topical probiotics in a soybean-based concentrate in the management of DFUs.

METHOD

A retrospective, multicentre evaluation of patients with diabetes with non-infected DFUs between October 2020 and October 2021, and who were treated with twice daily topical application of probiotics in a soybean-based concentrate as an adjunct to standard wound care.

RESULTS

A total of 22 patients were enrolled into this study, including 16 males and six females, with a mean age of 61 years (range: 31-89 years). Defect size ranged from 1-33.5cm2 (mean: 7.2cm2). The mean number of days until complete healing was 51 (range: 21-112 days). Of the patients, 83% showed complete healing at the end of 16 weeks, 72% showed complete healing at 12 weeks, 56% at eight weeks, and 22% at four weeks. The wounds showed an average decrease in size of 0.59cm2 (9%) per week, calculated using generalised estimating equation.

CONCLUSION

This findings of this study provide a new perspective on the therapeutic potential of probiotics as an effective form of management in patients with small, hard-to-heal (chronic) DFUs.

The Potential Value of Probiotics after Dental Implant Placement

Dental implantation is currently the optimal solution for tooth loss. However, the health and stability of dental implants have emerged as global public health concerns. Dental implant placement, healing of the surgical site, osseointegration, stability of bone tissues, and prevention of peri-implant diseases are challenges faced in achieving the long-term health and stability of implants. These have been ongoing concerns in the field of oral implantation. Probiotics, as beneficial microorganisms, play a significant role in the body by inhibiting pathogens, promoting bone tissue homeostasis, and facilitating tissue regeneration, modulating immune-inflammatory levels. This review explores the potential of probiotics in addressing post-implantation challenges. We summarize the existing research regarding the importance of probiotics in managing dental implant health and advocate for further research into their potential applications.

A probiotic nanozyme hydrogel regulates vaginal microenvironment for Candida vaginitis therapy

Molecular therapeutics are limited for Candida vaginitis because they damage normal cells and tissues of vagina, aggravating the imbalance of vaginal microbiota and increasing the recurrence. To tackle this limitation, through the combination of peroxidase-like rGO@FeS₂ nanozymes [reduced graphene oxide (rGO)] with Lactobacillus-produced lactic acid and H₂O₂, a responsive hyaluronic acid (HA) hydrogel rGO@FeS₂/Lactobacillus@HA (FeLab) is developed. FeLab has simultaneous anti-Candida albicans and vaginal microbiota-modulating activities. In particular, the hydroxyl radical produced from rGO@FeS₂ nanozymes and Lactobacillus kills C. albicans isolated from clinical specimens without affecting Lactobacillus. In mice with Candida vaginitis, FeLab has obvious anti-C. albicans activity but hardly damages vaginal mucosa cells, which is beneficial to vaginal mucosa repair. Moreover, a higher proportion of Firmicutes (especially Lactobacillus) and a decrease in Proteobacteria reshape a healthy vaginal microbiota to reduce the recurrence. These results provide a combined therapeutic of nanozymes and probiotics with translational promise for Candida vaginitis therapy.

Bacterial-fungal interactions and their impact on microbial pathogenesis

Microbial communities of the human microbiota exhibit diverse effects on human health and disease. Microbial homeostasis is important for normal physiological functions and changes to the microbiota are associated with many human diseases including diabetes, cancer, and colitis. In addition, there are many microorganisms that are either commensal or acquired from environmental reservoirs that can cause diverse pathologies. Importantly, the balance between health and disease is intricately connected to how members of the microbiota interact and affect one another's growth and pathogenicity. However, the mechanisms that govern these interactions are only beginning to be understood. In this review, we outline bacterial-fungal interactions in the human body, including examining the mechanisms by which bacteria govern fungal growth and virulence, as well as how fungi regulate bacterial pathogenesis. We summarize advances in the understanding of chemical, physical, and protein-based interactions, and their role in exacerbating or impeding human disease. We focus on the three fungal species responsible for the majority of systemic fungal infections in humans: Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus. We conclude by summarizing recent studies that have mined microbes for novel antimicrobials and antivirulence factors, highlighting the potential of the human microbiota as a rich resource for small molecule discovery.

Corrected and Republished from: "Understanding Lactobacillus paracasei and Streptococcus oralis Biofilm Interactions through Agent-Based Modeling"

As common commensals residing on mucosal tissues, Lactobacillus species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other organisms in those environments. In this study we used a combination of in vitro imaging of live biofilms and computational modeling to explore biofilm interactions between Streptococcus oralis, an accessory pathogen in oral candidiasis, and Lactobacillus paracasei, an organism with known probiotic properties. A computational agent-based model was created where the two species interact only by competing for space, oxygen, and glucose. Quantification of bacterial growth in live biofilms indicated that S. oralis biomass and cell numbers were much lower than predicted by the model. Two subsequent models were then created to examine more complex interactions between these species, one where L. paracasei secretes a surfactant and another where L. paracasei secretes an inhibitor of S. oralis growth. We observed that the growth of S. oralis could be affected by both mechanisms. Further biofilm experiments support the hypothesis that L. paracasei may secrete an inhibitor of S. oralis growth, although they do not exclude that a surfactant could also be involved. This contribution shows how agent-based modeling and experiments can be used in synergy to address multiple-species biofilm interactions, with important roles in mucosal health and disease. IMPORTANCE We previously discovered a role of the oral commensal Streptococcus oralis as an accessory pathogen. S. oralis increases the virulence of Candida albicans infections in murine oral candidiasis and epithelial cell models through mechanisms which promote the formation of tissue-damaging biofilms. Lactobacillus species have known inhibitory effects on biofilm formation of many microbes, including Streptococcus species. Agent-based modeling has great advantages as a means of exploring multifaceted relationships between organisms in complex environments such as biofilms. Here, we used an iterative collaborative process between experimentation and modeling to reveal aspects of the mostly unexplored relationship between S. oralis and L. paracasei in biofilm growth. The inhibitory nature of L. paracasei on S. oralis in biofilms may be exploited as a means of preventing or alleviating mucosal fungal infections.

Antimicrobial and immunoregulatory effects of Lactobacillus delbrueckii 45E against genitourinary pathogens

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Lactobacillus helveticus HY7801 ameliorates bacterial vaginosis by inhibiting biofilm formation and epithelial cell adhesion of Gardnerella vaginalis

Bacterial vaginosis (BV) is caused by a microbial imbalance in the vaginal ecosystem, which causes genital discomfort and a variety of potential complications in women. This study validated the potential of Lactobacillus helveticus HY7801 as a probiotic to benefit vaginal health. In vivo, HY7801 reduced the number of Gardnerella vaginalis (GV) and pro-inflammatory cytokines in the vagina of GV-induced BV mice and ameliorated vaginal histological changes. In vitro, HY7801 exhibited positive resistance to simulated gastrointestinal conditions, showed excellent adherence ability to the female genital epithelium, and had high lactic acid and H₂O₂ production capacity. Furthermore, it was found that HY7801 can alleviate BV because it can suppress the expression of virulence factor genes of GV involved in epithelial cell adhesion and biofilm formation along with antibacterial activity against GV. These results indicate that HY7801 can be used as a promising probiotic strain for the maintenance of a healthy vaginal physiological state.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01208-7.

Vulvovaginal candidiasis and vaginal microflora interaction: Microflora changes and probiotic therapy

Vaginal microbiome is mutually beneficial to the host and has a significant impact on health and disease. Candida species, including Candida albicans, are part of the mucosal flora of most healthy women. Under suitable conditions, they can live in the vulvovaginal mucosa, resulting in symptomatic vulvovaginal candidiasis (VVC). Based on the analysis of 16S ribosomal RNA gene sequences, great progress has been made in exploring the composition and structure of vaginal bacterial community. Moreover, researchers have conducted several studies on whether vaginal microbiome will change during VVC infection. In addition, it has been reported that vaginal colonization of probiotics in vaginal microorganisms, especially Lactobacillus, can effectively reduce the risk of VVC and treat VVC. This review aims to summarize the changes of vaginal microflora during VVC infection, and further point out the possibility of using lactic acid bacteria as probiotics to treat VVC, so as to reduce the adverse consequences of VVC infection and reduce the expensive treatment cost.

Evaluation of the efficacy of Lactobacillus-containing feminine hygiene products on vaginal microbiome and genitourinary symptoms in pre- and postmenopausal women: A pilot randomized controlled trial

As estrogen level decreases with aging, the vaginal mucosa gets thinner, and collagen amount decreases. In addition, the population of Lactobacillus in the vagina declines, increasing the risk of atrophic vaginitis, bacterial vaginosis, and genitourinary symptoms in the postmenopausal women. In this study, we evaluated the effects of Lactobacillus-containing feminine hygiene products on vaginal microbiome and genitourinary symptoms in pre- and postmenopausal women. This was a pilot randomized controlled trial in 35 premenopausal and 35 postmenopausal healthy women. For 4 weeks, treatment 1 group (14 premenopausal and 16 postmenopausal women) used the Lactobacillus-containing feminine soap and cream, and treatment 2 group (15 premenopausal and 14 postmenopausal women) used Lactobacillus-containing feminine gel in addition to soap and cream. The remaining 6 premenopausal and 5 postmenopausal women served as controls without using any products. We then compared the changes in the vaginal microbiota, genitourinary symptoms, and other related biomarkers after completion of treatment. Vaginal pH and pathogenic flora were reduced in both treatment groups compared to control group, which was more significant in the treatment 2 group of postmenopausal women. Genitourinary symptoms significantly improved in 60% of premenopausal women in treatment 1 group and 81.3% of postmenopausal women in treatment 2 group, compared to control group (0%, p = 0.043 and p<0.01 respectively). Overactive bladder symptom scores were significantly improved after using the products in eleven out of twelve postmenopausal women suspected of having overactive bladder. The use of Lactobacillus-containing feminine products was associated with improved vaginal ecosystem and urogenital health compared to control group, especially in those women using feminine gel.

Positive biofilms to guide surface microbial ecology in livestock buildings

The increase in human consumption of animal proteins implies changes in the management of meat production. This is followed by increasingly restrictive regulations on antimicrobial products such as chemical biocides and antibiotics, used in particular to control pathogens that can spread zoonotic diseases. Aligned with the One Health concept, alternative biological solutions are under development and are starting to be used in animal production. Beneficial bacteria able to form positive biofilms and guide surface microbial ecology to limit microbial pathogen settlement are promising tools that could complement existing biosecurity practices to maintain the hygiene of livestock buildings. Although the benefits of positive biofilms have already been documented, the associated fundamental mechanisms and the rationale of the microbial composition of these new products are still sparce. This review provides an overview of the envisioned modes of action of positive biofilms used on livestock building surfaces and the resulting criteria for the selection of the appropriate microorganisms for this specific application. Limits and advantages of this biosecurity approach are discussed as well as the impact of such practices along the food chain, from farm to fork.

Lactobacilli, a Weapon to Counteract Pathogens through the Inhibition of Their Virulence Factors

To date, several studies have reported an alarming increase in pathogen resistance to current antibiotic therapies and treatments. Therefore, the search for effective alternatives to counter their spread and the onset of infections is becoming increasingly important.

Antagonistic activity of Lactiplantibacillus plantarum 6.2 extracted from cocoa fermentation and its supernatant on Gardnerella vaginalis

Search for alternative methods for the treatment of bacterial vaginosis has been growing, and probiotics being among them. The most well-known probiotic microorganisms are lactobacilli, which are naturally present in the vaginal microenvironment. Cocoa fermentation is a source of lactic acid bacteria, with lactobacilli being the most prominent. The aim of this study was to evaluate the antagonistic activity of Lactiplantibacillus plantarum 6.2 a strain of lactobacilli isolated from cocoa fermentation, and its cell-free supernatant on Gardnerella vaginalis. It was shown that Lpb. plantarum 6.2 and its supernatant, used at three concentrations, i.e., 40, 20 and 10 mg/mL, have a strong antagonistic activity against G. vaginalis, with a probable action of proteinaceous bacteriocins; the activity was lost after heat treatment. The ability to exclude and displace G. vaginalis from the adhesion site to vaginal HMVII epithelial cells was also demonstrated by the lactobacilli and the supernatant, with the latter showing a bactericidal effect. Thus, the Lpb. plantarum 6.2 strain presents itself as a good probiotic with potential to be used not only as a therapeutic alternative for vaginosis but also as a complement to existing therapies.

Phenotypic Assessment of Probiotic and Bacteriocinogenic Efficacy of Indigenous LAB Strains from Human Breast Milk

Breast milk is the combination of bioactive compounds and microflora that promote newborn’s proper growth, gut flora, and immunity. Thus, it is always considered the perfect food for newborns. Amongst their bioactives, probiotic communities—especially lactic acid bacteria (LAB)—are characterized from breast milk over the first month of parturition. In this study, seven LAB were characterized phenotypically and genotypically as Levilactobacillus brevis BDUMBT08 (MT673657), L. gastricus BDUMBT09 (MT774596), L. paracasei BDUMBT10 (MT775430), L. brevis BDUMBT11 (MW785062), L. casei BDUMBT12 (MW785063), L. casei BDUMBT13 (MW785178), and Brevibacillus brevis M2403 (MK371781) from human breast milk. Their tolerance to lysozyme, acid, bile, gastric juice, pancreatic juice, and NaCl and potential for mucoadhesion, auto-aggregation, and co-aggregation with pathogens are of great prominence in forecasting their gut colonizing ability. They proved their safety aspects as they were negative for virulence determinants such as hemolysis and biofilm production. Antibiogram of LAB showed their sensitivity to more than 90% of the antibiotics tested. Amongst seven LAB, three isolates (L. brevis BDUMBT08 and BDUMBT11, and L. gatricus BDUMBT09) proved their bacteriocin producing propensity. Although the seven LAB isolates differed in their behavior, their substantial probiotic properties with safety could be taken as promising probiotics for further studies to prove their in vivo effects, such as health benefits, in humans.

Understanding Lactobacillus paracasei and Streptococcus oralis Biofilm Interactions through Agent-Based Modeling

As common commensals residing on mucosal tissues, Lactobacillus species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other organisms in those environments. In this study, we used a combination of in vitro imaging of live biofilms and computational modeling to explore biofilm interactions between Streptococcus oralis, an accessory pathogen in oral candidiasis, and Lactobacillus paracasei, an organism with known probiotic properties. A computational agent-based model was created where the two species interact only by competing for space, oxygen and glucose. Quantification of bacterial growth in live biofilms indicated that S. oralis biomass and cell numbers were much lower than predicted by the model. Two subsequent models were then created to examine more complex interactions between these species, one where L. paracasei secretes a surfactant, and another where L. paracasei secretes an inhibitor of S. oralis growth. We observed that the growth of S. oralis could be affected by both mechanisms. Further biofilm experiments support the hypothesis that L. paracasei may secrete an inhibitor of S. oralis growth, although they do not exclude that a surfactant could also be involved. This contribution shows how agent-based modeling and experiments can be used in synergy to address multiple species biofilm interactions, with important roles in mucosal health and disease. IMPORTANCE We previously discovered a role of the oral commensal Streptococcus oralis as an accessory pathogen. S. oralis increases the virulence of Candida albicans infections in murine oral candidiasis and epithelial cell models through mechanisms which promote the formation of tissue-damaging biofilms. Lactobacillus species have known inhibitory effects on biofilm formation of many microbes, including Streptococcus species. Agent-based modeling has great advantages as a means of exploring multifaceted relationships between organisms in complex environments such as biofilms. Here, we used an iterative collaborative process between experimentation and modeling to reveal aspects of the mostly unexplored relationship between S. oralis and L. paracasei in biofilm growth. The inhibitory nature of L. paracasei on S. oralis in biofilms may be exploited as a means of preventing or alleviating mucosal fungal infections.

Antimicrobial and Prebiotic Activity of Lactoferrin in the Female Reproductive Tract: A Comprehensive Review

Women’s intimate health depends on several factors, such as age, diet, coexisting metabolic disorders, hormonal equilibrium, sexual activity, drug intake, contraception, surgery, and personal hygiene. These factors may affect the homeostasis of the internal environment of the genital tract: the vulva, vagina and cervix. This equilibrium is dependent on strict and complex mutual interactions between epithelial cells, immunocompetent cells and microorganisms residing in this environment. The microbiota of the genital tract in healthy women is dominated by several species of symbiotic bacteria of the Lactobacillus genus. The bacteria inhibit the growth of pathogenic microorganisms and inflammatory processes by virtue of direct and multidirectional antimicrobial action and, indirectly, by the modulation of immune system activity. For the homeostasis of the genital tract ecosystem, antimicrobial and anti-inflammatory peptides, as well as proteins secreted by mucus cells into the cervicovaginal fluid, have a fundamental significance. Of these, a multifunctional protein known as lactoferrin (LF) is one of the most important since it bridges innate and acquired immunity. Among its numerous properties, particular attention should be paid to prebiotic activity, i.e., exerting a beneficial action on symbiotic microbiota of the gastrointestinal and genital tract. Such activity of LF is associated with the inhibition of bacterial and fungal infections in the genital tract and their consequences, such as endometritis, pelvic inflammation, urinary tract infections, miscarriage, premature delivery, and infection of the fetus and newborns. The aim of this article is to review the results of laboratory as well as clinical trials, confirming the prebiotic action of LF on the microbiota of the lower genital tract.

iProbiotics: a machine learning platform for rapid identification of probiotic properties from whole-genome primary sequences

Lactic acid bacteria consortia are commonly present in food, and some of these bacteria possess probiotic properties. However, discovery and experimental validation of probiotics require extensive time and effort. Therefore, it is of great interest to develop effective screening methods for identifying probiotics. Advances in sequencing technology have generated massive genomic data, enabling us to create a machine learning-based platform for such purpose in this work. This study first selected a comprehensive probiotics genome dataset from the probiotic database (PROBIO) and literature surveys. Then, k-mer (from 2 to 8) compositional analysis was performed, revealing diverse oligonucleotide composition in strain genomes and apparently more probiotic (P-) features in probiotic genomes than non-probiotic genomes. To reduce noise and improve computational efficiency, 87 376 k-mers were refined by an incremental feature selection (IFS) method, and the model achieved the maximum accuracy level at 184 core features, with a high prediction accuracy (97.77%) and area under the curve (98.00%). Functional genomic analysis using annotations from gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Rapid Annotation using Subsystem Technology (RAST) databases, as well as analysis of genes associated with host gastrointestinal survival/settlement, carbohydrate utilization, drug resistance and virulence factors, revealed that the distribution of P-features was biased toward genes/pathways related to probiotic function. Our results suggest that the role of probiotics is not determined by a single gene, but by a combination of k-mer genomic components, providing new insights into the identification and underlying mechanisms of probiotics. This work created a novel and free online bioinformatic tool, iProbiotics, which would facilitate rapid screening for probiotics.

Phyto-fabricated Nanoparticles and Their Anti-biofilm Activity: Progress and Current Status

Biofilm is the self-synthesized, mucus-like extracellular polymeric matrix that acts as a key virulence factor in various pathogenic microorganisms, thereby posing a serious threat to human health. It has been estimated that around 80% of hospital-acquired infections are associated with biofilms which are found to be present on both biotic and abiotic surfaces. Antibiotics, the current mainstream treatment strategy for biofilms are often found to be futile in the eradication of these complex structures, and to date, there is no effective therapeutic strategy established against biofilm infections. In this regard, nanotechnology can provide a potential platform for the alleviation of this problem owing to its unique size-dependent properties. Accordingly, various novel strategies are being developed for the synthesis of different types of nanoparticles. Bio-nanotechnology is a division of nanotechnology which is gaining significant attention due to its ability to synthesize nanoparticles of various compositions and sizes using biotic sources. It utilizes the rich biodiversity of various biological components which are biocompatible for the synthesis of nanoparticles. Additionally, the biogenic nanoparticles are eco-friendly, cost-effective, and relatively less toxic when compared to chemically or physically synthesized alternatives. Biogenic synthesis of nanoparticles is a bottom-top methodology in which the nanoparticles are formed due to the presence of biological components (plant extract and microbial enzymes) which act as stabilizing and reducing agents. These biosynthesized nanoparticles exhibit anti-biofilm activity via various mechanisms such as ROS production, inhibiting quorum sensing, inhibiting EPS production, etc. This review will provide an insight into the application of various biogenic sources for nanoparticle synthesis. Furthermore, we have highlighted the potential of phytosynthesized nanoparticles as a promising antibiofilm agent as well as elucidated their antibacterial and antibiofilm mechanism.

Survivability of Collagen-Peptide Microencapsulated Lactic Acid Bacteria during Storage and Simulated Gastrointestinal Conditions

The intracellular homeostasis of lyophilized lactic acid bacteria (LAB) is destroyed by extreme cold stress, resulting in decreased stability. This study aimed to verify the validity of collagen as a potential protective agent for improving microbial stability deteriorated by freezing. The collagen types used in this study were low molecular weight collagen (LC) of less than 1000 Da and low molecular weight collagen-peptide (LCP) of less than 300 Da. By the accelerated stability test according to the addition of each collagen type, a 3% LCP displaying a protective effect on the viability of various LAB strains (Lactoplantibacillus plantarum MG989, Lactococcus lactis MG5125, Enterococcus faecium MG5232, Bifidobacterium animalis ssp. lactis MG741, and Streptococcus thermophilus MG5140) was finally selected. It was evaluated whether LCP enhances bacterial stability, survivability in the gastrointestinal (GI) tract, and heat resistance. LCP significantly improved the viability of all strains in the GI tract compared to sucrose and skim milk, which are conventional protective agents. Based on morphological observations, LCP was uniformly coated on the cell surface, resulting in protective effects against multiple external stress stimuli. Such findings indicate the applicability of LCP as an unprecedented protective agent, which can improve the stability of various probiotics with antifreeze effects.

Lactobacillus plantarum Lp62 exerts probiotic effects against Gardnerella vaginalis ATCC 49154 in bacterial vaginosis

The severe side-effects elicited by conventional antibiotic therapy and the recurrence of Bacterial vaginosis-associated bacteria and bacterial resistance have led to the development of novel alternative therapies, among which genital probiotics are widely used. In this study, we aimed to evaluate the antimicrobial activities of Lactobacillus plantarum Lp62 and its supernatant against Gardnerella vaginalis, using both in vitro and in vivo approaches. In vitro assays were used to evaluate the viability of the strain and the antimicrobial activities of the supernatant in different pH ranges. An in vivo assay was performed on female BALB/c mice, wherein the animals were divided into eight groups: four control groups and four treated groups (for curative and preventive therapies). After infecting and treating the mice, the animals were killed to quantify the bacterial load using qPCR, evaluate leucocyte cellular response, determine vaginal cytokine levels and perform cytokine tissue gene expression. Our analyses revealed significant activity of the strain and its supernatant against G. vaginalis. Preliminary in vitro tests showed that the strain grew with equal efficiency in different pH ranges. Meanwhile, the presence of halo and inhibition of pathogen growth established the significant activity of the supernatant against G. vaginalis. We observed that both micro-organisms are resident bacteria of mouse microbiota and that the lactobacilli population growth was affected by G. vaginalis and vice versa. We also observed that the treated groups, with their low bacterial load, absence of leucocyte recruitment, reduced cytokine levels in the vaginal lavage and normalized cytokine gene expression, successfully controlled the infection.

Lactiplantibacillus plantarum strains isolated from spontaneously fermented cocoa exhibit potential probiotic properties against Gardnerella vaginalis and Neisseria gonorrhoeae

Background

Probiotics are important tools in therapies against vaginal infections and can assist traditional antibiotic therapies in restoring healthy microbiota. Recent research has shown that microorganisms belonging to the genus Lactobacillus have probiotic potential. Thus, this study evaluated the potential in vitro probiotic properties of three strains of Lactiplantibacillus plantarum, isolated during the fermentation of high-quality cocoa, against Gardnerella vaginalis and Neisseria gonorrhoeae. Strains were evaluated for their physiological, safety, and antimicrobial characteristics.

Results

The hydrophobicity of L. plantarum strains varied from 26.67 to 91.67%, and their autoaggregation varied from 18.10 to 30.64%. The co-aggregation of L. plantarum strains with G. vaginalis ranged from 14.73 to 16.31%, and from 29.14 to 45.76% with N. gonorrhoeae. All L. plantarum strains could moderately or strongly produce biofilms. L. plantarum strains did not show haemolytic activity and were generally sensitive to the tested antimicrobials. All lactobacillus strains were tolerant to heat and pH resistance tests. All three strains of L. plantarum showed antimicrobial activity against the tested pathogens. The coincubation of L. plantarum strains with pathogens showed that the culture pH remained below 4.5 after 24 h. All cell-free culture supernatants (CFCS) demonstrated activity against the two pathogens tested, and all L. plantarum strains produced hydrogen peroxide. CFCS characterisation in conjunction with gas chromatography revealed that organic acids, especially lactic acid, were responsible for the antimicrobial activity against the pathogens evaluated.

Conclusion

The three strains of L. plantarum presented significant probiotic characteristics against the two pathogens of clinical importance. In vitro screening identified strong probiotic candidates for in vivo studies for the treatment of vaginal infections.

Protective effect of recombinant Lactobacillus plantarum against H2O2-induced oxidative stress in HUVEC cells

This study probed the protective effect of recombinant Lactobacillus plantarum against hydrogen peroxide (H₂O₂)-induced oxidative stress in human umbilical vein endothelial cells (HUVECs). We constructed a new functional L. plantarum (NC8-pSIP409-alr-angiotensin-converting enzyme inhibitory peptide (ACEIP)) with a double-gene-labeled non-resistant screen as an expression vector. A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) colorimetric assay was carried out to determine the cell viability of HUVEC cells following pretreatment with NC8-pSIP409-alr-ACEIP. Flow cytometry (FCM) was used to determine the apoptosis rate of HUVEC cells. Cysteinyl aspartate specific proteinase (caspase)-3/8/9 activity was also assayed and western blotting was used to determine protein expression of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), inducible nitric oxide synthase (iNOS), nicotinamide adenine dinucleotide phosphate oxidase 2 (gp91phox), angiotensin II (AngII), and angiotensin-converting enzyme 2 (ACE2), as well as corresponding indicators of oxidative stress, such as reactive oxygen species (ROS), mitochondrial membrane potential (MMP), malondialdehyde (MDA), and superoxide dismutase (SOD). NC8-pSIP409-alr-ACEIP attenuated H₂O₂-induced cell death, as determined by the MTT assay. NC8-pSIP409-alr-ACEIP reduced apoptosis of HUVEC cells by FCM. In addition, compared to the positive control, the oxidative stress index of the H₂O₂-induced HUVEC (Hy-HUVEC), which was pretreated by NC8-pSIP409-alr-ACEIP, iNOS, gp91phox, MDA, and ROS, was decreased obviously; SOD expression level was increased; caspase-3 or -9 was decreased, but caspase-8 did not change; Bcl-2/Bax ratio was increased; permeability changes of mitochondria were inhibited; and loss of transmembrane potential was prevented. Expression of the hypertension-related protein (AngII protein) in HUVEC cells protected by NC8-pSIP409-alr-ACEIP decreased and expression of ACE2 protein increased. These plantarum results suggested that NC8-pSIP409-alr-ACEIP protects against H₂O₂-induced injury in HUVEC cells. The mechanism for this effect is related to enhancement of antioxidant capacity and apoptosis.

Vulvovaginal Candidosis (Excluding Mucocutaneous Candidosis): Guideline of the German (DGGG), Austrian (OEGGG) and Swiss (SGGG) Society of Gynecology and Obstetrics (S2k-Level, AWMF Registry Number 015/072, September 2020)

Aim The aim of this official guideline, published and coordinated by the German (DGGG), Austrian (OEGGG) and Swiss (SGGG) Societies of Gynecology and Obstetrics in collaboration with the DMykG, DDG and AGII societies, was to provide consensus-based recommendations obtained by evaluating the relevant literature for the diagnosis, treatment and management of women with vulvovaginal candidosis. Methods This S2k guideline represents the structured consensus of a representative panel of experts with a range of different professional backgrounds commissioned by the Guideline Committee of the above-mentioned societies. Recommendations This guideline gives recommendations for the diagnosis, management, counseling, prophylaxis and screening of vulvovaginal candidosis.

Antimicrobial properties of Lactobacillus cell-free supernatants against multidrug-resistant urogenital pathogens

The healthy vaginal microbiota is dominated by Lactobacillus spp., which provide an important critical line of defense against pathogens, as well as giving beneficial effects to the host. We characterized L. gasseri 1A‐TV, L. fermentum 18A‐TV, and L. crispatus 35A‐TV, from the vaginal microbiota of healthy premenopausal women, for their potential probiotic activities. The antimicrobial effects of the 3 strains and their combination against clinical urogenital bacteria were evaluated together with the activities of their metabolites produced by cell‐free supernatants (CFSs). Their beneficial properties in terms of ability to interfere with vaginal pathogens (co‐aggregation, adhesion to HeLa cells, biofilm formation) and antimicrobial activity mediated by CFSs were assessed against multidrug urogenital pathogens (S. agalactiae, E. coli, KPC‐producing K. pneumoniae, S. aureus, E. faecium VRE, E. faecalis, P. aeruginosa, P. mirabilis, P. vulgaris, C. albicans, C. glabrata). The Lactobacilli tested exhibited an extraordinary ability to interfere and co‐aggregate with urogenital pathogens, except for Candida spp., as well as to adhere to HeLa cells and to produce biofilm in the Lactobacillus combination. Lactobacillus CFSs and their combination revealed a strong bactericidal effect on the multidrug resistant indicator strains tested, except for E. faecium and E. faecalis. The antimicrobial activity was maintained after heat treatment but decreased after enzymatic treatment. All Lactobacilli showed lactic dehydrogenase activity and production of D‐ and L‐lactic acid isomers on Lactobacillus CFSs, while only 1A‐TV and 35A‐TV released hydrogen peroxide and carried helveticin J and acidocin A bacteriocins. These results suggest that they can be employed as a new vaginal probiotic formulation and bio‐therapeutic preparation against urogenital infections. Further, in vivo studies are needed to evaluate human health benefits in clinical situations.

Guideline: Vulvovaginal candidosis (AWMF 015/072, level S2k)

Approximately 70-75% of women will have vulvovaginal candidosis (VVC) at least once in their lifetime. In premenopausal, pregnant, asymptomatic and healthy women and women with acute VVC, Candida albicans is the predominant species. The diagnosis of VVC should be based on clinical symptoms and microscopic detection of pseudohyphae. Symptoms alone do not allow reliable differentiation of the causes of vaginitis. In recurrent or complicated cases, diagnostics should involve fungal culture with species identification. Serological determination of antibody titres has no role in VVC. Before the induction of therapy, VVC should always be medically confirmed. Acute VVC can be treated with local imidazoles, polyenes or ciclopirox olamine, using vaginal tablets, ovules or creams. Triazoles can also be prescribed orally, together with antifungal creams, for the treatment of the vulva. Commonly available antimycotics are generally well tolerated, and the different regimens show similarly good results. Antiseptics are potentially effective but act against the physiological vaginal flora. Neither a woman with asymptomatic colonisation nor an asymptomatic sexual partner should be treated. Women with chronic recurrent Candida albicans vulvovaginitis should undergo dose-reducing maintenance therapy with oral triazoles. Unnecessary antimycotic therapies should always be avoided, and non-albicans vaginitis should be treated with alternative antifungal agents. In the last 6 weeks of pregnancy, women should receive antifungal treatment to reduce the risk of vertical transmission, oral thrush and diaper dermatitis of the newborn. Local treatment is preferred during pregnancy.

Vulvovaginal Candidosis: Current Concepts, Challenges and Perspectives

Vulvovaginal candidosis (VVC) is a frequently occurring infection of the lower female genital tract, mostly affecting immuno-competent women at childbearing age. Candida albicans is the most prevalent pathogenic yeast—apart from other non-albicans species—related to this fungal infection. Different virulence factors of C. albicans have been identified, which increase the risk of developing VVC. To initiate treatment and positively influence the disease course, fast and reliable diagnosis is crucial. In this narrative review, we cover the existing state of understanding of the epidemiology, pathogenesis and diagnosis of VVC. However, treatment recommendations should follow current guidelines.

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.

Bacterial vaginosis: Standard treatments and alternative strategies

Bacterial vaginosis (BV) affects many women and has a high influence on their self-esteem, being associated with huge discomfort and changes in the routines, especially the sexual life. International guidelines recommend the administration of metronidazole, clindamycin or tinidazole orally or intravaginally as the standard treatment. However, the treatment with these antibiotics is associated with high levels of failure and recurrence rates. These may be associated with antibiotic resistance, the inability to eradicate the polymicrobial biofilms, and failure to reestablish acidic pH and the lactobacillus-dominated commensal flora. Therefore, it is emergent to study alternative strategies to replace or to be combined with standard therapies in order to prevent and treat BV more efficiently. Alternative strategies may include antimicrobial substances (other antimicrobials, antiseptics and natural compounds) or substances that aim to reestablish the physiologic vaginal environment (probiotics, prebiotics and acidifying agents) while improving the local immunity response. Besides, the development of formulation strategies and new dosage forms and drug delivery systems can improve treatment efficacy and overcome some limitations associated with conventional products.

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

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

The Role of the Cervicovaginal Microbiome on the Genesis and as a Biomarker of Premalignant Cervical Intraepithelial Neoplasia and Invasive Cervical Cancer

The microbiome is able to modulate immune responses, alter the physiology of the human organism, and increase the risk of viral infections and development of diseases such as cancer. In this review, we address changes in the cervical microbiota as potential biomarkers to identify the risk of cervical intraepithelial neoplasia (CIN) development and invasive cervical cancer in the context of human papillomavirus (HPV) infection. Current approaches for clinical diagnostics and the manipulation of microbiota with the use of probiotics and through microbiota transplantation are also discussed.

The role of Lactobacillus species in the control of Candida via biotrophic interactions

Microbial communities have an important role in health and disease. Candida spp. are ubiquitous commensals and sometimes opportunistic fungal pathogens of humans, colonizing mucosal surfaces of the genital, urinary, respiratory and gastrointestinal tracts and the oral cavity. They mainly cause local mucosal infections in immune competent individuals. However, in the case of an ineffective immune defense, Candida infections may become a serious threat. Lactobacillus spp. are part of the human microbiome and are natural competitors of Candida in the vaginal environment. Lactic acid, low pH and other secreted metabolites are environmental signals sensed by fungal species present in the microbiome. This review briefly discusses the ternary interaction between host, Lactobacillus species and Candida with regard to fungal infections and the potential antifungal and fungistatic effect of Lactobacillus species. Our understanding of these interactions is incomplete due to the variability of the involved species and isolates and the complexity of the human host.

Keeping Candida commensal: how lactobacilli antagonize pathogenicity of Candida albicans in an in vitro gut model

The intestine is the primary reservoir of Candida albicans that can cause systemic infections in immunocompromised patients. In this reservoir, the fungus exists as a harmless commensal. However, antibiotic treatment can disturb the bacterial microbiota, facilitating fungal overgrowth and favoring pathogenicity. The current in vitro gut models that are used to study the pathogenesis of C. albicans investigate the state in which C. albicans behaves as a pathogen rather than as a commensal. We present a novel in vitro gut model in which the fungal pathogenicity is reduced to a minimum by increasing the biological complexity. In this model, enterocytes represent the epithelial barrier and goblet cells limit C. albicans adhesion and invasion. Significant protection against C. albicans-induced necrotic damage was achieved by the introduction of a microbiota of antagonistic lactobacilli. We demonstrated a time-, dose- and species-dependent protective effect against C. albicans-induced cytotoxicity. This required bacterial growth, which relied on the presence of host cells, but was not dependent on the competition for adhesion sites. Lactobacillus rhamnosus reduced hyphal elongation, a key virulence attribute. Furthermore, bacterial-driven shedding of hyphae from the epithelial surface, associated with apoptotic epithelial cells, was identified as a main and novel mechanism of damage protection. However, host cell apoptosis was not the driving mechanism behind shedding. Collectively, we established an in vitro gut model that can be used to experimentally dissect commensal-like interactions of C. albicans with a bacterial microbiota and the host epithelial barrier. We also discovered fungal shedding as a novel mechanism by which bacteria contribute to the protection of epithelial surfaces.This article has an associated First Person interview with the joint first authors of the paper.

Anti-Candida activity of beneficial vaginal lactobacilli in in vitro assays and in a murine experimental model

Vulvovaginal candidiasis (VVC) is one of the most frequent infections affecting women worldwide. Healthy vaginal microbiota is dominated by lactobacilli, which form a strong defense line against pathogens. In this work, in vitro antimicrobial properties of thirty vaginal Lactobacillus strains were evaluated against eleven Candida vaginal clinical isolates, employing three different methods. Also, the effect of intravaginal (i.va.) administrations (preventive, therapeutic and preventive-therapeutic) of L. reuteri CRL1324 or L. rhamnosus CRL1332 strains against the i.va. challenge with Candida albicans C2 (C.a.) was evaluated in a murine experimental model. From the results of agar overlay and liquid medium assays the selected lactobacilli strains have shown to inhibit the growth of at least one Candida strain. The inhibition was mainly due to the effect of organic acids. Anti-Candida activity was not evidenced in the agar plate diffusion method. In the experimental murine model, only preventive-therapeutic administration of both lactobacilli was able to significantly reduce viable C.a. numbers recovered in vaginal washes and the leukocyte influx induced by the fungi. In conclusion, lactobacilli exhibited in vitro and in vivo antimicrobial effects on Candida, suggesting that they could be promising candidates for protection against VVC.

An introduction of the role of probiotics in human infections and autoimmune diseases

During the last decades, studies exploring the role of microorganisms inhabiting human body in different scenarios have demonstrated the great potential of modulating them to treat and prevent diseases. Among the most outstanding applications, probiotics have been used for over a century to treat infections and inflammation. Despite the beneficial role of other probiotics, Lactobacillus and Bifidobacterium species are the most frequently used, and have been effective as a therapeutic option in the treatment/prevention of dental caries, periodontal diseases, urogenital infections, and gastrointestinal infections. Additionally, as gastrointestinal tract harbors a great diversity of microbial species that directly or indirectly modulate host metabolism and immune response, the influence of intestinal microbiota, one of the targets of therapies using probiotics, on the biology of immune cells can be explored to treat inflammatory disorders or immune-mediated diseases. Thus, it is not surprising that probiotics have presented promising results in modulating human inflammatory diseases such as type 1 diabetes, multiple sclerosis, rheumatoid arthritis and inflammatory bowel disease, among others. Hence, the purpose of this review is to discuss the potential of therapeutic approaches using probiotics to constrain infection and development of inflammation on human subjects.

Probiotics as antifungal agents: Experimental confirmation and future prospects

Fungal burden throughout the world is very high and it keeps escalating due to increasing numbers of immunocompromised individuals. In contrast, the drugs used in management of fungal infections are so few some with high toxicity. Furthermore, highly resistant fungal pathogens are emerging for example Candida auris, Candida glabrata, Candida gullemondii and Aspergillus species among others. Thus now, more than ever, there is a need for combined efforts and an all round search for possible solutions to curb these problems. Therefore, the role of probiotics in management of fungal infections is indispensable. In fact, the antimicrobial activity of probiotics has been screened with promising results against microbial pathogens. Although, recent reports indicated that probiotics may also contribute to protect against fungal infections, the research done in checking antifungal activity of probiotics has used varied technology. This calls for harmonization of the methods used to screen and confirm the antimicrobial activity of probiotics and other candidate microorganisms. We therefore sought to address issues of disparity in probiotic research and their outcomes. Thus this paper is in order as it comprehensively reviews' publications, provides a summary of the methods and future prospects of probiotics as antifungal agents.

Comparative genomics of human Lactobacillus crispatus isolates reveals genes for glycosylation and glycogen degradation: implications for in vivo dominance of the vaginal microbiota

BACKGROUND

A vaginal microbiota dominated by lactobacilli (particularly Lactobacillus crispatus) is associated with vaginal health, whereas a vaginal microbiota not dominated by lactobacilli is considered dysbiotic. Here we investigated whether L. crispatus strains isolated from the vaginal tract of women with Lactobacillus-dominated vaginal microbiota (LVM) are pheno- or genotypically distinct from L. crispatus strains isolated from vaginal samples with dysbiotic vaginal microbiota (DVM).

RESULTS

We studied 33 L. crispatus strains (n = 16 from LVM; n = 17 from DVM). Comparison of these two groups of strains showed that, although strain differences existed, both groups degraded various carbohydrates, produced similar amounts of organic acids, inhibited Neisseria gonorrhoeae growth, and did not produce biofilms. Comparative genomics analyses of 28 strains (n = 12 LVM; n = 16 DVM) revealed a novel, 3-fragmented glycosyltransferase gene that was more prevalent among strains isolated from DVM. Most L. crispatus strains showed growth on glycogen-supplemented growth media. Strains that showed less-efficient (n = 6) or no (n = 1) growth on glycogen all carried N-terminal deletions (respectively, 29 and 37 amino acid deletions) in a putative pullulanase type I protein.

DISCUSSION

L. crispatus strains isolated from LVM were not phenotypically distinct from L. crispatus strains isolated from DVM; however, the finding that the latter were more likely to carry a 3-fragmented glycosyltransferase gene may indicate a role for cell surface glycoconjugates, which may shape vaginal microbiota-host interactions. Furthermore, the observation that variation in the pullulanase type I gene is associated with growth on glycogen discourages previous claims that L. crispatus cannot directly utilize glycogen.

Detection of vaginal lactobacilli as probiotic candidates

The vaginal microbiota of healthy women is dominated by lactobacilli, which exerts important health-promoting effects to the host. In the present study, 261 lactobacilli isolated from vagina of healthy women were screened for their potential probiotic characteristics. Safety features (haemolytic activity, antibiotic susceptibility, bile salt hydrolase activity) and functional properties (resistance to low pH and bile salts, lysozyme tolerance, gastrointestinal survival, antagonistic activity against pathogens, hydrophobicity, auto-aggregation, and co-aggregation abilities, hydrogen peroxide production, biofilm formation, exopolysaccharide production, adhesion capacity to both normal human vagina epithelial cells and Caco-2 epithelial cells, and lactic acid production) were in depth evaluated. Seven strains, identified as Lactobacillus rhamnosus, Lactobacillus helveticus and Lactobacillus salivarius fulfilled the criteria described above. Therefore, the vaginal ecosystem represents a suitable source of probiotic candidates that could be used in new functional formulates for both gastrointestinal and vaginal eubiosis.

Antifungal activities against Candida albicans, of cell-free supernatants obtained from probiotic Pediococcus acidilactici HW01

OBJECTIVE

The aim of this study was to investigate the antifungal activities of cell-free supernatants of a probiotic strain, Pediococcus acidilactici HW01, against Candida albicans.

DESIGN

C. albicans was cultured in the presence of different concentration of cell-free supernatants obtained from P. acidilactici HW01 (HW01 CFS) and the growth of C. albicans was determined. C. albicans was incubated with HW01 CFS for 24 h and the biofilm formation of C. albicans was determined by staining crystal violet and by using a scanning electron microscope. Biofilm quantification was determined by 2, 3-Bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay.

RESULTS

HW01 CFS inhibitedC. albicans growth, whereas bacteriocin, which is a well-known antimicrobial peptide of lactic acid bacteria, failed to inhibit C. albicans growth. Pre-treatment and simultaneous treatment with HW01 CFS exhibited a significant inhibition of C. albicans biofilm. Although post-treatment with HW01 CFS did not disrupt the established biofilm of C. albicans at 3 h-incubation, significant reduced C. albicans biofilm was observed after 6 h-incubation in the presence of HW01 CFS.

CONCLUSION

These results suggested that the CFS fromP. acidilactici HW01 was revealed as an effective antifungal agent against C. albicans by reducing the growth and biofilm formation.

Enhanced antifungal activity of bovine lactoferrin-producing probiotic Lactobacillus casei in the murine model of vulvovaginal candidiasis

BACKGROUND

Vulvovaginal candidiasis (VVC) is a common vaginitis caused by Candida species,a frequently recurring condition. Fungal azole-resistant strains with azole-resistance have developed for long and wide explosion to the first-line antifungal azole agent. Bovine lactoferrin (BLF) is a protein from transferrin family secreted by the bovine mammary tissue. Its various biological functions are well known, especially the pronounced antifungal activity.

RESULTS

In the current study, we constructed a Lactobacillus casei strain (L.casei/pPG612.1-BLF), which secreted BLF encoded by a mature secretion vector plasmid pPG612.1, and evaluated its antifungal activity in vitro and in vivo. In a two-layer agar plate in vitro assay, the number of C. albicans CFUs decreased and the average colony size shrunk upon exposure to L. casei/pPG612.1-BLF. In a murine VVC model, the infection burden of mice intra-vaginally pre-inoculated with L. casei/pPG612.1-BLF was lower than in control groups. Furthermore, the infection burden in mice with VVC was reduced when the animals were continually given L. casei/pPG612.1-BLF as a topical treatment for 5 days.

CONCLUSION

Combined, these results suggested that the L. casei/pPG612.1-BLF strain is a promising preventative and therapeutic anti-VVC agent, highlighting the possibility of employing the probiotic L. casei as a vehicle for biotherapy in the female genital tract and exploiting the natural antibiotic antimicrobial peptides for other applications.

Bacterial vaginosis: An insight into the prevalence, alternative treatments regimen and it's associated resistance patterns

Bacterial Vaginosis (BV) is a complex polymicrobial infection of vagina that shifts the paradigms of vaginal flora from lactobacilli to opportunistic pathogens. BV is catagorized by greyish white discharge, pH greater than 4.5. It results in the preterm labor, abortion, pelvic inflammatory disorders, post cesarean infections. BV is associated with Sexually Transmitted Diseases (STDs) or immune deficiency disorders like Human Immunodeficiency Virus, Human Papilloma Virus, Herpes Simplex Virus 1 and 2, and Neisseria gonorrhoeae. The prevalence rate is about 21.2 million (29.2%) worldwide. BV is more frequent in black females as compared to white females, independent of geographical distribution. Globally, BV is treated with the current recommended antibiotic therapy including Metronidazole and Clindamycin. The recurrence rates are 76% and occur within 06 months of treatment due to antibiotic resistance against pathogenic bacteria and their biofilms. The antibiotic resistance is a global health issue which directs the attentions towards other treatments. One of these is the treatment of sex partners, thus helping to stop the recurrence rates in females. However, this method does not show any positive results. Probiotic therapy is an incorporation of Lactobacilli orally or intravaginally for the recolonization of healthy microbes. This therapy has exhibited promising results but some studies revealed that Probiotic therapy does not control the recurrence rate. The other methods are in trials period and none of them are used clinically or commercially available for the treatment. The thermoplastic polyurethane (TPU) intravaginal rings contain lactic acid and metronidazole showed promising results in trials of BV treatment. The vaginal acidifiers are used as an alternative method to maintain the vaginal pH but the process of douching is a major limitation. The activated charcoal is used to treat BV patients in clinical trials showed decrease in the pH with only 3.1% loss of lactobacilli. Phage therapy is a reemerging field to overcome the bacterial resistance. They are host specific and easier to handle. They can be used naturally, synthetically; phage cocktails and phage-antibiotics combination can be used. Phages show auspicious results for the treatment of bacterial infections as compared to antibiotics as they also treat biofilms. This is one of the promising therapy in future to treat infections with no side effects. Phage therapy can be used in pharmaceuticals according to Food and Drug Administration (FDA) guidelines. Taken together, it is suggested that large funding is required by pharmaceutical sector or government for further investigation of bacteriophages to be used against BV pathogenesis.

Alternative and complementary therapies for vulvovaginal candidiasis

When it comes to women's health, treating vaginal infections makes up a high proportion of the gynecological services. Among the forms of vaginitis, vulvovaginal candidiasis (VVC) is considered the second most common. Demand for new treatment alternatives is increasingly relevant, especially for therapies with fewer side effects, better tolerability, and lower cost, while still offering improved quality of life in terms of disease prevention. This study intended to investigate the alternative therapies described for the adjuvant treatment of vulvovaginitis caused by Candida species, including alternative and complementary treatment methods used by women. This literature review is based on articles written in English and Portuguese in the PubMed, Google Scholar, and SciELO databases. This study was conducted for the most part using the Brazilian Government's Capes Periodicals Portal, which directs to Google Scholar and PubMed. Since the 1980s, there has been growing interest in alternative therapies in Brazil, a trend which also began in other Western countries in the second half of the twentieth century. Some alternative treatments include substances with antifungal activity, some substances help restore the balance of the vaginal microbiota, while others have an inhibitory activity on microbial virulence factors. The proper use of therapeutic alternatives can effectively contribute to the treatment of VVC, but it should be remembered that some chemical products, such as boric acid or vinegar, and even natural products such as propolis, garlic, and tea tree may have undesirable side effects, having not been tested by well-designed clinical studies. Even so, alternative therapies in the treatment of VVC do have support in the scientific literature.