Action mechanisms of probiotics on Candida spp. and candidiasis prevention: an update

A Novel Sugar-Free Probiotic Oral Rinse Influences Oral Candida albicans in Children with Down Syndrome Post Complete Oral Rehabilitation: A Pilot Randomized Clinical Trial with 6-Month Follow-Up

Down syndrome (DS), caused by trisomy 21, affects 1 in 600-1000 live births and is associated with distinctive physical features, cognitive impairment, and oral health challenges such as increased susceptibility to dental caries, periodontal disease, and elevated prevalence of oral Candida spp. Barriers to dental care necessitate comprehensive strategies to address the unique oral health needs of children with DS. The aim of the study was to evaluate the effectiveness of a sugar-free probiotic oral rinse versus 0.2% chlorhexidine digluconate in reducing oral Candida albicans (OCA) counts and improving oral health outcomes in children with DS. A double-blind randomized controlled trial (CTRI/2022/10/046847) enrolled 30 children with DS (aged 6-14 years). Baseline evaluations included OCA quantification and oral health assessments (OHI-S and PHP). Following individualized oral rehabilitation, participants were randomized to either a probiotic rinse (Group 1) or chlorhexidine rinse (Group 2) for 2 weeks. OCA and oral health parameters were assessed at baseline (T0), 2 weeks post-rehabilitation (T1), 2 weeks post-rinse (T2), and 6 months post-rinse (T3). Both groups showed significant improvements in OHI-S and PHP scores (p < 0.05). The probiotic group demonstrated significantly lower OCA counts than the chlorhexidine group at T2 and T3 (p = 0.001). Hence, the probiotic oral rinse can be considered a safe, effective method for reducing OCA and improving oral health outcomes in children with DS, advocating its inclusion in oral health management strategies for this population.

In vitro and in vivo activity of 1,2,3,4,6-O-pentagalloyl-glucose against Candida albicans

Invasive fungal infections have become an increasingly serious threat to global human health, underscoring the urgent need for the development of new antifungal drugs. In this study, we found a natural polyphenolic compound 1,2,3,4,6-O-pentagalloyl-glucose (PGG), which is present in various plants and herbs. PGG showed broad-spectrum antifungal activities, enhancing the efficacy of fluconazole. Furthermore, PGG could protect mice against gastrointestinal and systemic infection with Candida albicans. Our mechanistic studies revealed that PGG exerts its antifungal effects partially by binding to the CaEno1 protein to inhibit its activity. As a crucial therapeutic target, Eno1 has been reported to be closely associated with cancer, hypertension, and infectious diseases. Our findings indicated that PGG, a new Eno1 inhibitor, is a potential candidate for further antifungal development.

Limosilactobacillus reuteri AJCR4: A Potential Probiotic in the Fight Against Oral Candida spp. Biofilms

Oral candidiasis is one of the most common infections in the immunocompromised. Biofilms of Candida species can make treatments difficult, leading to oral infection recurrence. This research aimed to isolate a Lactobacillus with anti-Candida effects from the oral cavity. An oral Lactobacillus was isolated in caries-free individuals. The best isolate was evaluated against Candida spp. planktonic and biofilm forms. The bacterial impacts on Candida biofilms' adhesion to acrylic discs were analyzed through an in vitro test. L. reuteri AJCR4 had the best anti-Candida activity in the preliminary screening. Results were promising in both planktonic and biofilms, particularly with C. albicans SC5314 and C. tropicalis ATCC750, where no viable cells were detected when using the cell-free supernatant (undiluted). In C. glabrata ATCC2001 and C. parapsilosis ATCC22019 biofilms, reductions of 3 Log10 and more than 2 Log10, respectively, were noted when using a cell suspension of L. reuteri ACJR4 (108 CFU/mL). On polymethyl methacrylate acrylic discs, the cell-free supernatant reduced Candida adhesion, resulting in no viable cell detection on the surface. In conclusion, L. reuteri AJCR4 demonstrated notable antifungal activity against Candida biofilms. This oral isolate and its postbiotic can be a potential alternative strategy to oral candidiasis, especially to treat recalcitrant infections.

Vaginal prevention of Candida albicans: synergistic effect of lactobacilli and mannan oligosaccharides (MOS)

Vulvovaginal candidiasis (VVC) affects approximately 30-50% of women at least once during their lifetime, causing uncomfortable symptoms and limitations in their daily quality of life. Antifungal therapy is not very effective, does not prevent recurrencies and usually causes side effects. Therefore, alternative therapies are urgently needed. The goal of this work was to investigate the potential benefits of using mannan oligosaccharides (MOS) extracts together with a Lactobacillus sp. pool, composed by the most significant species present in the vaginal environment, to prevent infections by Candida albicans. Microbial growth of isolated strains of the main vaginal lactobacilli and Candida strains was assessed in the presence of MOS, to screen their impact upon growth. A pool of the lactobacilli was then tested against C. albicans in competition and prophylaxis studies; bacterial and yeast cell numbers were quantified in specific time points, and the above-mentioned studies were assessed in simulated vaginal fluid (SVF). Finally, adhesion to vaginal epithelial cells (HeLa) was also evaluated, once again resorting to simultaneous exposure (competition) or prophylaxis assays, aiming to measure the effect of MOS presence in pathogen adherence. Results demonstrated that MOS extracts have potential to prevent vaginal candidiasis in synergy with vaginal lactobacilli, with improved results than those obtained when using lactobacilli alone. KEY POINTS: Potential benefits of MOS extracts with vaginal lactobacilli to prevent C. albicans infections. MOS impacts on growth of vaginal lactobacilli pool and C. albicans in SVF. MOS extracts in synergy with L. crispatus inhibit C. albicans adhesion in HeLa cells.

Antimycotic prophylaxis with multispecies probiotics against oral candidiasis in new complete denture wearers: A randomized clinical trial

STATEMENT OF PROBLEM

Changes in the oral microbiota of new complete denture wearers are the main cause of oral candidiasis. The drawbacks associated with traditional antimycotic therapies, especially drug resistance, have led to the search for potent therapeutic and prophylaxis agents with less harmful effects, including probiotics. However, investigation of the prophylaxis and preventive effects of probiotics on new complete denture wearers are lacking.

PURPOSE

The purpose of this randomized clinical trial was to assess the prophylactic efficiency of multistrain probiotics (Lactobacillus and Bifidobacterium) in combating oral candidiasis in new complete denture wearers. The Candida relapse after 4 weeks of intervention cessation was also evaluated.

MATERIAL AND METHODS

A total of 50 new maxillary and mandibular complete denture wearers with asymptomatic detectable levels of Candida were enrolled. The participants in the probiotics group received a daily dose of probiotic lozenges for 8 weeks versus placebo tablets taken by those in the placebo group. Collected mouth-rinse samples were microbiologically assessed to count Candida colonies and identify different species at different time intervals: baseline, 2 weeks after denture delivery, 4 and 8 weeks after the beginning of intervention, and 4 weeks postintervention follow-up. Data were assessed by performing the Shapiro-Wilk test to check the normality of the colony count, while the difference in the colony count between timelines was analyzed using the Freidman test followed by multiple comparison tests (α=.05).

RESULTS

Two weeks after denture delivery, the Candida load had not risen significantly from the baseline count (P>.05). After the intervention, the probiotics had reduced the Candida count significantly in the fourth week and in subsequent follow-up periods, with the highest decrease observed in the eighth week, recording a median count of (0.00) compared with (2.74) at the baseline level (P<.001). Furthermore, in assessing the differential count of Candida species, a noteworthy decrease was found in the level of the most prevalent Candida albicans in the eighth week, with a relapse noticed in the twelfth week of posttreatment follow-up.

CONCLUSIONS

Probiotic lozenges had antimycotic efficiency in asymptomatic new complete denture wearers, with short-term extended preventive effects after intervention cessation.

Exploring the antifungal, antibiofilm and antienzymatic potential of Rottlerin in an in vitro and in vivo approach

Candida species have been responsible for a high number of invasive infections worldwide. In this sense, Rottlerin has demonstrated a wide range of pharmacological activities. Therefore, this study aimed to evaluate the antifungal, antibiofilm and antivirulence activity of Rottlerin in vitro against Candida spp. and its toxicity and antifungal activity in vivo. Rottlerin showed antifungal activity against all yeasts evaluated, presenting Minimum Inhibitory and Fungicidal Concentration (MIC and MFC) values of 7.81 to > 1000 µg/mL. Futhermore, it was able to significantly inhibit biofilm production, presenting Biofilm Inhibitory Concentration (MICB50) values that ranged from 15.62 to 250 µg/mL and inhibition of the cell viability of the biofilm by 50% (IC50) from 2.24 to 12.76 µg/mL. There was a considerable reduction in all hydrolytic enzymes evaluated, with emphasis on hemolysin where Rottlerin showed a reduction of up to 20%. In the scanning electron microscopy (SEM) analysis, Rottlerin was able to completely inhibit filamentation by C. albicans. Regarding in vivo tests, Rottlerin did not demonstrate toxicity at the therapeutic concentrations demonstrated here and was able to increase the survival of C. elegans larvae infected. The results herein presented are innovative and pioneering in terms of Rottlerin's multipotentiality against these fungal infections.

The role of probiotics as adjunct treatment in the prevention and management of gynecological infections: An updated meta-analysis of 35 RCT studies

OBJECTIVE

The present study aims to conduct a comprehensive meta-analysis of randomized controlled trials (RCTs) investigating the efficacy of probiotics as an adjunct treatment for preventing and treating gynecological infections.

MATERIALS AND METHODS

The study adopted a systematic review of scientific databases including PubMed, Cochrane, and EMBASE, using defined MeSH terms. The inclusion and exclusion criteria were set to refine the search, with the data extraction and quality assessment being conducted by two independent investigators.

RESULTS

A total of 35 articles, comprising 3751 patients, were included in the meta-analysis. The application of probiotics demonstrated a notable increase in the cure rates of bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) as compared to control groups. A significant BV cure rate (OR: 5.972; 95% CI: 2.62-13.59; p-value: 0.01) was noted with probiotic use, which was even more pronounced when used as an adjunctive treatment with antibiotics (OR: 2.504; 95% CI: 1.03-6.06; p-value: 0.04). Additionally, probiotic use significantly reduced the recurrence rates of BV (OR: 0.34; 95% CI: 0.167-0.71; p-value: 0.004). For VVC, a significant increase in the cure rate was observed in the probiotic group (OR: 3.425; 95% CI: 2.404-4.879; p-value: 0.01), along with a lower recurrence rate (OR: 0.325; 95% CI: 0.175-0.606; p-value: 0.01).

CONCLUSION

Our findings underscore the potential role of probiotics as a beneficial adjunctive treatment for gynecological infections, indicating an improved cure rate and decreased recurrence. However, additional well-designed studies are necessary to corroborate these findings.

The evil companion of OSCC: Candida albicans

OBJECTIVE

Microbial dysbiosis and microbiome-induced inflammation may play a role in the etiopathogenesis of oral squamous cell carcinoma (OSCC). Candida albicans (C. albicans) is the most prevalent opportunistic pathogenic fungus in the oral cavity, and Candida infection is considered as one of its high-risk factors. Although oral microbiota-host interactions are closely associated with the development of OSCC, the interrelationship between fungi and OSCC is poorly understood compared to that between bacteria and viruses.

RESULTS

We accumulated knowledge of the evidence, pathogenic factors, and possible multiple mechanisms by which C. albicans promotes malignant transformation of OSCC, focusing on the induction of epithelial damage, production of carcinogens, and regulation of the tumor microenvironment. In addition, we highlight the latest treatment strategies for Candida infection.

CONCLUSION

This review provides a new perspective on the interrelationship between C. albicans and OSCC and contributes to the establishment of a systematic and reliable clinical treatment system for OSCC patients with C. albicans infection.

Cell pleomorphism and changes in the enzymatic profile of selected Candida albicans strains in interaction with Escherichia coli - pilot study

Interactions between C. albicans and the microbiota play an important role in maintaining the balance between commensal and pathogenic organisms. Although the exact role of bacteria in reducing the pathogenicity of yeast remains poorly understood, a few examples have been documented so far: probiotics administration effectively reduces the formation of biofilm and bacterial metabolites inhibit the formation of hyphae. The aim of the study was to analyze C. albicans virulence levels based on the changes in the morphological structure and enzymatic profile in experimental cultures mixed with Escherichia coli. Viable cell abundance, cell pleomorphism and enzymatic profile were analyzed in single and mixed cultures (C. albicans + E. coli). The microscope analysis showed a large decrease in the number of viable C. albicans cells in mixed cultures with E. coli from 485.3±132.1 immediately after the establishment of the culture to 238.1±71.2 after an hour of incubation and 24.4±5.4 after 24 h. The length of C. albicans cells differed significantly between the single-species cultures and the mixed cultures for 24 h. Our present findings indicate a significant reduction in the secretion of several enzymes by fungi following contact with E. coli, including acid phosphatase, N-acetyl-β-glucosaminidase, naphthol-AS-BI-phosphohydrolase and leucine arylamidase. The interactions between fungi and bacteria appear to be extremely complex. On the one hand, during C. albicans with E. coli co-incubation, the bacteria stimulated the elongation of yeast cells, leading to the formation of a filamentous form; however, the number of yeast cells and their enzymatic activity decreased significantly. Therefore, it can be concluded that while E. coli stimulates some pathogenic properties, e.g. cell elongation, it also inhibits other virulence features, e.g. enzymatic activity of C. albicans.

Coccidioidomycosis and Host Microbiome Interactions: What We Know and What We Can Infer from Other Respiratory Infections

Between 70 and 80% of Valley fever patients receive one or more rounds of antibiotic treatment prior to accurate diagnosis with coccidioidomycosis. Antibiotic treatment and infection (bacterial, viral, fungal, parasitic) often have negative implications on host microbial dysbiosis, immunological responses, and disease outcome. These perturbations have focused on the impact of gut dysbiosis on pulmonary disease instead of the implications of direct lung dysbiosis. However, recent work highlights a need to establish the direct effects of the lung microbiota on infection outcome. Cystic fibrosis, chronic obstructive pulmonary disease, COVID-19, and M. tuberculosis studies suggest that surveying the lung microbiota composition can serve as a predictive factor of disease severity and could inform treatment options. In addition to traditional treatment options, probiotics can reverse perturbation-induced repercussions on disease outcomes. The purpose of this review is to speculate on the effects perturbations of the host microbiome can have on coccidioidomycosis progression. To do this, parallels are drawn to aa compilation of other host microbiome infection studies.

Bee Pollen and Probiotics' Potential to Protect and Treat Intestinal Permeability in Propionic Acid-Induced Rodent Model of Autism

Rodent models may help investigations on the possible link between autism spectrum disorder (ASD) and gut microbiota since autistic patients frequently manifested gastrointestinal troubles as co-morbidities. Thirty young male rats were divided into five groups: Group 1 serves as control; Group 2, bee pollen and probiotic-treated; and Group 3, propionic acid (PPA)-induced rodent model of autism; Group 4 and Group 5, the protective and therapeutic groups were given bee pollen and probiotic combination treatment either before or after the neurotoxic dose of PPA, respectively. Serum occludin, zonulin, lipid peroxides (MDA), glutathione (GSH), glutathione-S-transferase (GST), glutathione peroxidase (GPX), catalase, and gut microbial composition were assessed in all investigated groups. Recorded data clearly indicated the marked elevation in serum occludin (1.23 ± 0.15 ng/mL) and zonulin (1.91 ± 0.13 ng/mL) levels as potent biomarkers of leaky gut in the PPA- treated rats while both were normalized to bee pollen/probiotic-treated rats. Similarly, the high significant decrease in catalase (3.55 ± 0.34 U/dL), GSH (39.68 ± 3.72 µg/mL), GST (29.85 ± 2.18 U/mL), and GPX (13.39 ± 1.54 U/mL) concomitant with a highly significant increase in MDA (3.41 ± 0.12 µmoles/mL) as a marker of oxidative stress was also observed in PPA-treated animals. Interestingly, combined bee pollen/probiotic treatments demonstrated remarkable amelioration of the five studied oxidative stress variables as well as the fecal microbial composition. Overall, our findings demonstrated a new approach to the beneficial use of bee pollen and probiotic combination as a therapeutic intervention strategy to relieve neurotoxic effects of PPA, a short-chain fatty acid linked to the pathoetiology of autism.

Efficacy of Probiotics Compared to Chlorhexidine Mouthwash in Improving Periodontal Status: A Systematic Review and Meta-Analysis

Purpose

To critically evaluate the available literature and conduct a systematic review of recent randomized controlled trials to assess the effectiveness of probiotics compared to chlorhexidine mouthwash in enhancing periodontal health.

Methods

Five databases were searched electronically, as well as the gray literature. Using the Cochrane risk-of-bias tool for randomized clinical trials, the risk of bias was examined. The weighted mean difference (WMD) method was used to calculate the effect sizes. Heterogeneity was assessed using I ² and τ ² statistics. The GRADE approach was adopted to assess the certainty of the evidence. To assess the robustness of the findings, sensitivity analysis and publication bias assessment were undertaken.

Results

A total of 1850 studies were initially identified. Sixteen clinical trials were eligible for qualitative synthesis, and ten were included in the meta-analysis. In terms of the gingival index, in total, no statistically significant difference was observed between chlorhexidine and probiotics within 4 weeks (WMD -0.03, 95% CI: -0.09∼0.04, P = 0.3885). Similar to GI, no statistically significant difference was observed between chlorhexidine and probiotics regarding the plaque index within 4 weeks (WMD 0.11, 95% CI: -0.05∼0.28, P = 0.1726). No statistically significant difference was observed between chlorhexidine and probiotics in all time intervals regarding oral hygiene index-simplified (WMD -0.01, 95% CI: -0.05∼0.04, P = 0.7508). The robustness of these findings was confirmed by sensitivity analysis and publication bias assessments.

Conclusions

Based on the findings, probiotics were an acceptable alternative to conventional chlorhexidine in improving periodontal health. High-quality studies with rigorous methodology should be conducted to assess the optimum doses of probiotics for clinical implications.

Effect of synbiotic mouthwash on oral mucositis induced by radiotherapy in oral cancer patients: a double-blind randomized clinical trial

PURPOSE

Considering the complex pathobiology of oral mucositis, especially in oral cancer patients, the prevention and treatment of oral mucositis in patients undergoing radiotherapy remains an essential and clinically crucial unmet need. The present study aims to investigate and compare the effects of synbiotic mouthwash with normal saline mouthwash on the prevention and control of radiotherapy-induced oral mucositis in oral cancer patients.

METHODS

Double-blind, randomized clinical trial (RCT) performed on 64 oral cancer patients who underwent radiotherapy (IRCT20201106049288N1, registration date: 2020-12-23). Patients were divided randomly into the case (32 subjects) and control (32 subjects) groups. All patients underwent intensity-modulated radiotherapy and received 6000 cGY of radiotherapy in 34 fractions. All patients received the usual treatment for mucositis, but in the case group, synbiotic mouthwash was prescribed and in the control group, normal saline mouthwash was prescribed from a day before the start to the end of radiotherapy treatment. Patients were monitored every session for 6 weeks to check the progression, oral involvement severity, and mucositis grade.

RESULTS

The case group showed a significant reduction in the oral mucositis severity. The mucositis grade in the case group from the 7th session of oral examination was significantly lower than the control (p < 0.05), and this significant difference persisted until the last session of oral examination. Incidence rates of severe oral mucositis (grade 3) during the treatment period were 11.59% in the case and 36.45% in control (p < 0.001).

CONCLUSION

Synbiotic mouthwash significantly reduces and prevents oral mucositis intensity in oral cancer patients undergoing radiotherapy.

Antimicrobial and Antibiofilm Effect of Inulin-Type Fructans, Used in Synbiotic Combination with Lactobacillus spp. Against Candida albicans

There is great interest in the search for new alternatives to antimicrobial drugs, and the use of prebiotics and probiotics is a promising approach to this problem. This study aimed to assess the effect of inulin-type fructans, used in synbiotic combinations with Lactobacillus paracasei or Lactobacillus plantarum, on the production of short-chain fatty acids and antimicrobial activity against Candida albicans. The inhibition assay using the L. paracasei and L. plantarum supernatants resulting from the metabolization of inulin-type fructans displayed growth inhibition and antibiofilm formation against C. albicans. Inhibition occurred at concentrations of 12.5, 25, and 50% of the L. paracasei supernatant and at a concentration of 50% of the L. plantarum supernatant. The analysis of short-chain fatty acids by gas chromatography showed that lactic acid was the dominating produced metabolite. However, acetic, propionic, and butyric acids were also detected in supernatants from both probiotics. Therefore, the synbiotic formulation of L. paracasei or L. plantarum in the presence of inulin-type fructans constitutes with anticandidal effect is a possible option to produce antifungal drugs or antimicrobial compounds.

The Antibiofilm Role of Biotics Family in Vaginal Fungal Infections

“Unity in strength” is a notion that can be exploited to characterize biofilms as they bestow microbes with protection to live freely, escalate their virulence, confer high resistance to therapeutic agents, and provide active grounds for the production of biofilms after dispersal. Naturally, fungal biofilms are inherently resistant to many conventional antifungals, possibly owing to virulence factors as their ammunitions that persistently express amid planktonic transition to matured biofilm state. These ammunitions include the ability to form polymicrobial biofilms, emergence of persister cells post-antifungal treatment and acquisition of resistance genes. One of the major disorders affecting vaginal health is vulvovaginal candidiasis (VVC) and its reoccurrence is termed recurrent VVC (RVVC). It is caused by the Candida species which include Candida albicans and Candida glabrata. The aforementioned Candida species, notably C. albicans is a biofilm producing pathogen and habitually forms part of the vaginal microbiota of healthy women. Latest research has implicated the role of fungal biofilms in VVC, particularly in the setting of treatment failure and RVVC. Consequently, a plethora of studies have advocated the utilization of probiotics in addressing these infections. Specifically, the excreted or released compounds of probiotics which are also known as postbiotics are being actively researched with vast potential to be used as therapeutic options for the treatment and prevention of VVC and RVVC. These potential sources of postbiotics are harnessed due to their proven antifungal and antibiofilm. Hence, this review discusses the role of Candida biofilm formation in VVC and RVVC. In addition, we discuss the application of pro-, pre-, post-, and synbiotics either individually or in combined regimen to counteract the abovementioned problems. A clear understanding of the role of biofilms in VVC and RVVC will provide proper footing for further research in devising novel remedies for prevention and treatment of vaginal fungal infections.

The Use of Probiotics as Adjuvant Therapy of Periodontal Treatment: A Systematic Review and Meta-Analysis of Clinical Trials

For many years, the use of probiotics in periodontitis treatment was reflected in their abilities to control the immune response of the host to the presence of pathogenic microorganisms and to upset periodontopathogens. Accordingly, the aim of the present study was to assess the use of probiotics as adjuvant therapy on clinical periodontal parameters throughout a systematic review and meta-analysis. The literature was screened, up to 4 June 2021, by two independent reviewers (L.H. and R.B.) in four electronic databases: PubMed (MedLine), ISI Web of Science, Scielo, and Scopus. Only clinical trials that report the effect of the use of probiotics as adjuvants in the treatment of periodontal disease were included. Comparisons were carried out using Review Manager Software version 5.3.5 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). A total of 21 studies were considered for the meta-analysis. For the index plaque, the use of probiotics did not improve this clinical parameter (p = 0.16). On the other hand, for the periodontal pocket depth, the clinical attachment loss, the bleeding on probing, and the use of probiotics as adjuvant therapy resulted in an improvement of these parameters, since the control group achieved statistically higher values of this parameter (p < 0.001; p < 0.001; and p = 0.005, respectively). This study suggests that the use of probiotics led to an improvement in periodontal pocket depth, clinical attachment loss, and bleeding on probing parameters. On the other hand, this protocol seems to not be beneficial for the index plaque parameter.

Probiotics for Oral Candidiasis: Critical Appraisal of the Evidence and a Path Forward

Oropharyngeal Candidiasis (OPC) is a mucosal fungal infection that is prevalent among patients with compromised immunity. The success of probiotics in treating chronic diseases with a microbial etiology component at other mucosal sites (i.e., gastro-intestinal, genitourinary and alveolar mucosae) has inspired research into the use of probiotics in the treatment of OPC. A growing body of research in vitro and in animal models indicates that some probiotic species and strains have inhibitory activities against Candida albicans growth, morphological switching, and biofilm formation. However, recent review and meta-analysis studies reveal a dearth of human randomized, controlled clinical trials on the efficacy of probiotics to treat or prevent OPC, while the majority of these have not based their selection of probiotic strains or the type of administration on sound pre-clinical evidence. In this mini-review, we assess the state of the field, outline some of the difficulties in translating lab results to clinical efficacy, and make recommendations for future research needed in order to move the field forward.

Oral Cavity and Candida albicans: Colonisation to the Development of Infection

Candida colonisation of the oral cavity increases in immunocompromised individuals which leads to the development of oral candidiasis. In addition, host factors such as xerostomia, smoking, oral prostheses, dental caries, diabetes and cancer treatment accelerate the disease process. Candida albicans is the primary causative agent of this infection, owing to its ability to form biofilm and hyphae and to produce hydrolytic enzymes and candialysin. Although mucosal immunity is activated, from the time hyphae-associated toxin is formed by the colonising C. albicans cells, an increased number and virulence of this pathogenic organism collectively leads to infection. Prevention of the development of infection can be achieved by addressing the host physiological factors and habits. For maintenance of oral health, conventional oral hygiene products containing antimicrobial compounds, essential oils and phytochemicals can be considered, these products can maintain the low number of Candida in the oral cavity and reduce their virulence. Vulnerable patients should be educated in order to increase compliance.

ANTIMICROBIAL POTENTIAL OF LACTIC ACID BACTERIA LACTOBACILLUS RHAMNOSUS LYSATE

According to World Health Organization, antibiotic resistance is rising to dangerously high levels in all parts of the world. New resistance mechanisms are emerging and spreading globally, threatening our ability to treat common infectious diseases. Therefore, searching for new antimicrobial agents of natural origin is an extraordinary global problem. The work aimed to determine the antimicrobial activity of lyophilized enzymatic lysate of cells of the Lactobacillus rhamnosus V strain of lactic acid bacteria. The object of the study was the drug Del-Imun V®, which hasanti-allergican dimmuno stimulating activity. The researchers' efforts aimed to fully reveal the drug's potential, particularlyitsanti microbialaction. Antimicrobial activity was determined by the minimum inhibitory concentration (MIC). Determination of MIC was carried out by the method of twotime serial dilutions in meat-peptone broth (MPB) for bacteria and liquid wort for yeast. Gram-negative (Escherichia coli IEM-1, Proteus vulgaris PA-12, Pseudomonas sp. MI-2) and Gram-positive (Bacillus subtilis BТ-2, Staphylococcus aureus BМС-1) bacteria, as well as yeast (Candida albicans D-6, Candida tropicalis PE-2, Candida utilis BVS-65). It was shown that MIC valuesof the native preparation for the bacterial test cultures (EscherichiacoliIEM-1, Bacillussubtilis BT-2, Staphylococcusaureus BMS-1, Proteusvulgaris PA-12, Pseudomonassp. MI-2) were 8 time slower, than those of the thermally in activated preparation, forthe yeasts (Candidaalbicans D-6, Candidatropicalis PE-2, Candidautilis BVS-65) – 4-8 time slower. As a result of the conducted research, the antibacterial and antifungal activity of the drugDel-Imun V® was established. The spectrum of antimicrobial activity concerned gram-positiveand gram-negative bacteria and yeast-like fungi of the genus Candida. The minimum inhibitory concentrations were quite low: from 1.0 to 4.0 μg/ml for bacterial cultures and from 62.5 to 125 μg/ml for yeast. The culture of B. subtilis BT-2 was the least sensitive to the drug's action (MIC – 12.5 μg/ml). There fore, it can be concluded that the lysate of Lactobacillus rhamnosus V lacticacid bacteriahasanti bacteria landanti fungal properties.

Living Lactobacillus-ZnO nanoparticles hybrids as antimicrobial and antibiofilm coatings for wound dressing application

Probiotic bacteria are able to produce antimicrobial substances as well as to synthesize green metal nanoparticles (NPs). New antimicrobial and antibiofilm coatings (LAB-ZnO NPs), composed of Lactobacillus strains and green ZnO NPs, were employed for the modification of gum Arabic-polyvinyl alcohol-polycaprolactone nanofibers matrix (GA-PVA-PCL) against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. The physicochemical properties of ZnO NPs biologically synthesized by L. plantarum and L. acidophilus, LAB-ZnO NPs hybrids and LAB-ZnO NPs@GA-PVA-PCL were studied using FE-SEM, EDX, EM, FTIR, XRD and ICP-OES. The morphology of LAB-ZnO NPs hybrids was spherical in range of 4.56-91.61 nm with an average diameter about 34 nm. The electrospun GA-PVA-PCL had regular, continuous and without beads morphology in the scale of nanometer and micrometer with an average diameter of 565 nm. Interestingly, the LAB not only acted as a biosynthesizer in the green synthesis of ZnO NPs but also synergistically enhanced the antimicrobial and antibiofilm efficacy of LAB-ZnO NPs@GA-PVA-PCL. Moreover, the low cytotoxicity of ZnO NPs and ZnO NPs@GA-PVA-PCL on the mouse embryonic fibroblasts cell line led to make them biocompatible. These results suggest that LAB-ZnO NPs@GA-PVA-PCL has potential as a safe promising antimicrobial and antibiofilm dressing in wound healing against pathogens.

Lactobacillus casei reduces the extracellular matrix components of fluconazole-susceptible Candida albicans biofilms

Fluconazole-sensitive (CaS) and -resistant (CaR) C. albicans were grown as single-species and dual-species biofilms with Lactobacillus casei (Lc) and Lactobacillus rhamnosus (Lr). Single-species Lc and Lr were also evaluated. Biofilm analysis included viable plate counts, the extracellular matrix components, biomass, and structural organization. Lc reduced the viability of CaS, water-soluble polysaccharides, and eDNA in CaS + Lc biofilm. Lc biofilm presented more eDNA than CaS. The total biomass of CaS + Lc biofilm was higher than the single-species biofilms. The viability of Lc and Lr was reduced by CaR dual-species biofilms. The total and insoluble biomass in CaS + Lr was higher than in single-species CaS biofilms. Lc hindered the growth of CaS, and their association hampered matrix components linked to the structural integrity of the biofilm. These findings allow understanding of how the implementation of probiotics influences the growth of C. albicans biofilms and thereby helps with the development of novel approaches to control these biofilms.

Recent advances in electrospun nanofiber vaginal formulations for women's sexual and reproductive health

Electrospinning is an innovative technique that allows production of nanofibers and microfibers by applying a high voltage to polymer solutions of melts. The properties of these fibers - which include high surface area, high drug loading capacity, and ability to be manufactured from mucoadhesive polymers - may be particularly useful in a myriad of drug delivery and tissue engineering applications. The last decade has witnessed a surge of interest in the application of electrospinning technology for the fabrication of vaginal drug delivery systems for the treatment and prevention of diseases associated with women's sexual and reproductive health, including sexually transmitted infections (e.g. infection with human immunodeficiency virus and herpes simplex virus) vaginitis, preterm birth, contraception, multipurpose prevention technology strategies, cervicovaginal cancer, and general maintenance of vaginal health. Due to their excellent mechanical properties, electrospun scaffolds are also being investigated as next-generation materials in the surgical treatment of pelvic organ prolapse. In this article, we review the latest advances in the field.

Anticandidal Activities by Lactobacillus Species: An Update on Mechanisms of Action

Lactobacilli are among the most studied bacteria in the microbiome of the orodigestive and genitourinary tracts. As probiotics, lactobacilli may provide various benefits to the host. These benefits include regulating the composition of the resident microbiota, preventing - or even potentially reverting- a dysbiotic state. Candida albicans is an opportunistic pathogen that can influence and be influenced by other members of the mucosal microbiota and, under immune-compromising conditions, can cause disease. Lactobacillus and Candida species can colonize the same mucosal sites; however, certain Lactobacillus species display antifungal activities that can contribute to low Candida burdens and prevent fungal infection. Lactobacilli can produce metabolites with direct anticandidal function or enhance the host defense mechanisms against fungi. Most of the Lactobacillus spp. anticandidal mechanisms of action remain underexplored. This work aims to comprehensively review and provide an update on the current knowledge regarding these anticandidal mechanisms.

Application of probiotics in candidiasis management

Candidiasis (e.g., oral, gastrointestinal, vaginal, urinary tract, systemic) is a worldwide growing problem, since antifungal resistance and immunosuppression states are rising. To address this problem, very few drugs are available for the treatment of Candida spp. infections. Therefore, novel therapeutic strategies are urgently required. Probiotics have been proposed for the prevention and treatment of bacterial infections due to their safety record and efficacy, however, little is still known about their potential role regarding fungal infections. The purpose of this review is to present an updated summary of the evidence of the antifungal effects of probiotics along with a discussion of their potential use as an alternative/complementary therapy against Candida spp. infections. Thus, we performed a literature search using appropriate keywords ("Probiotic + Candida", "Candidiasis treatment", and "Probiotic + candidiasis") to retrieve relevant studies (both preclinical and clinical) with special emphasis on the works published in the last 5 years. An increasing amount of evidence has shown the potential usefulness of probiotics in the management of oral and vulvovaginal candidiasis in recent years. Among other results, we found that, as for bacterial infections, Lactobacillus, Bifidobacterium, and Saccharomyces are the most studied and effective genus for this purpose. However, in other areas, particularly in skincandidiaisis, studies are low or lacking. Thus, further investigation is necessary including in vitro and in vivo studies to establish the usefulness of probiotics in the management of candidiasis.

Glycosaminoglycans Are Involved in the Adhesion of Candida albicans and Malassezia Species to Keratinocytes But Not to Dermal Fibroblasts

BACKGROUND AND OBJECTIVE

Superficial mycoses are some of the most common diseases worldwide. The usual culprits-yeasts belonging to the genera Malassezia and Candida-are commensal species in the skin that can cause opportunistic infections. We aimed to determine whether these yeasts use glycosaminoglycans (GAGs) as adhesion receptors to mediate binding to epithelial cells.

MATERIAL AND METHODS

In keratinocyte and dermal fibroblast cultures, we used rhodamine B and genistein to inhibit GAG synthesis to study the role these molecules play in the adhesion of Candida albicans and Malassezia species to cells. We also analyzed GAG involvement by means of enzyme digestion, using specific lyases.

RESULTS

Rhodamine B partially inhibited the adhesion of both fungi to keratinocytes but not to fibroblasts. Selective digestion of heparan sulfate enhanced the binding of Malassezia species to keratinocytes and of both fungi to fibroblasts. Chondroitin sulfate digestion decreased Calbicans adhesion to keratinocytes, but increased the adhesion of the filamentous forms of this species to fibroblasts.

CONCLUSIONS

Cell surface GAGs appear to play a role in the adhesion of Calbicans and Malasezzia species to keratinocytes. In contrast, their adhesion to fibroblasts appears to be enhanced by GAG inhibition, suggesting that some other type of receptor is the mediator.

In Vivo Efficacy of Lacticaseibacillus rhamnosus L8020 in a Mouse Model of Oral Candidiasis

Oral candidiasis presents with multiple clinical manifestations. Among known pathogenic Candida species, Candida albicans is the most virulent and acts as the main causative fungus of oral candidiasis. Novel treatment modalities are needed because of emergent drug resistance and frequent candidiasis recurrence. Here, we evaluated the ability of Lacticaseibacillus rhamnosus L8020, isolated from healthy and caries-free volunteers, to prevent against the onset of oral candidiasis in a mouse model. Mice were infected with C. albicans, in the presence or absence of L. rhamnosus L8020. The mice were treated with antibiotics and corticosteroid to disrupt the oral microbiota and induce immunosuppression. We demonstrated that oral consumption of L. rhamnosus L8020 by C. albicans-infected mice abolished the pseudomembranous region of the mouse tongue; it also suppressed changes in the expression levels of pattern recognition receptor and chemokine genes. Our results suggest that L. rhamnosus L8020 has protective or therapeutic potential against oral candidiasis, which supports the potential use of this probiotic strain for oral health management.

Mechanisms of Candida Resistance to Antimycotics and Promising Ways to Overcome It: The Role of Probiotics

Pathogenic Candida and infections caused by those species are now considered as a serious threat to public health. The treatment of candidiasis is significantly complicated by the increasing resistance of pathogenic strains to current treatments and the stagnant development of new antimycotic drugs. Many species, such as Candida auris, have a wide range of resistance mechanisms. Among the currently used synthetic and semi-synthetic antifungal drugs, the most effective are azoles, echinocandins, polyenes, nucleotide analogs, and their combinations. However, the use of probiotic microorganisms and/or the compounds they produce is quite promising, although underestimated by modern pharmacology, to control the spread of pathogenic Candida species.

In Vitro Exploration of Probiotic Bacteria Interactions with Candida Using Culture Techniques to Model Dysbiotic Conditions in Colonized Tissues

Candida albicans overgrowth at various mucosal sites is an ongoing and complex clinical concern involving interactions with indigenous microbiota and therapeutic or preventive measures superimposed on the pathogen-microbiome interaction. In this paper we describe the use of quantitative flow cytometry (specific to the cytometer’s sample introduction mechanism) to explore the in vitro interaction between Candida albicans, probiotic lactobacilli and a topical vaginal therapeutic. Our central hypothesis was cytometric measurements of co-cultures of yeast and bacteria could provide a useful method for exploring the dynamics of different microbial species in culture, with and without inhibitors. Two commercial products were used as exemplars for this research, a vaginal antimicrobial gel and two species of probiotic lactobacillus intended or oral administration with crystalline bovine lactoferrin to augment the vaginal gel. The cytometer forward channel height parameter distinguished yeast from bacteria in co-culture experiments in the presence of a vaginal therapeutic gel or components of its formulation including EDTA, glycogen, polydextrose as well as the host defense factor, lactoferrin. Flow cytometry showed lactobacilli influenced yeast counts in co-culture, with the technique lending itself to wide-ranging test conditions including organisms, media composition and screening of various antimicrobials. Key findings: The proprietary vaginal gel augmented the effect of lactobacilli, as did EDTA and lactoferrin. Prebiotic compounds also enhanced Candida inhibition by lactobacilli. Propidium iodide (Fluorescence channel 3) discriminated between necrotic and non-necrotic yeast and bacteria in co-cultures under various culture conditions. This research demonstrates the value of flow cytometry to evaluate the population dynamics of yeast and bacteria in co-culture using a proprietary product and its components. We discuss both the limitations of the current study and describe how methods employed here would be transferrable to the investigation of organisms present in defined cultures or at body sites colonized by fungal species and the effects of therapeutics or probiotics on Candida.

Glycosaminoglycans Are Involved in the Adhesion of Candida albicans and Malassezia Species to Keratinocytes But Not to Dermal Fibroblasts

BACKGROUND AND OBJECTIVE

Superficial mycoses are some of the most common diseases worldwide. The usual culprits - yeasts belonging to the genera Malassezia and Candida - are commensal species in the skin that can cause opportunistic infections. We aimed to determine whether these yeasts use glycosaminoglycans (GAGs) as adhesion receptors to mediate binding to epithelial cells.

MATERIAL AND METHODS

In keratinocyte and dermal fibroblast cultures, we used rhodamine B and genistein to inhibit GAG synthesis to study the role these molecules play in the adhesion of Candida albicans (C. albicans) and Malassezia species to cells. We also analyzed GAG involvement by means of enzyme digestion, using specific lyases.

RESULTS

Rhodamine B partially inhibited the adhesion of both fungi to keratinocytes but not to fibroblasts. Selective digestion of heparan sulfate enhanced the binding of Malassezia species to keratinocytes and of both fungi to fibroblasts. Chondroitin sulfate digestion decreased C. albicans adhesion to keratinocytes, but increased the adhesion of the filamentous forms of this species to fibroblasts.

CONCLUSIONS

Cell surface GAGs appear to play a role in the adhesion of C albicans and Malasezzia species to keratinocytes. In contrast, their adhesion to fibroblasts appears to be enhanced by GAG inhibition, suggesting that some other type of receptor is the mediator.

Oral Administration of Lactobacillus helveticus LA401 and Lactobacillus gasseri LA806 Combination Attenuates Oesophageal and Gastrointestinal Candidiasis and Consequent Gut Inflammation in Mice

Candida albicans is an opportunistic pathogen that causes mucosal gastrointestinal (GI) candidiasis tightly associated with gut inflammatory status. The emergence of drug resistance, the side effects of currently available antifungals and the high frequency of recurrent candidiasis indicate that new and improved therapeutics are needed. Probiotics have been suggested as a useful alternative for the management of candidiasis. We demonstrated that oral administration of Lactobacillus gasseri LA806 alone or combined with Lactobacillus helveticus LA401 in Candida albicans-infected mice decrease the Candida colonization of the oesophageal and GI tract, highlighting a protective role for these strains in C. albicans colonization. Interestingly, the probiotic combination significantly modulates the composition of gut microbiota towards a protective profile and consequently dampens inflammatory and oxidative status in the colon. Moreover, we showed that L. helveticus LA401 and/or L. gasseri LA806 orient macrophages towards a fungicidal phenotype characterized by a C-type lectin receptors signature composed of Dectin-1 and Mannose receptor. Our findings suggest that the use of the LA401 and LA806 combination might be a promising strategy to manage GI candidiasis and the inflammation it causes by inducing the intrinsic antifungal activities of macrophages. Thus, the probiotic combination is a good candidate for managing GI candidiasis by inducing fungicidal functions in macrophages while preserving the GI integrity by modulating the microbiota and inflammation.

Lactobacillus rhamnosus strains of oral and vaginal origin show strong antifungal activity in vitro

Background: Intake of probiotic bacteria may prevent oral Candida infection. Objective: To screen the antifungal activity of 14 Lactobacillus candidate strains of human origin, against six opportunistic C. albicans and non-albicans species. A second aim was to study the acid production of the four strains showing the strongest antifungal activity. Methods: We used an agar overlay growth inhibition assay to the assess the antifungal activity of the lactobacilli. The acid-producing capacity was measured with pH micro-sensors. Results: All 14 Lactobacillus candidates inhibited the growth of the Candida spp. The four best-performing strains were L. rhamnosus DSM 32992 (oral origin), L. rhamnosus DSM 32991 (oral), L. jensenii 22B42 (vaginal), and L. rhamnosus PB01 (vaginal). The difference between L. rhamnosus DSM 32992 and the other three strains was statistically significant (p < 0.001). The Candida spp. differed in susceptibility; C. parapsilosis was highly inhibited, while C. krusei was not or slightly inhibited. The oral L. rhamnosus DSM 32992 and DSM 32991 strains showed the lowest pH-values. Conclusion: Screening of probiotic lactobacilli showed significant strain-dependent variations in their antifungal capacity in a pH-dependent mode. Two strains of oral origin were most effective. A further characterization seems justified to elaborate on their probiotic properties.

Identification of sulfur components enhancing the anti-Candida effect of Lactobacillus rhamnosus Lcr35

GYNOPHILUS (Lcr REGENERANS) is a live biotherapeutic product (LBP) aimed at restoring the vaginal microbiome and contains the live biotherapeutic microorganism Lactobacillus rhamnosus Lcr35. In this study, the LBP formulation and manufacturing process significantly enhanced the anti-Candida activity of L. rhamnosus Lcr35, with a complete loss of viability of the yeast after 48 h of coincubation. Sodium thiosulfate (STS), one excipient of the product, was used as a potentiator of the anti-Candida spp. activity of Lactobacilli. This contact-independent phenomenon induced fungal cell disturbances, as observed by electron microscopy observations. Nonverbal sensory experiments showed clear odor dissimilarities between cocultures of L. rhamnosus Lcr35 and C. albicans in the presence and absence of STS, suggesting an impact of odor-active metabolites. A volatolomic approach allowed the identification of six odor-active compounds, including one sulfur compound that was identified as S-methyl thioacetate (MTA). MTA was associated with the antifungal effect of Lcr35, and its functional link was established in vitro. We show for the first time that the LBP GYNOPHILUS, which is a highly active product in the reduction of vulvovaginal candidiasis, requires the presence of a sulfur compound to fully achieve its antifungal effect.

The antifungal pipeline: the need is established. Are there new compounds?

Our review summarizes and compares the temporal development (eras) of antifungal drug discovery as well as antibacterial ventures. The innovation gap that occurred in antibacterial discovery from 1960 to 2000 was likely due to tailoring of existing compounds to have better activity than predecessors. Antifungal discovery also faced innovation gaps. The semi-synthetic antibiotic era was followed closely by the resistance era and the heightened need for new compounds and targets. With the immense contribution of comparative genomics, antifungal targets became part of the discovery focus. These targets by definition are absolutely required to be fungal- or even lineage (clade) specific. Importantly, targets need to be essential for growth and/or have important roles in disease and pathogenesis. Two types of antifungals are discussed that are mostly in the FDA phase I–III clinical trials. New antifungals are either modified to increase bioavailability and stability for instance, or are new compounds that inhibit new targets. One of the important developments in incentivizing new antifungal discovery has been the prolific number of publications of global and country-specific incidence. International efforts that champion global antimicrobial drug discovery are discussed. Still, interventions are needed. The current pipeline of antifungals and alternatives to antifungals are discussed including vaccines.