Application of probiotics in candidiasis management

Multifactorial inhibition of Candida albicans by combinations of lactobacilli and probiotic Saccharomyces cerevisiae CNCM I-3856

Strategies against the opportunistic fungal pathogen Candida albicans based on probiotic microorganisms represent a promising alternative to traditional antifungals. Here, we investigated the effects of Lactobacillaceae isolates from fermented foods or the human vagina, alone or in combination with the probiotic yeast Saccharomyces cerevisiae CNCM I-3856, against C. albicans in vitro. Nine out of nineteen tested strains of Lactobacillaceae inhibited growth of C. albicans with inhibition zones of 1-3 mm in spot assays. Five out of nineteen lactobacilli tested as such or in combination with S. cerevisiae CNCM I-3856 also significantly inhibited C. albicans hyphae formation, including Limosilactobacillus fermentum LS4 and L. fermentum LS5 resulting in respectively 62% and 78% hyphae inhibition compared to the control. Thirteen of the tested nineteen lactobacilli aggregated with the yeast form of C. albicans, with Lactiplantibacillus carotarum AMBF275 showing the strongest aggregation. The aggregation was enhanced when lactobacilli were combined with S. cerevisiae CNCM I-3856. No significant antagonistic effects were observed between the tested lactobacilli and S. cerevisiae CNCM I-3856. The multifactorial activity of Lactobacillaceae strains alone or combined with the probiotic S. cerevisiae CNCM I-3856 against C. albicans without antagonistic effects between the beneficial strains, paves the way for developing consortium probiotics for in vivo applications.

Evaluation of the antifungal effect of plant extracts on oral Candidaspp. - a critical methodological analysis of the last decade

INTRODUCTION

In 2022, the World Health Organization published a report encouraging researchers to focus on Candida spp. to strengthen the global response to fungal oral infections and antifungal resistance. In the context of innovative research, it seems pertinent to investigate the antifungal potential of natural extracts of plants and the methodology involved in the recent reports. The aim of this systematic review is to identify the current state of in vitro research on the evaluation of the ability of plant extracts to inhibit Candida spp.

MATERIAL AND METHODS

A bibliographic search has been developed to on a 10-year period to identify which plant extracts have an antifungal effect on the Candida spp. found in the oral cavity.

RESULTS

A total of 20 papers were reviewed and fulfilled all the selection criteria and were included in the full data analysis.

DISCUSSION

Plants have been tested in a wide range of states - whole extracts, extraction of particular components such as flavonoids or polyphenols, or even using the plant to synthesize nanoparticles. Of forty-five plants tested, five of them did not show any effect against Candida spp., which weren't part of the same family. There is a wide range of plant that exhibit antifungal proprieties.

CONCLUSION

Many plants have been tested in a wide range of states - whole extracts, extraction of components such as flavonoids or polyphenols, or even using the plant to synthetize nanoparticles. The combination of plants, the addition of plants to a traditional antifungal and the interference with adhesion provided by some plants seem to be promising strategies. Nonetheless, on contrary to drugs, there is a critical lack of standardization on methodologies and protocols, which makes it difficult to compare data and, consequently, to conclude, beyond doubts, about the most promising plants to fight Candida spp. oral infections.

Exploring the Mechanistic Interplay between Gut Microbiota and Precocious Puberty: A Narrative Review

The gut microbiota has been implicated in the context of sexual maturation during puberty, with discernible differences in its composition before and after this critical developmental stage. Notably, there has been a global rise in the prevalence of precocious puberty in recent years, particularly among girls, where approximately 90% of central precocious puberty cases lack a clearly identifiable cause. While a link between precocious puberty and the gut microbiota has been observed, the precise causality and underlying mechanisms remain elusive. This narrative review aims to systematically elucidate the potential mechanisms that underlie the intricate relationship between the gut microbiota and precocious puberty. Potential avenues of exploration include investigating the impact of the gut microbiota on endocrine function, particularly in the regulation of hormones, such as gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Additionally, this review will delve into the intricate interplay between the gut microbiome, metabolism, and obesity, considering the known association between obesity and precocious puberty. This review will also explore how the microbiome's involvement in nutrient metabolism could impact precocious puberty. Finally, attention is given to the microbiota's ability to produce neurotransmitters and neuroactive compounds, potentially influencing the central nervous system components involved in regulating puberty. By exploring these mechanisms, this narrative review seeks to identify unexplored targets and emerging directions in understanding the role of the gut microbiome in relation to precocious puberty. The ultimate goal is to provide valuable insights for the development of non-invasive diagnostic methods and innovative therapeutic strategies for precocious puberty in the future, such as specific probiotic therapy.

Our current clinical understanding of Candida biofilms: where are we two decades on?

Clinically we have been aware of the concept of Candida biofilms for many decades, though perhaps without the formal designation. Just over 20 years ago the subject emerged on the back of progress made from the bacterial biofilms, and academic progress pace has continued to mirror the bacterial biofilm community, albeit at a decreased volume. It is apparent that Candida species have a considerable capacity to colonize surfaces and interfaces and form tenacious biofilm structures, either alone or in mixed species communities. From the oral cavity, to the respiratory and genitourinary tracts, wounds, or in and around a plethora of biomedical devices, the scope of these infections is vast. These are highly tolerant to antifungal therapies that has a measurable impact on clinical management. This review aims to provide a comprehensive overight of our current clinical understanding of where these biofilms cause infections, and we discuss existing and emerging antifungal therapies and strategies.

The impact of gene polymorphism and hepatic insufficiency on voriconazole dose adjustment in invasive fungal infection individuals

Voriconazole (VRZ) is a broad-spectrum antifungal medication widely used to treat invasive fungal infections (IFI). The administration dosage and blood concentration of VRZ are influenced by various factors, posing challenges for standardization and individualization of dose adjustments. On the one hand, VRZ is primarily metabolized by the liver, predominantly mediated by the cytochrome P450 (CYP) 2C19 enzyme. The genetic polymorphism of CYP2C19 significantly impacts the blood concentration of VRZ, particularly the trough concentration (Ctrough), thereby influencing the drug's efficacy and potentially causing adverse drug reactions (ADRs). Recent research has demonstrated that pharmacogenomics-based VRZ dose adjustments offer more accurate and individualized treatment strategies for individuals with hepatic insufficiency, with the possibility to enhance therapeutic outcomes and reduce ADRs. On the other hand, the security, pharmacokinetics, and dosing of VRZ in individuals with hepatic insufficiency remain unclear, making it challenging to attain optimal Ctrough in individuals with both hepatic insufficiency and IFI, resulting in suboptimal drug efficacy and severe ADRs. Therefore, when using VRZ to treat IFI, drug dosage adjustment based on individuals' genotypes and hepatic function is necessary. This review summarizes the research progress on the impact of genetic polymorphisms and hepatic insufficiency on VRZ dosage in IFI individuals, compares current international guidelines, elucidates the current application status of VRZ in individuals with hepatic insufficiency, and discusses the influence of CYP2C19, CYP3A4, CYP2C9, and ABCB1 genetic polymorphisms on VRZ dose adjustments and Ctrough at the pharmacogenomic level. Additionally, a comprehensive summary and analysis of existing studies' recommendations on VRZ dose adjustments based on CYP2C19 genetic polymorphisms and hepatic insufficiency are provided, offering a more comprehensive reference for dose selection and adjustments of VRZ in this patient population.

Use of probiotic lactobacilli in the treatment of vaginal infections: In vitro and in vivo investigations

The vaginal microbiome is a distinct component of the human microbiome that is colonized by a wide variety of microorganisms. Lactobacilli are the most frequently identified microorganisms in the healthy human vagina. These Gram-positive bacilli can acidify the vaginal microenvironment, inhibit the proliferation of other pathogenic microorganisms, and promote the maintenance of a eubiotic vaginal microbiome. However, a vaginal flora with a reduced proportion or abundance of lactobacilli is associated with various vaginal infections that have been linked to serious health consequences such as infertility, preterm birth, pelvic inflammatory disease, premature rupture of membranes, and miscarriage. Due to their “Generally Recognized as Safe” classification and critical role in vaginal health, probiotic lactobacilli have been widely used as an alternative or adjunct to traditional antibiotic therapy for the treatment of vaginal infections and restoration of the vaginal microbiome. This review focuses on the significant role of probiotic lactobacilli in the vaginal microenvironment and discusses the use of probiotic lactobacilli in the treatment of female vaginal infections in vitro and in vivo.

Acetate modulates the inhibitory effect of Lactobacillus gasseri against the pathogenic yeasts Candida albicans and Candida glabrata

The exploration of the interference prompted by commensal bacteria over fungal pathogens is an interesting alternative to develop new therapies. In this work we scrutinized how the presence of the poorly studied vaginal species Lactobacillus gasseri affects relevant pathophysiological traits of Candida albicans and Candida glabrata. L. gasseri was found to form mixed biofilms with C. albicans and C. glabrata resulting in pronounced death of the yeast cells, while bacterial viability was not affected. Reduced viability of the two yeasts was also observed upon co-cultivation with L. gasseri under planktonic conditions. Either in planktonic cultures or in biofilms, the anti-Candida effect of L. gasseri was augmented by acetate in a concentration-dependent manner. During planktonic co-cultivation the two Candida species counteracted the acidification prompted by L. gasseri thus impacting the balance between dissociated and undissociated organic acids. This feature couldn't be phenocopied in single-cultures of L. gasseri resulting in a broth enriched in acetic acid, while in the co-culture the non-toxic acetate prevailed. Altogether the results herein described advance the design of new anti-Candida therapies based on probiotics, in particular, those based on vaginal lactobacilli species, helping to reduce the significant burden that infections caused by Candida have today in human health.

Probiotic Properties of Chicken-Derived Highly Adherent Lactic Acid Bacteria and Inhibition of Enteropathogenic Bacteria in Caco-2 Cells

Lactic acid bacteria (LAB) as probiotic candidates have various beneficial functions, such as regulating gut microbiota, inhibiting intestinal pathogens, and improving gut immunity. The colonization of the intestine is a prerequisite for probiotic function. Therefore, it is necessary to screen the highly adherent LAB. In this study, the cell surface properties, such as hydrophobicity, auto-aggregation, co-aggregation, and adhesion abilities of the six chicken-derived LAB to Caco-2 cells were investigated. All six strains showed different hydrophobicity (21.18-95.27%), auto-aggregation (13.61-30.17%), co-aggregation with Escherichia coli ATCC 25922 (10.23-36.23%), and Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311 (11.71-39.35%), and adhesion to Caco-2 cells (8.57-26.37%). Pediococcus pentosaceus 2-5 and Lactobacillus reuteri L-3 were identified as the strains with strong adhesion abilities (26.37% and 21.57%, respectively). Moreover, these strains could survive in a gastric acid environment at pH 2, 3, and 4 for 3 h and in a bile salt environment at 0.1%, 0.2%, and 0.3% (w/v) concentration for 6 h. Furthermore, the cell-free supernatant of P. pentosaceus 2-5 and L. reuteri L-3 inhibited the growth of enteropathogenic bacteria and the strains inhibited the adhesion of these pathogens to Caco-2 cells. In this study, these results suggested that P. pentosaceus 2-5 and L. reuteri L-3, isolated from chicken intestines might be good probiotic candidates to be used as feed additives or delivery vehicles of biologically active substances.

Physiological and transcriptional profiling of surfactin exerted antifungal effect against Candida albicans

Given the risk of Candida albicans overgrowth in the gut, novel complementary therapies should be developed to reduce fungal dominancy. This study highlights the antifungal characteristics of a Bacillus subtilis-derived secondary metabolite, surfactin with high potential against C. albicans. Surfactin inhibited the growth of C. albicans following a 1-hour exposure, in addition to reduced adhesion and morphogenesis. Specifically, surfactin did not affect the level of reactive oxygen species but increased the level of reduced glutathione. Surprisingly, ethanol production was increased following 2 h of surfactin exposure. Surfactin treatment caused a significant reduction in intracellular iron, manganese and zinc content compared to control cells, whereas the level of copper was not affected. Alongside these physiological properties, surfactin also enhanced fluconazole efficacy. To gain detailed insights into the surfactin-related effects on C. albicans, genome-wide gene transcription analysis was performed. Surfactin treatment resulted in 1390 differentially expressed genes according to total transcriptome sequencing (RNA-Seq). Of these, 773 and 617 genes with at least a 1.5-fold increase or decrease in transcription, respectively, were selected for detailed investigation. Several genes involved in morphogenesis or related to metabolism (e.g., glycolysis, ethanol and fatty acid biosynthesis) were down-regulated. Moreover, surfactin decreased the expression of ERG1, ERG3, ERG9, ERG10 and ERG11 involved in ergosterol synthesis, whereas genes associated with ribosome biogenesis and iron metabolism and drug transport-related genes were up-regulated. Our data demonstrate that surfactin significantly influences the physiology and gene transcription of C. albicans, and could contribute to the development of a novel innovative complementary therapy.

Marine Compounds with Anti-Candida sp. Activity: A Promised “Land” for New Antifungals

Candida albicans is still the major yeast causing human fungal infections. Nevertheless, in the last decades, non-Candida albicans Candida species (NCACs) (e.g., Candida glabrata, Candida tropicalis, and Candida parapsilosis) have been increasingly linked to Candida sp. infections, mainly in immunocompromised and hospitalized patients. The escalade of antifungal resistance among Candida sp. demands broadly effective and cost-efficient therapeutic strategies to treat candidiasis. Marine environments have shown to be a rich source of a plethora of natural compounds with substantial antimicrobial bioactivities, even against resistant pathogens, such as Candida sp. This short review intends to briefly summarize the most recent marine compounds that have evidenced anti-Candida sp. activity. Here, we show that the number of compounds discovered in the last years with antifungal activity is growing. These drugs have a good potential to be used for the treatment of candidiasis, but disappointedly the reports have devoted a high focus on C. albicans, neglecting the NCACs, highlighting the need to perform outspreading studies in the near future.

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.

Prevalence and Antifungal Susceptibility Profile of Oral Candida spp. Isolates from a Hospital in Slovakia

Oral fungal infections are a worldwide healthcare problem. Although Candida albicans is still the most common yeast involved in the infections of oral cavity, non-Candida albicans Candida species (NCACs) have been highly related to these infections, particularly in older, immunosuppressed or patients with long exposure to antimicrobial drugs. The goal of this work was to perform a quick epidemiological and mycological study on the oral samples collected from a laboratory of a hospital in Slovakia, for 60 days. The samples’ identification was performed by Germ-tube formation test, CHROMID® Candida, Auxacolor 2, ID 32C automated method, and the antifungal susceptibility testing determined by E-test®. Results confirm that comparing with bacteria, yeasts still occur in the lower number, but there is a high rate of antifungal resistance (81.6%)—to, at least one drug—among the collected samples, particularly to azoles and 5′-FC, which is clinically noteworthy.

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.

Overview on the Prevalence of Fungal Infections, Immune Response, and Microbiome Role in COVID-19 Patients

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words "fungal infections COVID-19", between 2020-2021.

Lactobacillus reuteri BM53-1 Produces a Compound That Inhibits Sticky Glucan Synthesis by Streptococcus mutans

Cariogenic bacteria, such as Streptococcus (S.) mutans and S. sobrinus, produce insoluble and sticky glucans as a biofilm material. The present study demonstrates that a lactic acid bacterium (LAB) named BM53-1 produces a substance that inhibits the sticky glucan synthesis. The BM53-1 strain was isolated from a flower of Actinidia polygama and identified as Lactobacillus reuteri. The substance that inhibits sticky glucan synthesis does not exhibit antibacterial activity against S. mutans. The cariogenic S. mutans produces glucans under the control of three glucosyltransferase (GTF) enzymes, named GtfB, GtfC, and GtfD. Although GtfB and GtfC produce insoluble glucans, GtfD forms soluble glucans. Through quantitative reverse-transcriptional (qRT)-PCR analysis, it was revealed that the BM53-1-derived glucan-production inhibitor (GI) enhances the transcriptions of gtfB and gtfC genes 2- to 7-fold at the early stage of cultivation. However, that of gtfD was not enhanced in the presence of the GI, indicating that the glucan stickiness produced by S. mutans was significantly weaker in the presence of the GI. Our result demonstrates that Lb. reuteri BM53-1 is useful to prevent dental caries.