Topical application of probiotics in skin: adhesion, antimicrobial and antibiofilm in vitro assays

Mechanisms of medicinal, pharmaceutical, and immunomodulatory action of probiotics bacteria and their secondary metabolites against disease management: an overview

Probiotics or bacteriotherapy is today's hot issue for public entities (Food and Agriculture Organization, and World Health Organization) as well as health and food industries since Metchnikoff and his colleagues hypothesized the correlation between probiotic consumption and human's health. They contribute to the newest and highly efficient arena of promising biotherapeutics. These are usually attractive in biomedical applications such as gut-related diseases like irritable bowel disease, diarrhea, gastrointestinal disorders, fungal infections, various allergies, parasitic and bacterial infections, viral diseases, and intestinal inflammation, and are also worth immunomodulation. The useful impact of probiotics is not limited to gut-related diseases alone. Still, these have proven benefits in various acute and chronic infectious diseases, like cancer, human immunodeficiency virus (HIV) diseases, and high serum cholesterol. Recently, different researchers have paid special attention to investigating biomedical applications of probiotics, but consolidated data regarding bacteriotherapy with a detailed mechanistically applied approach is scarce and controversial. The present article reviews the bio-interface of probiotic strains, mainly (i) why the demand for probiotics?, (ii) the current status of probiotics, (iii) an alternative to antibiotics, (iv) the potential applications towards disease management, (v) probiotics and industrialization, and (vi) futuristic approach.

Restraining Staphylococcus aureus Virulence Factors and Quorum Sensing through Lactic Acid Bacteria Supernatant Extracts

The escalating prevalence of antibiotic-resistant bacteria poses a grave threat to human health, necessitating the exploration of novel alternatives to conventional antibiotics. This study investigated the impact of extracts derived from the supernatant of four lactic acid bacteria strains on factors contributing to the pathogenicity of three Staphylococcus aureus strains. The study evaluated the influence of lactic acid bacteria supernatant extracts on the growth, biofilm biomass formation, biofilm metabolic activity, and biofilm integrity of the S. aureus strains. Additionally, the impact on virulence factors (hemolysin and coagulase) was examined. Gas chromatography coupled with mass spectrometry was used to identify the bioactive compounds in the extracts, while molecular docking analyses explored potential interactions. Predominantly, the extracts contain eight 2,5-diketopiperazines, which are cyclic forms of peptides. The extracts demonstrated inhibitory effects on biofilm formation, the ability to disrupt mature biofilms, and reduce the biofilm cell metabolic activity of the S. aureus strains. Furthermore, they exhibited the ability to inhibit α-hemolysin production and reduce coagulase activity. An in silico docking analysis reveals promising interactions between 2,5-diketopiperazines and key proteins (SarA and AgrA) in S. aureus, confirming their antivirulence and antibiofilm activities. These findings suggest that 2,5-diketopiperazines could serve as a promising lead compound in the fight against antibiotic-resistant S. aureus.

The role of the skin microbiome in wound healing

The efficient management of skin wounds for rapid and scarless healing represents a major clinical unmet need. Nonhealing skin wounds and undesired scar formation impair quality of life and result in high healthcare expenditure worldwide. The skin-colonizing microbiota contributes to maintaining an intact skin barrier in homeostasis, but it also participates in the pathogenesis of many skin disorders, including aberrant wound healing, in many respects. This review focuses on the composition of the skin microbiome in cutaneous wounds of different types (i.e. acute and chronic) and with different outcomes (i.e. nonhealing and hypertrophic scarring), mainly based on next-generation sequencing analyses; furthermore, we discuss the mechanistic insights into host-microbe and microbe-microbe interactions during wound healing. Finally, we highlight potential therapeutic strategies that target the skin microbiome to improve healing outcomes.

Anti-bacterial, anti-biofilm and anti-quorum sensing activities of honey: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Man has used honey to treat diseases since ancient times, perhaps even before the history of medicine itself. Several civilizations have utilized natural honey as a functional and therapeutic food to ward off infections. Recently, researchers worldwide have been focusing on the antibacterial effects of natural honey against antibiotic-resistant bacteria.

AIM OF THE STUDY

This review aims to summarize research on the use of honey properties and constituents with their anti-bacterial, anti-biofilm, and anti-quorum sensing mechanisms of action. Further, honey's bacterial products, including probiotic organisms and antibacterial agents which are produced to curb the growth of other competitor microorganisms is addressed.

MATERIALS AND METHODS

In this review, we have provided a comprehensive overview of the antibacterial, anti-biofilm, and anti-quorum sensing activities of honey and their mechanisms of action. Furthermore, the review addressed the effects of antibacterial agents of honey from bacterial origin. Relevant information on the antibacterial activity of honey was obtained from scientific online databases such as Web of Science, Google Scholar, ScienceDirect, and PubMed.

RESULTS

Honey's antibacterial, anti-biofilm, and anti-quorum sensing activities are mostly attributed to four key components: hydrogen peroxide, methylglyoxal, bee defensin-1, and phenolic compounds. The performance of bacteria can be altered by honey components, which impact their cell cycle and cell morphology. To the best of our knowledge, this is the first review that specifically summarizes every phenolic compound identified in honey along with their potential antibacterial mechanisms of action. Furthermore, certain strains of beneficial lactic acid bacteria such as Bifidobacterium, Fructobacillus, and Lactobacillaceae, as well as Bacillus species can survive and even grow in honey, making it a potential delivery system for these agents.

CONCLUSION

Honey could be regarded as one of the best complementary and alternative medicines. The data presented in this review will enhance our knowledge of some of honey's therapeutic properties as well as its antibacterial activities.

The potential of Bacillus and Enterococcus probiotic strains to combat helicobacter pylori attachment to the biotic and abiotic surfaces

The prevention of biofilm formation plays a pivotal role in managing Helicobacter pylori inside the body and the environment. This study showed in vitro potentials of two recently isolated probiotic strains, Bacillus sp. 1630F and Enterococcus sp. 7C37, to form biofilm and combat H. pylori attachment to the abiotic and biotic surfaces. Lactobacillus casei and Bifidobacterium bifidum were used as the reference probiotics. The biofilm rates were the highest in the solid-liquid interface for Lactobacillus and Bifidobacterium and the air-liquid interface for Bacillus and Enterococcus. The highest tolerances to the environmental conditions were observed during the biofilm formations of Enterococcus and Bifidobacterium (pH), Enterococcus and Bacillus (bile), and Bifidobacterium and Lactobacillus (NaCl) on the polystyrene and glass substratum, respectively. Biofilms occurred more quickly by Bacillus and Enterococcus strains than reference strains on the polystyrene and glass substratum, respectively. Enterococcus (competition) and Bacillus (exclusion) achieved the most inhibition of H. pylori biofilm formations on the polystyrene and AGS cells, respectively. Expression of luxS was promoted by Bacillus (exclusion, 3.2 fold) and Enterococcus (competition, 2.0 fold). Expression of ropD was decreased when H. pylori biofilm was excluded by Bacillus (0.4 fold) and Enterococcus (0.2 fold) cells. This study demonstrated the ability of Bacillus and Enterococcus probiotic bacteria to form biofilm and combat H. pylori biofilm formation.

Applications of Probiotic Constituents in Cosmetics

Over the past few decades, research on the benefits of beneficial microorganisms on skin health has expanded and attracted a lot of attention. Today, a wide range of probiotic products are becoming available. With their extensive component profiles and varied physiological effects, probiotics, as well as extracts of them, have a significant impact on cosmetics. However, the present boom in consumer interest in alternatives has broadened the probiotic industry's research and development frontiers. Considering the foregoing, it should come as no surprise that probiotics are highly valued for their proven anti-aging, skin whitening, anti-inflammatory, and photoprotective effects. This review aims to compile information on probiotics' properties, their extracts, and preparations used in cosmetics. It also further summarizes research and applications on probiotic fermentation to promote the use of probiotic fermentation products in cosmetics. Notably, this review also adds information on particular properties and mechanisms of action of probiotics, which fills a gap in the research and application of probiotics in skin treatment and care. Their antioxidant and anti-aging qualities have received particular consideration. This review provides a new basis for the broad application of probiotics in cosmetics.

Biodiversity of Skin Microbiota as an Important Biomarker for Wound Healing

Cutaneous wound healing is a natural and complex repair process that is implicated within four stages. However, microorganisms (e.g., bacteria) can easily penetrate through the skin tissue from the wound bed, which may lead to disbalance in the skin microbiota. Although commensal and pathogenic bacteria are in equilibrium in normal skin, their imbalance in the wound area can cause the delay or impairment of cutaneous wounds. Moreover, skin microbiota is in constant crosstalk with the immune system and epithelial cells, which has significance for the healing of a wound. Therefore, understanding the major bacteria species in the cutaneous wound as well as their communication with the immune system has gained prominence in a way that allows for the emergence of a new perspective for wound healing. In this review, the major bacteria isolated from skin wounds, the role of the crosstalk between the cutaneous microbiome and immune system to heal wounds, the identification techniques of these bacteria populations, and the applied therapies to manipulate the skin microbiota are investigated.

Promising biotherapeutic prospects of different probiotics and their derived postbiotic metabolites: in-vitro and histopathological investigation

BACKGROUND

Probiotics and their derived postbiotics, as cell-free supernatants (CFS), are gaining a solid reputation owing to their prodigious health-promoting effects. Probiotics play a valuable role in the alleviation of various diseases among which are infectious diseases and inflammatory disorders. In this study, three probiotic strains, Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Pediococcus acidilactici, were isolated from marketed dietary supplements. The antimicrobial activity of the isolated probiotic strains as well as their CFS was investigated. The neutralized CFS of the isolated probiotics were tested for their antibiofilm potential. The anti-inflammatory activity of the isolated Lactobacillus spp., together with their CFS, was studied in the carrageenan-induced rat paw edema model in male Wistar rats. To the best of our knowledge, such a model was not previously experimented to evaluate the anti-inflammatory activity of the CFS of probiotics. The histopathological investigation was implemented to assess the anti-inflammatory prospect of the isolated L. plantarum and L. rhamnosus strains as well as their CFS.

RESULTS

The whole viable probiotics and their CFS showed variable growth inhibition of the tested indicator strains using the agar overlay method and the microtiter plate assay, respectively. When tested for virulence factors, the probiotic strains were non-hemolytic lacking both deoxyribonuclease and gelatinase enzymes. However, five antibiotic resistance genes, blaZ, ermB, aac(6')- aph(2"), aph(3'')-III, and vanX, were detected in all isolates. The neutralized CFS of the isolated probiotics exhibited an antibiofilm effect as assessed by the crystal violet assay. This effect was manifested by hindering the biofilm formation of the tested Staphylococcus aureus and Pseudomonas aeruginosa clinical isolates in addition to P. aeruginosa PAO1 strain. Generally, the cell cultures of the two tested probiotics moderately suppressed the acute inflammation induced by carrageenan compared to indomethacin. Additionally, the studied CFS relatively reduced the inflammatory changes compared to the inflammation control group but less than that observed in the case of the probiotic cultures treated groups.

CONCLUSIONS

The tested probiotics, along with their CFS, showed promising antimicrobial and anti-inflammatory activities. Thus, their safety and their potential use as biotherapeutics for bacterial infections and inflammatory conditions are worthy of further investigation.

Isolation of lectin from Musa acuminata for its antibiofilm potential against Methicillin-resistant Staphylococcus aureus and its synergistic effect with Enterococcus species

Methicillin resistant Staphylococcus aureus (MRSA) is an emerging pathogen posing a considerable burden on the healthcare system due to its involvement in skin and soft tissue infections (SSTIs). Lectins are carbohydrate binding proteins found ubiquitously in animals, plants and microorganisms. Extraction and isolation of proteins from Musa acuminata were performed by using Affinity chromatography with Sephadex G 75 to determine antibiofilm activity against MRSA. Enterococcus strains obtained from dairy products, beans and vegetables were also screened for its potential to inhibit growth and biofilm formation of MRSA by using 96 well microtiter plates. Synergistic effect of cell free supernatant of Enterococcus with proteins from ripe banana were also tested. BanLec was successfully isolated and appeared as 15 KDa band after SDS-PAGE (15%) while multiple bands of unbound protein fractions were observed. The unbound fractions showed inhibition of planktonic cells and biofilm but BanLec exhibited no significant effect. The CFS of Enterococcus faecium (LCM002), Enterococcus lactis (LCM003) and Enterococcus durans (LCM004 and LCM005) displayed antagonistic effects against pathogen. The synergistic effect of CFS from E. lactis (LCM003) and unbound proteins showed inhibition of biofilm and pathogenic growth. This study demonstrates the use of Enterococcus species and plant proteins against pathogens and results suggested that it can inhibit the growth of resistant strains of Staphylococcus aureus and their synergistic effect has opened new ways to tackle emerging resistance. Furthermore, after assessment of Enterococcus as probiotics, this could be used in food industries as well as in treatment of severe skin 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.

Development and Characterization of Hydroxyethyl Cellulose-Based Gels Containing Lactobacilli Strains: Evaluation of Antimicrobial Effects in In Vitro and Ex Vivo Models

This study aimed to develop a hydroxyethyl cellulose-based topical formulation containing probiotics and to evaluate its antimicrobial action using in vivo and ex vivo models. Initially, the antagonistic effects of Lacticaseibacillus rhamnosus ATCC 10863, Limosilactobacillus fermentum ATCC 23271, Lactiplantibacillus plantarum ATCC 8014 and Lactiplantibacillus plantarum LP-G18-A11 were analyzed against Enterococcus faecalis ATCC 29212, Klebsiella pneumoniae ATCC 700603, Staphylococcus aureus ATCC 27853 and Pseudomonas aeruginosa ATCC 2785. The best action was seen for L. plantarum LP-G18-A11, which presented high inhibition against S. aureus and P. aeruginosa. Then, lactobacilli strains were incorporated into hydroxyethyl cellulose-based gels (natrosol); however, only the LP-G18-A11-incorporated gels (5% and 3%) showed antimicrobial effects. The LP-G18-A11 gel (5%) maintained its antimicrobial effects and viability up to 14 and 90 days at 25 °C and 4 °C, respectively. In the ex vivo assay using porcine skin, the LP-G18-A11 gel (5%) significantly reduced the skin loads of S. aureus and P. aeruginosa after 24 h, while only P. aeruginosa was reduced after 72 h. Moreover, the LP-G18-A11 gel (5%) showed stability in the preliminary and accelerated assays. Taken together, the results show the antimicrobial potential of L. plantarum LP-G18-A11, which may be applied in the development of new dressings for the treatment of infected wounds.

Enhanced antimicrobial activity of lactic acid bacteria through genome shuffling and genetic variability among shuffled strains

In this investigation, lactic acid bacteria (LAB) isolated from milk were tested for their antibacterial properties and improved the antimicrobial activity of these isolates using genome shuffling. A total of sixty-one isolates were found in eleven samples, which were then tested using the agar diffusion method for their antibacterial activity against Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. Thirty-one strains exhibited antibacterial activity against at least one of the tested pathogens, with an inhibitory zone's diameter varying between 15.0 and 24.0 mm. Two isolates that showed the highest antimicrobial activity were identified as Lactobacillus plantarum CIP 103151 and Lactobacillus plantarum JCM 1149 according to 16S rRNA analysis. In the present study, applying genome shuffling approach significantly enhanced the antibacterial activity of L. plantarum. The initial populations were obtained via ultraviolet irradiation and were treated using the protoplast fusion method. The ideal condition for the production of protoplasts was 15 mg/ml of lysozyme and 10 μg/ml of mutanolysin. After two rounds of fusion, ten recombinants exhibited a significant increase in the inhibition zones versus S. aureus, S. typhimurium, P. aeruginosa, and E. coli, reaching up to 1.34, 1.31, 1.37, and 1.37-fold increase in inhibitory zone respectively. Random Amplified Polymorphic DNA results showed clear differences in DNA banding patterns among the wild strain of L. plantarum CIP 103151 and the three selected shuffled strains using primers 1283 & OPA09. On the other hand, no change was obtained using primers OPD03 neither among the wild strain and the three recombinant strains nor among the three shuffled strains.

Lactobacilli and Their Probiotic Effects in the Vagina of Reproductive Age Women

In the present narrative review, the probiotic effects of vaginal Lactobacillus spp. are described in detail, covering the importance of the differential production of lactic acid, the lactic acid D/L isoforms, the questionable in vivo effect of hydrogen peroxide, as well as bacteriocins and other core proteins produced by vaginal Lactobacillus spp. Moreover, the microbe–host interaction is explained with emphasis on the vaginal mucosa. To understand the crucial role of Lactobacillus spp. dominance in the vaginal microbiota, different dysbiotic states of the vagina are explained including bacterial vaginosis and aerobic vaginitis. Finally, this review takes on the therapeutic aspect of live lactobacilli in the context of bacterial vaginosis. Until recently, there was very low-quality evidence to suggest that any probiotic might aid in reducing vaginal infections or dysbiosis. Therefore, clinical usage or over the counter usage of probiotics was not recommended. However, recent progress has been made, moving from probiotics that are typically regulated as food supplements to so-called live biotherapeutic products that are regulated as medical drugs. Thus, recently, a phase 2b trial using a Lactobacillus crispatus strain as a therapeutic add-on to standard metronidazole showed significant reduction in the recurrence of bacterial vaginosis by 12 weeks compared to placebo. This may constitute evidence for a brighter future where the therapeutic use of lactobacilli can be harnessed to improve women’s health.

Improved treatment of vulvovaginal candidiasis with Clotrimazole plus probiotic Lacidophilin Vaginal Capsules: A prospective, real-world study

BACKGROUND

Clotrimazole has long been used to treat vulvovaginal candidiasis (VVC), yet the antibiotic resistance, adverse effects and recurrences still bring about a great challenge for the clinicians. To explore the effect of probiotic Lacidophilin Vaginal Capsules plus Clotrimazole Vaginal Tablets (500mg) in the treatment of uncomplicated VVC, a self-controlled real-world study was conducted.

METHODS

Twenty-seven women with a normal vaginal flora and 15 women with uncomplicated VVC were recruited. The patients were treated with the single dose of Clotrimazole Vaginal Tablets (500mg) supplemented with 2 Lacidophilin Vaginal Capsules for the following 7 days. The patients were prospectively examined 4 times and the time points were at m0 (the first visit), m1 (8-10 days after the first visit), m2 (30 days after the second visit) and m3 (30 days after the third visit). However, women in the healthy normal control group were examined just once at the first visit. The obtained vaginal secretions were examined by high-throughput sequencing.

RESULTS

The mean age in healthy control group and case group was 28.63 ± 5.40y and 27.67 ± 3.33y, respectively. Finally, 46.67% (7/15) of patients were cured at the second visit, 61.54% (8/13) were cured at the third visit and eventually 72.73% (8/11) were cured. A total of 81 samples were sequenced, generating 1668 operation taxonomy units among all the samples. The bacterial composition of women in the healthy control group was exceedingly abundant and dominated by Lactobacillus, especially by Lactobacillus. crispatus, and followed by Lactobacillus. iners, Lactobacillus. jensenii and Gardneralla. On the contrary, the bacterial composition of women with VVC was relatively few and dominated by Lactobacillus. iners. During the process of treatment, the bacterial abundance of VVC patients was increased gradually. At the final visit, the abundance of vaginal flora was augmented further with the dominant bacteria being Lactobacillus. crispatus, followed by Lactobacillus. iners.

CONCLUSION

Clotrimazole Vaginal Tablets plus probiotic Lacidophilin Vaginal Capsules could improve the effect in treating uncomplicated VVC. This improved effect was achieved perhaps through improving the composition of vaginal flora and restoring vaginal microecology.

The Antimicrobial Effect of Various Single-Strain and Multi-Strain Probiotics, Dietary Supplements or Other Beneficial Microbes against Common Clinical Wound Pathogens

The skin is the largest organ in the human body and is colonized by a diverse microbiota that works in harmony to protect the skin. However, when skin damage occurs, the skin microbiota is also disrupted, and pathogens can invade the wound and cause infection. Probiotics or other beneficial microbes and their metabolites are one possible alternative treatment for combating skin pathogens via their antimicrobial effectiveness. The objective of our study was to evaluate the antimicrobial effect of seven multi-strain dietary supplements and eleven single-strain microbes that contain probiotics against 15 clinical wound pathogens using the agar spot assay, co-culturing assay, and agar well diffusion assay. We also conducted genera-specific and species-specific molecular methods to detect the DNA in the dietary supplements and single-strain beneficial microbes. We found that the multi-strain dietary supplements exhibited a statistically significant higher antagonistic effect against the challenge wound pathogens than the single-strain microbes and that lactobacilli-containing dietary supplements and single-strain microbes were significantly more efficient than the selected propionibacteria and bacilli. Differences in results between methods were also observed, possibly due to different mechanisms of action. Individual pathogens were susceptible to different dietary supplements or single-strain microbes. Perhaps an individual approach such as a 'probiogram' could be a possibility in the future as a method to find the most efficient targeted probiotic strains, cell-free supernatants, or neutralized cell-free supernatants that have the highest antagonistic effect against individual clinical wound pathogens.

Advances in characterization of probiotics and challenges in industrial application

An unbalanced diet and poor lifestyle are common reasons for numerous health complications in humans. Probiotics are known to provide substantial benefits to human health by producing several bioactive compounds, vitamins, short-chain fatty acids and short peptides. Diets that contain probiotics are limited to curd, yoghurt, kefir, kimchi, etc. However, exploring the identification of more potential probiotics and enhancing their commercial application to improve the nutritional quality would be a significant step to utilizing the maximum benefits. The complex evolution patterns among the probiotics are the hurdles in their characterization and adequate application in the industries and dairy products. This article has mainly discussed the molecular methods of characterization that are based on the analysis of ribosomal RNA, whole genome, and protein markers and profiles. It also has critically emphasized the emerging challenges in industrial applications of probiotics.

Probiotic Adhesion to Skin Keratinocytes and Underlying Mechanisms

Simple Summary

The use of probiotics to ameliorate skin conditions has been suggested. This is based in the fact that they compete with pathogenic bacteria for adhesion sites, thereby displacing unwanted microorganisms. Lacticaseibacillus rhamnosus was able to adhere effectively to keratinocytes decreasing the number of adherent pathogenic bacteria. In the presence of pathogens all tested probiotics decreased invasion by S. aureus, one of the most relevant skin pathogens. Ex vivo models also showed wound healing capacity of L. rhamnosus with a concomitant decrease in the viable numbers of S. aureus, suggesting it is a good candidate as a co-adjuvant in the treatment of skin infections by this pathogen.

Abstract

The effects of probiotics on the skin are not yet well understood. Their topical application and benefits derived thereafter have recently been investigated. Improvements in different skin disorders such as atopic dermatitis, acne, eczema, and psoriasis after their use have, however, been reported. One of the mechanisms through which such benefits are documented is by inhibiting colonization by skin pathogens. Bacterial adhesion is the first step for colonization to occur; therefore, to avoid pathogenic colonization, inhibiting adhesion is crucial. In this study, invasion and adhesion studies have been carried out using keratinocytes. These showed that Escherichia coli is not able to invade skin keratinocytes, but adhered to them. Lacticaseibacillus rhamnosus and Propioniferax innocua decreased the viable counts of the three pathogens under study. L. rhamnosus significantly inhibited S. aureus adhesion. P. innocua did not inhibit pathogenic bacteria adhesion, but when added simultaneously with S. aureus (competition assay) a significant adhesion reduction (1.12 ± 0.14 log₁₀CFU/mL) was observed. Probiotic bacteria seem to use carbohydrates to adhere to the keratinocytes, while S. aureus uses proteins. Lacticaseibacillus rhamnosus showed promising results in pathogen inhibition in both in vitro and ex vivo experiments and can potentially be used as a reinforcement of conventional therapies for skin dysbiosis.

Current Trends in the Production of Probiotic Formulations

Preparations containing probiotic strains of bacteria have a beneficial effect on human and animal health. The benefits of probiotics translate into an increased interest in techniques for the preservation of microorganisms. This review compares different drying methods and their improvements, with specific reference to processing conditions, microorganisms, and protective substances. It also highlights some factors that may influence the quality and stability of the final probiotic preparations, including thermal, osmotic, oxidative, and acidic stresses, as well as dehydration and shear forces. Processing and storage result in the loss of viability and stability in probiotic formulations. Herein, the addition of protective substances, the optimization of process parameters, and the adaptation of cells to stress factors before drying are described as countermeasures to these challenges. The latest trends and developments in the fields of drying technologies and probiotic production are also discussed. These developments include novel application methods, controlled release, the use of food matrices, and the use of analytical methods to determine the viability of probiotic bacteria.

Acne, Microbiome, and Probiotics: The Gut–Skin Axis

The objective of this narrative review was to check the influence of the human microbiota in the pathogenesis of acne and how the treatment with probiotics as adjuvant or alternative therapy affects the evolution of acne vulgaris. Acne is a chronic inflammatory skin disease involving the pilosebaceous units. The pathogenesis of acne is complex and multifactorial involving genetic, metabolic, and hormonal factors in which both skin and gut microbiota are implicated. Numerous studies have shown the bidirectionality between the intestinal microbiota and skin homeostasis, a communication mainly established by modifying the immune system. Increased data on the mechanisms of action regarding the relevance of Cutibacterium acnes, as well as the importance of the gut–skin axis, are becoming known. Diverse and varied in vitro studies have shown the potential beneficial effects of probiotics in this context. Clinical trials with both topical and oral probiotics are scarce, although they have shown positive results, especially with oral probiotics through the modulation of the intestinal microbiota, generating an anti-inflammatory response and restoring intestinal integrity, or through metabolic pathways involving insulin-like growth factor I (IGF-1). Given the aggressiveness of some standard acne treatments, probiotics should continue to be investigated as an alternative or adjuvant therapy.

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.

Probiotics, Their Extracellular Vesicles and Infectious Diseases

Probiotics have been shown to be effective against infectious diseases in clinical trials, with either intestinal or extraintestinal health benefits. Even though probiotic effects are strain-specific, some "widespread effects" include: pathogen inhibition, enhancement of barrier integrity and regulation of immune responses. The mechanisms involved in the health benefits of probiotics are not completely understood, but these effects can be mediated, at least in part, by probiotic-derived extracellular vesicles (EVs). However, to date, there are no clinical trials examining probiotic-derived EVs health benefits against infectious diseases. There is still a long way to go to bridge the gap between basic research and clinical practice. This review attempts to summarize the current knowledge about EVs released by probiotic bacteria to understand their possible role in the prevention and/or treatment of infectious diseases. A better understanding of the mechanisms whereby EVs package their cargo and the process involved in communication with host cells (inter-kingdom communication), would allow further advances in this field. In addition, we comment on the potential use and missing knowledge of EVs as therapeutic agents (postbiotics) against infectious diseases. Future research on probiotic-derived EVs is needed to open new avenues for the encapsulation of bioactives inside EVs from GRAS (Generally Regarded as Safe) bacteria. This could be a scientific novelty with applications in functional foods and pharmaceutical industries.

Topical Probiotics: More Than a Skin Deep

Skin, an exterior interface of the human body is home to commensal microbiota and also acts a physical barrier that protects from invasion of foreign pathogenic microorganisms. In recent years, interest has significantly expanded beyond the gut microbiome to include the skin microbiome and its influence in managing several skin disorders. Probiotics play a major role in maintaining human health and disease prevention. Topical probiotics have demonstrated beneficial effects for the treatment of certain inflammatory skin diseases such as acne, rosacea, psoriasis etc., and also found to have a promising role in wound healing. In this review, we discuss recent insights into applications of topical probiotics and their influence on health and diseases of the skin. Patents, commercially available topical probiotics, and novel probiotic impregnated fabrics have been emphasized. A thorough understanding of the relationship between probiotics and the skin microbiome is important for designing novel therapeutic approaches in using topical probiotics.

The role of microbiota-derived postbiotic mediators on biofilm formation and quorum sensing-mediated virulence of Streptococcus mutans: A perspective on preventing dental caries

Dental caries is not only one of the most prevalent diseases worldwide, but also a public health problem, undoubtedly. Among the various types of cariogenic bacteria, Streptococcus mutans is considered to be the major etiological pathogen of dental caries. The present study aimed to assess the influence of microbiota-derived postbiotic mediators (PMs) on the pathogenesis of dental caries. Within this aim, the antibacterial (agar diffusion method) and antibiofilm (crystal violet assay) characteristics of PMs derived from Lactiplantibacillus plantarum EIR/IF-1, Lactiplantibacillus curvatus EIR/DG-1, and Lactiplantibacillus curvatus EIR/BG-2 against S. mutans (ATCC 25175) were analyzed. According to the results, PM of the strain EIR/IF-1, isolated from infant feces showed the highest inhibitory effect (pH-dependent). Besides, sub-MIC doses of all PMs eliminated the biofilm formation following the co-incubation and pre-treatment assays. The reduction of cell viability and notable changes in biofilm formation was also confirmed both on glass coverslips and ex vivo human tooth surfaces by confocal laser scanning microscopy and scanning electron microscopy. Moreover, sub-MIC values of PMs down-regulated the expression of gtfC, comA, and comX, without any significant growth inhibition. Organic acids, fatty acids, and vitamins in PMs were also reported. Overall, these findings indicated the possible preventive roles of microbiota-derived PMs for the pathogenesis of dental caries.

Advances in Microbiome-Derived Solutions and Methodologies Are Founding a New Era in Skin Health and Care

The microbiome, as a community of microorganisms and their structural elements, genomes, metabolites/signal molecules, has been shown to play an important role in human health, with significant beneficial applications for gut health. Skin microbiome has emerged as a new field with high potential to develop disruptive solutions to manage skin health and disease. Despite an incomplete toolbox for skin microbiome analyses, much progress has been made towards functional dissection of microbiomes and host-microbiome interactions. A standardized and robust investigation of the skin microbiome is necessary to provide accurate microbial information and set the base for a successful translation of innovations in the dermo-cosmetic field. This review provides an overview of how the landscape of skin microbiome research has evolved from method development (multi-omics/data-based analytical approaches) to the discovery and development of novel microbiome-derived ingredients. Moreover, it provides a summary of the latest findings on interactions between the microbiomes (gut and skin) and skin health/disease. Solutions derived from these two paths are used to develop novel microbiome-based ingredients or solutions acting on skin homeostasis are proposed. The most promising skin and gut-derived microbiome interventional strategies are presented, along with regulatory, safety, industrial, and technical challenges related to a successful translation of these microbiome-based concepts/technologies in the dermo-cosmetic industry.

Application and mechanism of probiotics in skin care: A review

BACKGROUND

Skin problems have been the focus of attention in recent years. Skin aging, wrinkles, pigmentation, dryness has been a problem that makes people feel troubled. Researchers have been devoted to find ways to solve these skin problems. Micro-ecological skin care is a popular concept these days, and improving skin health through the use of probiotics is a hot topic of discussion.

OBJECTIVE

Many experimental studies have shown that probiotics have a good effect on improving skin problems. This paper aims to comprehensively review the application and mechanism of probiotics in skin care and provide theoretical basis for the application of probiotics in skin care.

METHODS

Literatures in this review were searched in PubMed, China National Knowledge Infrastructure (CNKI), Web of Science, and Science Direct.

RESULTS

Probiotics have potent effects on skin whitening, moisturizing, anti-aging, anti-wrinkle and removing body odor.

CONCLUSIONS

The effects of probiotics on skin whitening, skin moisturizing, anti-aging, improving skin wrinkles and removing body odor were reviewed, which provided a new basis for the extensive application of probiotics in skin care.

Vitreoscilla filiformis Extract for Topical Skin Care: A Review

The term probiotic has been defined by experts as live microorganisms, which when administered in adequate amounts, confer a health benefit on the host. Probiotics are, thus, by definition, live microorganisms, and the viability of probiotics is a prerequisite for certain benefits, such as the release of metabolites at the site or adhesion properties, for example. However, some semi-active or non-replicative bacterial preparations may retain a similar activity to the live forms. On cosmetic, lysates or fractions are generally used. Topically applied Vitreoscilla filiformis extract has shown to have some similar biological activity of probiotics in the gut, for example, regulating immunity by optimisation of regulatory cell function, protecting against infection, and helping skin barrier function for better recovery and resistance. Due to their mode of action and efficacy, V. filiformis extract (lysate including membrane and cytosol) may be considered as non-replicative probiotic fractions, and this review article presents all its properties.

A combination of Vitreoscilla filiformis extract and Vichy volcanic mineralizing water strengthens the skin defenses and skin barrier

Probiotics are live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host. Semiactive, non-replicating bacteria or extracts used in dermocosmetics have interesting properties for skin quality. Vitreoscilla filiformis is cultured by a fermentation process to obtain an extract. It is considered as a probiotic fraction and topical application of this extract has shown activity to strengthen the skin physical barrier function and maintain good homeostasis of skin defenses. Vichy volcanic mineralizing water (VVMW) is a pure, highly mineralized water that has been shown to strengthen the skin against exposome aggressions. This manuscript reviews properties of probiotic fractions used in skin care, especially studies on an extract of V. filiformis grown in a medium containing VVMW (VfeV) and evaluated in combination with VVMW. Skin barrier function: In normal human epidermal keratinocyte cultures, the combination of 10% VVMW and 0.002% VfeV significantly increased transglutaminase, filaggrin, involucrin, claudin-1, and zonula occludens-1 in comparison with the controls. Antimicrobial peptide defenses: The combination of 16.7% VVMW and 0.1% VfeV increased the expression of β-defensin-4A and S100A7. Skin immune defense functions: In lipopolysaccharide-stimulated peripheral blood mononuclear cells, the combination of 16.7% VVMW and 0.1% VfeV down-regulated IL-8, TNF-α, IL-12/IL-23p40, and increased IL10 and IL-10/IL-12 ratio compared to the control. Additionally, the combination of 79% VVMW plus 5% VfeV protected Langerhans cells in skin explants exposed to ultraviolet radiation. In conclusion, the combination of VfeV plus VVMW has properties to strengthen the skin barrier by stimulating skin differentiation and tight junctions, biochemical defenses by stimulating antimicrobial peptides, and cellular immune defenses by increasing the IL-10/IL-12 ratio and by protecting Langerhans cells challenged by ultraviolet radiation.

Bioprospecting Antimicrobials from Lactiplantibacillus plantarum: Key Factors Underlying Its Probiotic Action

Lactiplantibacillus plantarum (L. plantarum) is a well-studied and versatile species of lactobacilli. It is found in several niches, including human mucosal surfaces, and it is largely employed in the food industry and boasts a millenary tradition of safe use, sharing a long-lasting relationship with humans. L. plantarum is generally recognised as safe and exhibits a strong probiotic character, so that several strains are commercialised as health-promoting supplements and functional food products. For these reasons, L. plantarum represents a valuable model to gain insight into the nature and mechanisms of antimicrobials as key factors underlying the probiotic action of health-promoting microbes. Probiotic antimicrobials can inhibit the growth of pathogens in the gut ensuring the intestinal homeostasis and contributing to the host health. Furthermore, they may be attractive alternatives to conventional antibiotics, holding potential in several biomedical applications. The aim of this review is to investigate the most relevant papers published in the last ten years, bioprospecting the antimicrobial activity of characterised probiotic L. plantarum strains. Specifically, it focuses on the different chemical nature, the action spectra and the mechanisms underlying the bioactivity of their antibacterial and antiviral agents. Emerging trends in postbiotics, some in vivo applications of L. plantarum antimicrobials, including strengths and limitations of their therapeutic potential, are addressed and discussed.

Effects of Probiotics in the Management of Infected Chronic Wounds: From Cell Culture to Human Studies

BACKGROUND

Chronic wounds are commonly associated with polymicrobial biofilm infections. In the last years, the extensive use of antibiotics has generated several antibiotic-resistant variants. To overcome this issue, alternative natural treatments have been proposed, including the use of microorganisms like probiotics. The aim of this manuscript was to review current literature concerning the application of probiotics for the treatment of infected chronic wounds.

METHODS

Relevant articles were searched in the Medline database using PubMed and Scholar, using the keywords "probiotics" and "wound" and "injuries", "probiotics" and "wound" and "ulcer", "biofilm" and "probiotics" and "wound", "biofilm" and "ulcer" and "probiotics", "biofilm" and "ulcer" and "probiotics", "probiotics" and "wound".

RESULTS

The research initially included 253 articles. After removal of duplicate studies, and selection according to specific inclusion and exclusion criteria, 19 research articles were included and reviewed, accounting for 12 in vitro, 8 in vivo studies and 2 human studies (three articles dealing with animal experiments included also in vitro testing). Most of the published studies about the effects of probiotics for the treatment of infected chronic wounds reported a partial inhibition of microbial growth, biofilm formation and quorum sensing.

DISCUSSION

The application of probiotics represents an intriguing option in the treatment of infected chronic wounds with multidrug-resistant bacteria; however, current results are difficult to compare due to the heterogeneity in methodology, laboratory techniques, and applied clinical protocols. Lactobacillus plantarum currently represents the most studied strain, showing a positive application in burns compared to guideline treatments, and an additional mean in chronic wound infections.

CONCLUSIONS

Although preliminary evidence supports the use of specific strains of probiotics in certain clinical settings such as infected chronic wounds, large, long-term clinical trials are still lacking, and further research is needed.

Skin Microbiome-The Next Frontier for Probiotic Intervention

The skin is the largest organ in the human body, and it orchestrates many functions that are fundamentally important for our survival. Although the skin might appear to present a relatively inhospitable or even hostile environment, a multitude of commensals and also some potentially pathogenic microorganisms have successfully adapted to survive and/or thrive within the diverse ecological niches created by the skin's topographical architecture. Dysbiosis within these microbial populations can result in the emergence and pathological progression of skin diseases. Unsurprisingly, this has led to a new focus of research both for the medical dermatology and cosmetic industries that is concerned with modulation of the skin microbiome to help address common microbially mediated or modulated conditions such as acne, body odour, and atopic dermatitis. This review presents an overview of our current understanding of the complex relationship of the skin with its microbiome and then introduces the concept of probiotic intervention for the management of microbial dysbiosis within the skin ecosystem.

Self-preserving gelatin emulgel containing whole cell probiotic for topical use: preclinical safety, efficacy, and germination studies

BACKGROUND

Dermal disorders, owing to disruption of skin-microflora balance can be served by direct application of probiotics. However, there are few topical whole probiotic products in market because of (i) loss of viability during manufacturing and storage(ii) inadequate germination and retention on skin. Presently we report a novel (IPA 201811010395) emulgel incorporatingBacillus coagulans (Unique IS-2) for possible topical use.

METHODS

Developed emulgel was characterized for particle size, texture, rheology, morphology, water activity, self-preservation, safety, and stability.

RESULTS

We successfully incorporated 97 ± 5% (1.7×10⁸CFU/g) Bacillus coagulans in honeycomb network of gelatin nanoparticles (≈600 nm). Maintenance of CFU at 30 ± 2°C, 65 ± 5% RH for 3 months confirmed viability of incorporated probiotic. Low water-activity (0.66-0.732a_w) and challenge test (0.05-0.5% viability) confirmed its self-preserving nature. Early initiation (6 h) and complete (24 h) spore germination was evident onrabbit skin. No cytotoxicity, dermal irritation or translocation established its safety. Faster wound closure and reduced oxidative stress (LPO, catalase, SOD, glutathione reductase) in comparison to Soframycin® (1%w/w Framycetin) was observed in excision wound in mice.

CONCLUSIONS

A whole cell probiotic formulation that is self-preserving, maintains probiotic viability, guarantees germination, and has wound healing properties was successfully formulated.

The differences in the number of fibroblasts and blood vessels after the topical and systemic administration of Lactobacillus casei Shirota probiotics for the treatment of traumatic ulcers in Wistar rats (Rattus norvegicus)

Background and Aim

The use of drugs as a therapy for traumatic ulcers may lead to drug resistance and other side effects. Lactobacillus casei Shirota can affect the number of fibroblasts and blood vessels in wound healing. The aim of this study was to investigate the difference in the number of fibroblast cells and blood vessels after the topical and systemic administration of L. casei Shirota probiotics in Wistar rats with traumatic ulcer.

Materials and Methods

Overall, 36 healthy male Wistar rats aged 2-3 months old and weighing 175-250 g in body weight were used as a sample. Traumatic ulcer was made on the labial fornix incisive inferior. The subject rats were divided into groups: (1) A control group over 3 days, (2) a group that used distilled water over 7 days, (3) a group that underwent topical treatment over 3 days, (4) a group that used probiotics administered topically over 7 days, (5) a group that underwent systemic treatment over 3 days, and (6) a group that took oral probiotics for the traumatic ulcers over 7 days. The number of fibroblasts and blood vessels was observed through a hematoxylin-eosin examination.

Results

Based on the results of the study, a significant difference was observed in the number of fibroblasts (p=0.00) and blood vessels (p=0.018) in the 3-day topical group that underwent a 3-day systemic administration of probiotics compared with the number of fibroblast cells in the 7-day topical group and 7-day systemic group (p=0.00).

Conclusion

Overall, significant differences were observed in the number of fibroblasts and blood vessels in Wistar rats with traumatic ulcer after undergoing the topical and systemic administration of L. casei Shirota probiotics.

The Ambivalent Role of Skin Microbiota and Adrenaline in Wound Healing and the Interplay between Them

After skin injury, wound healing sets into motion a dynamic process to repair and replace devitalized tissues. The healing process can be divided into four overlapping phases: hemostasis, inflammation, proliferation, and maturation. Skin microbiota has been reported to participate in orchestrating the wound healing both in negative and positive ways. Many studies reported that skin microbiota can impose negative and positive effects on the wound. Recent findings have shown that many bacterial species on human skin are able to convert aromatic amino acids into so-called trace amines (TAs) and convert corresponding precursors into dopamine and serotonin, which are all released into the environment. As a stress reaction, wounded epithelial cells release the hormone adrenaline (epinephrine), which activates the β2-adrenergic receptor (β2-AR), impairing the migration ability of keratinocytes and thus re-epithelization. This is where TAs come into play, as they act as antagonists of β2-AR and thus attenuate the effects of adrenaline. The result is that not only TAs but also TA-producing skin bacteria accelerate wound healing. Adrenergic receptors (ARs) play a key role in many physiological and disease-related processes and are expressed in numerous cell types. In this review, we describe the role of ARs in relation to wound healing in keratinocytes, immune cells, fibroblasts, and blood vessels and the possible role of the skin microbiota in wound healing.

Lactobacillus rhamnosus and Lactobacillus casei Affect Various Stages of Gardnerella Species Biofilm Formation

Bacterial vaginosis (BV) and its recurrence are most commonly associated with the formation of Gardnerella species biofilm. Probiotics are typically used to treat BV; however, the optimal period of Lactobacillus probiotic application in BV treatment remains uncertain. The present study aimed to explore the effects of Lactobacillus rhamnosus and Lactobacillus casei on various stages of biofilm formation in Gardnerella species. The biofilm-forming ability of seven strains, including one Gardnerella vaginalis ATCC 14018 and six clinically isolated Gardnerella species, was determined via gentian violet staining assay. Moreover, the sensitivity of the planktonic and biofilm forms toward metronidazole and clindamycin was assessed via microdilution broth method. L. rhamnosus Xbb-LR-1 and L. casei Xbb-LC-1 were added during various stages of biofilm formation in Gardnerella species and were cocultured for 24 h. The biofilm thickness of each sample was determined via confocal laser scanning microscopy (CLSM). The absolute quantities of Gardnerella species in each sample was obtained via real time polymerase chain reaction method, and the pH value was obtained using a pH indicator paper. Biofilm formation by Gardnerella species in a medium with distinct pH values was observed via gentian violet staining, CLSM, and scanning electron microscopy (SEM). The biofilm increased the resistance of Gardnerella species toward metronidazole and clindamycin. L. rhamnosus added at the initial biofilm formation stage in Gardnerella species exhibited highest inhibitory effect, with a percentage inhibition of 38.17% ± 1.35%. When the pH value of the culture medium was <4.5 or >6.5, ATCC 14018 could hardly form a biofilm; however, at pH ≥4.5 and ≤6.5, it was able to form a stronger biofilm. The amount of biofilm attained maximum value at optical density of 3.29 ± 0.28 (595 nm), pH 5.5, and at 36 h. Biofilm formation increases the resistance of Gardnerella species toward antibiotics. Maintaining an acidic vaginal environment with pH <4.5 and a vaginal microbiota dominated by Lactobacillus remarkably prevents the formation of Gardnerella species biofilm at the initial stage, which further has a significant impact on the treatment and prevention of biofilm-related infections.

Topical Probiotics in Dermatological Therapy and Skincare: A Concise Review

Recent studies have produced an increasing body of evidence that the intestinal microbiome plays an essential role in modulating systemic inflammation and skin diseases. The gut microbiome influences and modulates the host immune system, enabling immune tolerance of environmental and dietary antigens and protecting against pathogens. Emerging scientific evidence has demonstrated that oral probiotics can help treat certain skin diseases, such as acne, atopic dermatitis, photoaging, psoriasis, and wound healing. The aim of this paper is to review the current scientific evidence on topical probiotics and their effects on dermatological diseases and skincare and to clarify if the application of exogenous probiotics could also have the same benefit as oral probiotics in promoting positive bacterial balance to treat dermatologic conditions.

Staphylococcus epidermidis and Cutibacterium acnes: Two Major Sentinels of Skin Microbiota and the Influence of Cosmetics

Dermatological and cosmetics fields have recently started to focus on the human skin microbiome and microbiota, since the skin microbiota is involved in the health and dysbiosis of the skin ecosystem. Amongst the skin microorganisms, Staphylococcus epidermidis and Cutibacterium acnes, both commensal bacteria, appear as skin microbiota sentinels. These sentinels have a key role in the skin ecosystem since they protect and prevent microbiota disequilibrium by fighting pathogens and participate in skin homeostasis through the production of beneficial bacterial metabolites. These bacteria adapt to changing skin microenvironments and can shift to being opportunistic pathogens, forming biofilms, and thus are involved in common skin dysbiosis, such as acne or atopic dermatitis. The current evaluation methods for cosmetic active ingredient development are discussed targeting these two sentinels with their assets and limits. After identification of these objectives, research of the active cosmetic ingredients and products that maintain and promote these commensal metabolisms, or reduce their pathogenic forms, are now the new challenges of the skincare industry in correlation with the constant development of adapted evaluation methods.

Activation of aryl hydrocarbon receptor in Langerhans cells by a microbial metabolite of tryptophan negatively regulates skin inflammation

BACKGROUND

Skin commensal bacteria play important roles in skin homeostasis. Langerhans cells (LCs) are epidermis-resident dendritic cells that sense environmental stimuli and are critical in the induction of immune tolerance to allergen and bacterial skin flora. However, response of LCs to the metabolites of the skin microbiota is not clear.

OBJECTIVE

To explore the effects of the skin microbial metabolites on LCs activation.

METHODS

LCs derived from CD34+ hematopoietic stem cells in the cord blood were treated with a microbial metabolite of tryptophan, indole-3-aldehyde (IAId). Activation aryl hydrocarbon receptor (AhR) signaling, production of IL-10, and expression of receptor activator of NF-κB (RANK) / receptor activator of NF-κB ligand (RANKL) in LCs or keratinocytes were analyzed using quantitative PCR, western blotting and flow cytometry. LCs maturation induced by IAId and CD4⁺ T cell response induced by IAId-conditioned LCs were also investigated.

RESULTS

IAId induced the production of indoleamine 2,3-dioxygenase (IDO) and IL-10 in LCs through the activation of AhR. IAId promoted the expression of RANK and RANKL on LCs and keratinocytes in an AhR-dependent manner respectively, which might result in activation of NF-κB signaling and production of IL-10. Moreover, a mature phenotype of LCs was induced by IAId, and IAId-activated LCs inhibited CD4⁺ T cell proliferation and induced IL-10 secretion.

CONCLUSIONS

Our study revealed a negatively regulatory function of a tryptophan metabolite on LCs through the activation of AhR, and the microbial metabolites could be utilized in future treatment for inflammatory skin diseases.

Novel Rifampicin and Indocyanine Green Co-Loaded Perfluorocarbon Nanodroplets Provide Effective In Vivo Photo-Chemo-Probiotic Antimicrobility against Pathogen of Acne Vulgaris Cutibacterium acnes

Acne vulgaris is one of the most prevalent dermatological diseases among adolescents and is often associated with overgrowth of Cutibacterium acnes (C. acnes) in the pilosebaceous units. In this study, we aimed to develop novel rifampicin (RIF) and indocyanine green (ICG) co-loaded perfluorocarbon nanodroplets named RIPNDs which can simultaneously provide photo-, chemo-, and probiotic-antimicrobility, and explore their efficacy in treatment of C. acnes in vitro and in vivo. The RIPNDs were first characterized as being spherical in shape, with a size of 238.6 ± 7.51 nm and surface charge of -22.3 ± 3.5 mV. Then, the optimal dosages of Staphylococcus epidermidis-produced fermentation product medium (FPM) and RIPND were determined as 25% (v/v) and [RIF]/[ICG] = 3.8/20 μM, respectively, based on the analyses of inhibition zone and cytotoxicity in vitro. Through the in vivo study using C. acnes-inoculated mice, our data showed that the group treated with FPM followed by RIPNDs + near infrared (NIR) irradiation obtained the least granulocytes/macrophage-inflammatory protein 2 expression level in the epidermis, and showed a significantly lower microbial colony population compared to the groups treated with equal amount of RIF, FPM, RIPNDs, and/or combination of the above ± NIR. These results indicated that the RIPND-mediated photo-chemo-probiotic therapeutics was indeed able to rapidly suppress inflammatory response of the skin and provide a robust antibacterial effect against C. acnes with limited use of antibiotics. Taken altogether, we anticipate that the RIPND is highly potential for use in the clinical treatment of acne vulgaris.

Probiotics and prebiotics potential for the care of skin, female urogenital tract, and respiratory tract

The prebiotics and probiotics market is constantly growing due to the positive effects of its consumption on human health, which extends beyond the digestive system. In addition, the synbiotic products market is also expanding due to the synergistic effects between pre- and probiotics that provide additional benefits to consumers. Pre- and probiotics are being evaluated for their effectiveness to treat and prevent infectious diseases in other parts of the human body where microbial communities exist. This review examines the scientific data related to the effects of pre- and probiotics on the treatment of diseases occurring in the skin, female urogenital tract, and respiratory tract. The evidence suggests that probiotics consumption can decrease the presence of eczema in children when their mothers have consumed probiotics during pregnancy and lactation. In women, probiotics consumption can effectively prevent recurrent urinary tract infections. The consumption of synbiotic products can reduce respiratory tract infections and their duration and severity. However, the outcomes of the meta-analyses are still limited and not sufficiently conclusive to support the use of probiotics to treat infectious diseases. This is largely a result of the limited number of studies, lack of standardization of the studies, and inconsistencies between the reported results. Therefore, it is advisable that future studies consider these shortcomings and include the evaluation of the combined use of pre- and probiotics.

The Battle of Probiotics and Their Derivatives Against Biofilms

Biofilm-related infections have been a major clinical problem and include chronic infections, device-related infections and malfunction of medical devices. Since biofilms are not fully available for the human immune system and antibiotics, they are difficult to eradicate and control; therefore, imposing a global threat to human health. There have been avenues to tackle biofilms largely based on the disruption of their adhesion and maturation. Nowadays, the use of probiotics and their derivatives has gained a growing interest in battling against pathogenic biofilms. In the present review, we have a close look at probiotics with the ultimate objective of inhibiting biofilm formation and maturation. Overall, insights into the mechanisms by which probiotics and their derivatives can be used in the management of biofilm infections would be warranted.

Unique genetic basis of the distinct antibiotic potency of high acetic acid production in the probiotic yeast Saccharomyces cerevisiae var. boulardii

The yeast Saccharomyces boulardii has been used worldwide as a popular, commercial probiotic, but the basis of its probiotic action remains obscure. It is considered conspecific with budding yeast Saccharomyces cerevisiae, which is generally used in classical food applications. They have an almost identical genome sequence, making the genetic basis of probiotic potency in S. boulardii puzzling. We now show that S. boulardii produces at 37°C unusually high levels of acetic acid, which is strongly inhibitory to bacterial growth in agar-well diffusion assays and could be vital for its unique application as a probiotic among yeasts. Using pooled-segregant whole-genome sequence analysis with S. boulardii and S. cerevisiae parent strains, we succeeded in mapping the underlying QTLs and identified mutant alleles of SDH1 and WHI2 as the causative alleles. Both genes contain a SNP unique to S. boulardii (sdh1^F317Y and whi2^S287*) and are fully responsible for its high acetic acid production. S. boulardii strains show different levels of acetic acid production, depending on the copy number of the whi2^S287* allele. Our results offer the first molecular explanation as to why S. boulardii could exert probiotic action as opposed to S. cerevisiae. They reveal for the first time the molecular-genetic basis of a probiotic action-related trait in S. boulardii and show that antibacterial potency of a probiotic microorganism can be due to strain-specific mutations within the same species. We suggest that acquisition of antibacterial activity through medium acidification offered a selective advantage to S. boulardii in its ecological niche and for its application as a probiotic.

Revealing the secret life of skin - with the microbiome you never walk alone

The human skin microbiome has recently become a focus for both the dermatological and cosmetic fields. Understanding the skin microbiota, that is the collection of vital microorganisms living on our skin, and how to maintain its delicate balance is an essential step to gain insight into the mechanisms responsible for healthy skin and its appearance. Imbalances in the skin microbiota composition (dysbiosis) are associated with several skin conditions, either pathological such as eczema, acne, allergies or dandruff or non‐pathological such as sensitive skin, irritated skin or dry skin. Therefore, the development of approaches which preserve or restore the natural, individual balance of the microbiota represents a novel target not only for dermatologists but also for skincare applications. This review gives an overview on the current knowledge on the skin microbiome, the currently available sampling and analysis techniques as well as a description of current approaches undertaken in the skincare segment to help restoring and balancing the structure and functionality of the skin microbiota.

Efficacy of Using Probiotics with Antagonistic Activity against Pathogens of Wound Infections: An Integrative Review of Literature

The skin and its microbiota serve as physical barriers to prevent invasion of pathogens. Skin damage can be a consequence of illness, surgery, and burns. The most effective wound management strategy is to prevent infections, promote healing, and prevent excess scarring. It is well established that probiotics can aid in skin healing by stimulating the production of immune cells, and they also exhibit antagonistic effects against pathogens via competitive exclusion of pathogens. Our aim was to conduct a review of recent literature on the efficacy of using probiotics against pathogens that cause wound infections. In this integrative review, we searched through the literature published in the international following databases: PubMed, ScienceDirect, Web of Science, and Scopus using the search terms “probiotic” AND “wound infection.” During a comprehensive review and critique of the selected research, fourteen in vitro studies, 8 animal studies, and 19 clinical studies were found. Two of these in vitro studies also included animal studies, yielding a total of 39 articles for inclusion in the review. The most commonly used probiotics for all studies were well-known strains of the species Lactobacillus plantarum, Lactobacillus casei, Lactobacillus acidophilus, and Lactobacillus rhamnosus. All in vitro studies showed successful inhibition of chosen skin or wound pathogens by the selected probiotics. Within the animal studies on mice, rats, and rabbits, probiotics showed strong opportunities for counteracting wound infections. Most clinical studies showed slight or statistically significant lower incidence of surgical site infections, foot ulcer infection, or burn infections for patients using probiotics. Several of these studies also indicated a statistically significant wound healing effect for the probiotic groups. This review indicates that exogenous and oral application of probiotics has shown reduction in wound infections, especially when used as an adjuvant to antibiotic therapy, and therefore the potential use of probiotics in this field remains worthy of further studies, perhaps focused more on typical skin inhabitants as next-generation probiotics with high potential.

Antimicrobial activity of SYNBIO® probiotic formulation in pathogens isolated from chronic ulcerative lesions: in vitro studies

AIMS

Probiotics have the ability to enhance the immune system, produce anti-inflammatory action and promote wound healing process. The first aim of the study was to isolate pathogenic micro-organisms from sites of chronic ulcerative lesion. The second aim was to evaluate probiotic efficacy of SYNBIO^® (1:1 combination of Lactobacillus rhamnosus IMC 501^® and Lactobacillus paracasei IMC 502^® ) in counteracting wound infections.

METHODS AND RESULTS

Several bacterial pathogens were isolated from chronic ulcerative lesions and identified by morphological, biochemical and molecular techniques. SYNBIO^® probiotic formulation was investigated for its antimicrobial activity, minimum inhibitory concentration, co-aggregation and adherence capacity against the isolated pathogens. Moreover, SYNBIO was also tested in combination with some medical devices, using an in vitro model, in order to simulate a real ulcerative wound infection. Probiotic formulation demonstrated an inhibitory action against all the tested pathogens and their mixture (MIX), with an increased ability of co-aggregation during time. In addition, the adhesion percentage of probiotic micro-organisms to human keratinocyte (HaCaT cells) and human fibroblasts (NHF), calculated by an in vitro model, was 19% and 17% respectively, highlighting the possibility to create a protective environment preventing pathogens' biofilm formation in order to contrast infections.

CONCLUSIONS

SYNBIO^® probiotics showed a very good antimicrobial capacity and adhesion percentage to HaCaT cells and fibroblasts, giving the opportunity to be successfully used as complement to conventional therapies in the treatment of chronic ulcerative lesions.

SIGNIFICANCE AND IMPACT OF THE STUDY

A new therapeutic approach with probiotics (supplemented in topical applications, excluding side effects) able to eliminate pathogenic micro-organisms and improve healing of chronic ulcerative lesions.

Changing our microbiome: probiotics in dermatology

BACKGROUND

Commensal bacteria are a major factor in human health and disease pathogenesis. Interest has recently expanded beyond the gastrointestinal microbiome to include the skin microbiome and its impact on various skin diseases.

OBJECTIVES

Here we present current data reviewing the role of the microbiome in dermatology, considering both the gut and skin microflora. Our objective was to evaluate whether the clinical data support the utility of oral and topical probiotics for certain dermatological diseases.

METHODS

The PubMed and ClinicalTrials.gov databases were searched for basic science, translational research and clinical studies that investigated differences in the cutaneous microbiome and the impact of probiotics in patients with atopic dermatitis, acne vulgaris, psoriasis, chronic wounds, seborrhoeic dermatitis and cutaneous neoplasms.

RESULTS

Few clinical trials exist that explore the utility of probiotics for the prevention and treatment of dermatological diseases, with the exception of atopic dermatitis. Most studies investigated oral probiotic interventions, and of those utilizing topical probiotics, few included skin commensals. In general, the available clinical trials yielded positive results with improvement of the skin conditions after probiotic intervention.

CONCLUSIONS

Oral and topical probiotics appear to be effective for the treatment of certain inflammatory skin diseases and demonstrate a promising role in wound healing and skin cancer. However, more studies are needed to confirm these results. What's already known about this topic? The microbiome plays a role in human health and disease pathogenesis. Probiotics can manipulate the host microbiome and may confer health benefits for patients. Research to date has already begun to explore the utility of oral and topical probiotics for certain dermatological diseases. What does this study add? This review presents basic science and clinical trial data to support the role of the gut and skin microbiome in dermatology. Current data are reviewed on the use of probiotics in the prevention and treatment of skin diseases, including atopic dermatitis, acne vulgaris, psoriasis, seborrhoeic dermatitis, chronic wounds and cutaneous neoplasms. Future probiotic interventions are proposed.

Local Probiotic Lactobacillus crispatus and Lactobacillus delbrueckii Exhibit Strong Antifungal Effects Against Vulvovaginal Candidiasis in a Rat Model

A comprehensive knowledge of the vaginal ecosystem is critical for the development of successful approaches to the treatment of infections. The role of Lactobacilli in preventing vulvovaginal candidiasis (VVC) is controversial. In this study, we investigated the therapeutic effects and mechanism of Lactobacillus crispatus or delbrueckii on vaginitis caused by Candida albicans in a Sprague–Dawley rat model. A microbiological evaluation was performed by Gram staining and fungal colonies were enumerated. The antifungal efficacy of the two Lactobacillus strains was assessed by hematoxylin and eosin (HE) staining, transmission electron microscopy (TEM), immunohistochemical detection of interferon-γ (IFN-γ), interleukin (IL)-4, IL-17, and epithelial-derived IgG (RP125). Our in vitro results showed that the inhibitory activity against Candida colony-forming unit (CFU) counts was demonstrated by the two Lactobacillus strains (P < 0.001). Our results indicated that Lactobacillus administration played an indispensable role in maintaining the immune homeostasis, and decreasing the Th1/Th2 ratio (IFN-γ/IL-4) by regulating the epithelial secretion of cytokines that inhibit epithelial proinflammatory cytokine release, while increasing epithelial-derived IgG expression (P < 0.05), suggesting antibody-mediated protection. Our results implicate L. crispatus and L. delbrueckii as a potential adjunct biotherapeutic agent in women with VVC, especially for those with drug resistance, adverse effects or contraindications when using antifungal agents. Further large, long-term, well-planned clinical studies should be performed in clinical practice to determine their clinical potential of L. crispatus and L. delbrueckii as an adjunct treatment for VVC.