Antimicrobial activity of enterocins from Enterococcus faecalis SL-5 against Propionibacterium acnes, the causative agent in acne vulgaris, and its therapeutic effect

Probiotics in the Therapeutic Arsenal of Dermatologists

During the last years, numerous studies have described the presence of significant gut and skin dysbiosis in some dermatological diseases such as atopic dermatitis, psoriasis and acne, among others. How the skin and the gut microbiome play a role in those skin conditions is something to explore, which will shed light on understanding the origin and implication of the microbiota in their pathophysiology. Several studies provide evidence for the influence of probiotic treatments that target the modulation of the skin and intestinal microbiota in those disorders and a positive influence of orally administered probiotics on the course of these dermatosis. The pathologies in which the therapeutic role of the probiotic has been explored are mainly atopic dermatitis, psoriasis and acne. This article aims to review these three dermatological diseases, their relationship with the human microbiota and specially the effect of probiotics usage. In addition, the pathophysiology in each of them and the hypotheses about possible mechanisms of the action of probiotics will be described.

Effect of Antibacterial Root Canal Sealer on Persistent Apical Periodontitis

The infection of Enterococcus faecalis and its interacting microorganisms in the root canal could cause persistent apical periodontitis (AP). Antibacterial root canal sealer has favorable prospects to inhibit biofilms. The purpose of this study was to investigated the antibacterial effect of root canal sealer containing dimethylaminododecyl methacrylate (DMADDM) on persistent AP in beagle dogs for the first time. Persistent AP was established by a two-step infection with Enterococcus faecalis and multi-bacteria (Enterococcus faecalis, Lactobacillus acidophilus, Actinomycesnaeslundii, Streptococcus gordonii). Root canal sealer containing DMADDM (0%, 1.25%, 2.5%) was used to complete root canal filling. The volume of lesions and inflammatory grade in the apical area were evaluated by cone beam computer tomography (CBCT) and hematoxylin-eosin staining. Both Enterococcus-faecalis- and multi-bacteria-induced persistent AP caused severe apical destruction, and there were no significant differences in pathogenicity between them. DMADDM-modified sealer significantly reduced the volume of periapical lesion and inflammatory grade compared with the control group, among them, the therapeutic effect of the 2.5% group was better than the 1.25% group. In addition, E.faecalis-induced reinfection was more sensitive to the 2.5% group than multi-bacteria reinfection. This study shows that root canal sealer containing DMADDM had a remarkable therapeutic effect on persistent AP, especially on E. faecalis-induced reinfection.

Bacteriocins: Potential for Human Health

Due to the challenges of antibiotic resistance to global health, bacteriocins as antimicrobial compounds have received more and more attention. Bacteriocins are biosynthesized by various microbes and are predominantly used as food preservatives to control foodborne pathogens. Now, increasing researches have focused on bacteriocins as potential clinical antimicrobials or immune-modulating agents to fight against the global threat to human health. Given the broad- or narrow-spectrum antimicrobial activity, bacteriocins have been reported to inhibit a wide range of clinically pathogenic and multidrug-resistant bacteria, thus preventing the infections caused by these bacteria in the human body. Otherwise, some bacteriocins also show anticancer, anti-inflammatory, and immune-modulatory activities. Because of the safety and being not easy to cause drug resistance, some bacteriocins appear to have better efficacy and application prospects than existing therapeutic agents do. In this review, we highlight the potential therapeutic activities of bacteriocins and suggest opportunities for their application.

Bacteriocins as a new generation of antimicrobials: toxicity aspects and regulations

In recent decades, bacteriocins have received substantial attention as antimicrobial compounds. Although bacteriocins have been predominantly exploited as food preservatives, they are now receiving increased attention as potential clinical antimicrobials and as possible immune-modulating agents. Infections caused by antibiotic-resistant bacteria have been declared as a global threat to public health. Bacteriocins represent a potential solution to this worldwide threat due to their broad- or narrow-spectrum activity against antibiotic-resistant bacteria. Notably, despite their role in food safety as natural alternatives to chemical preservatives, nisin remains the only bacteriocin legally approved by regulatory agencies as a food preservative. Moreover, insufficient data on the safety and toxicity of bacteriocins represent a barrier against the more widespread use of bacteriocins by the food and medical industry. Here, we focus on the most recent trends relating to the application of bacteriocins, their toxicity and impacts.

The International Scientific Association of Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of postbiotics

In 2019, the International Scientific Association for Probiotics and Prebiotics (ISAPP) convened a panel of experts specializing in nutrition, microbial physiology, gastroenterology, paediatrics, food science and microbiology to review the definition and scope of postbiotics. The term 'postbiotics' is increasingly found in the scientific literature and on commercial products, yet is inconsistently used and lacks a clear definition. The purpose of this panel was to consider the scientific, commercial and regulatory parameters encompassing this emerging term, propose a useful definition and thereby establish a foundation for future developments. The panel defined a postbiotic as a "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host". Effective postbiotics must contain inactivated microbial cells or cell components, with or without metabolites, that contribute to observed health benefits. The panel also discussed existing evidence of health-promoting effects of postbiotics, potential mechanisms of action, levels of evidence required to meet the stated definition, safety and implications for stakeholders. The panel determined that a definition of postbiotics is useful so that scientists, clinical triallists, industry, regulators and consumers have common ground for future activity in this area. A generally accepted definition will hopefully lead to regulatory clarity and promote innovation and the development of new postbiotic products.

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.

Current Applications of Bacteriocin

Bacteriocins are multifunctional, ribosomally produced, proteinaceous substances with pronounced antimicrobial activity at certain concentrations. They are produced by bacteria and certain members of archaea to inhibit the growth of similar or closely related bacterial strains. These molecules have antimicrobial activity against pathogenic and deteriorating bacteria, which justifies their biotechnological potential. They are classified into 3 major classes based on their structural and physicochemical properties: class I bacteriocin, class II bacteriocin, and class III bacteriocin. Bacteriocins inhibit the growth of target organisms by functioning primarily on the cell envelope and by affecting gene expression and protein production within cells. The use of bacteriocins has been reported for the following: food preservation, diverse therapeutic purposes such as treatment of peptic ulcer, spermicidal agent, and woman care, anticancerous agent, veterinary use, skincare, and oral care, and also for plant growth promotion in agriculture among others.

Skin Protective Activity of LactoSporin-the Extracellular Metabolite from Bacillus Coagulans MTCC 5856

Background: Probiotics and their products are increasingly used in skincare in recent years. Postbiotics are defined as any substance derived through the metabolic activity of a probiotic microorganism, which exerts a direct or indirect beneficial effect on the host. The extracellular metabolites of probiotic bacteria have antimicrobial activities, protect against acne, and improve skin condition. We studied skin protective activities of the extracellular metabolite (LactoSporin) of a spore-forming probiotic Bacillus coagulans MTCC 5856 in vitro. Methods: LactoSporin was evaluated for antioxidant activity by free radical scavenging activity and reactive oxygen quenching activity in human dermal fibroblast cells. Protection of fibroblasts from UV-induced apoptosis and cell death was studied by flow cytometry and neutral red uptake assays. Enzyme inhibition assays were carried out for collagenase, Elastase, and Hyaluronidase. Gene expression studies were carried out using polymerase chain reaction. Results: LactoSporin showed antioxidant activity and was found to protect skin cells from UV-induced apoptosis and cell death. LactoSporin inhibited collagenase, elastase, and hyaluronidase activity and upregulated the expression of hyaluronan synthase, transforming growth factor and epidermal growth factor, which are associated with extracellular matrix integrity. Conclusions: These results suggest LactoSporin is a skin protective postbiotic with wide application in cosmetic formulations.

Novel Topical Application of a Postbiotic, LactoSporin®, in Mild to Moderate Acne: A Randomized, Comparative Clinical Study to Evaluate its Efficacy, Tolerability and Safety

Acne vulgaris is a common skin disorder of pilosebaceous units. The therapy for mild-to-moderate acne includes topical antibiotics, benzoyl peroxide and retinoids. In this open-label, randomized monocentric study, we compared the efficacy of LactoSporin® 2% w/w cream with benzoyl peroxide in 64 male and female subjects with mild-to-moderate acne for three weeks. The efficacy parameters were evaluated based on the dermatologist visual assessment and instrumental measurements using Sebumeter® MPA580, Antera 3DTM and VISIA CR 2.2 and subject self-assessment questionnaires. Adverse events were recorded throughout the study period. In order to understand the mechanism of action and properties of LactoSporin, the pH stability, thermostability, antimicrobial activity and 5-alpha reductase activity were evaluated in vitro. A significant improvement was observed in the dermatological assessment of closed comedones (p < 0.0001), open comedones (p = 0.0069) and papules count (p < 0.0001) in comparison to the baseline in both LactoSporin and benzoyl peroxide groups. The antera analysis showed significant improvement in redness (p < 0.0001) and elevation (p < 0.0001) (small and medium) in both the treatment groups. The sebumeter analysis showed a significant decrease in sebaceous secretion (p < 0.0001) for LactoSporin, which resulted in reduced oiliness, pimples, acne spots and redness around the acne spot. The product was found to be safe without any irritancy. LactoSporin was stable at an acidic pH and temperature range of 70 to 90 °C, with antimicrobial activity against various pathogenic bacteria, including Cutibacterium acnes. It was also a potent inhibitor of 5-alpha reductase activity. Thus, it can be concluded that the efficacy of LactoSporin is equivalent to benzoyl peroxide in the treatment of mild-to-moderate acne lesions and better than benzoyl peroxide for reducing the sebaceous secretion and oily, greasy nature of the skin, implying its efficacy in other sebohorriec conditions.

Antimicrobial activity of bacteriocins produced by Enterococcus isolates recovered from Egyptian homemade dairy products against some foodborne pathogens

The increasing mandate for fresh-like food products and the possible hazards of chemically preserved foods necessitate the search for alternatives. Bacteriocins represent a promising food biopreservative. In the present study, one hundred enterococci isolates recovered from Egyptian raw cow milk and homemade dairy products were screened for bacteriocin production. The overall detection rate was 10%. Three isolates, namely, Enterococcus faecalis (OE-7 and OE-12) and Enterococcus hirae (OE-9), showed the highest antibacterial activity with narrow spectrum against multidrug-resistant (MDR) Gram-positive foodborne bacteria: Enterococcus faecalis and Staphylococcus aureus. The antimicrobial activity was completely abolished by trypsin and proteinase K but not affected by lipase and/or amylase indicating the protein nature of the antimicrobial activity. Optimum conditions for bacteriocin production were cultivation in MRS broth at 37 °C, pH 6-6.5 for 16-24 h. The tested bacteriocins exhibited bactericidal activity on S. aureus subsp. aureus ATCC 25923; such activity was further investigated by transmission electron microscopy that revealed leakage and lysis of treated cells. Characterization of tested bacteriocins revealed high activity in a wide range of pH and temperature, storage stability, and heat resistance. PCR analysis revealed that the tested isolates produced multiple enterocins showing homology with the enterocins L50A, AS-48, and 31. Finally, this study reported potent antibacterial activity of bacteriocins derived from dairy products Enterococci against MDR foodborne and spoilage pathogens. The potency, specificity, and stability of these bacteriocins presented promising perspectives for application as biopreservatives in the food industry. The biopreservation of foods by bacteriocins produced by lactic acid bacteria recovered directly from foods remains an innovative approach.

The potential of probiotics for treating acne vulgaris: A review of literature on acne and microbiota

Acne is known as a chronic inflammatory skin disease with sever adverse effects on quality of life in the patients. The increasing resistance to antibiotics has decreased their effectiveness in treating acne. As viable microbial dietary supplements, probiotics provide health benefits through fighting pathogens and maintaining the homeostasis of the gut and skin microbiome. The present article reviewed the potential of probiotics as beneficial microorganisms for treating acne vulgaris. This review of literature was conducted through a bibliographic search of popular databases, including Science Direct, PubMed, Scielo and Medline, using keywords such as probiotics, prebiotics, synbiotics, microbiome, and acne vulgaris to determine potential applications of these beneficial microbiomes in treating acne vulgaris. Acne lesions are associated with increases in proportion of Propionibacterium acnes as a skin commensal bacterium. The environmental studies showed inhibitory effects of probiotics on P. acnes, mediating by antibacterial proteins and bacteriocin-like inhibitory substances, and their immunomodulatory effects onkeratinocytes and epithelial cells. Probiotics were also found to inhibit cytokine IL-8 in epithelial cells and keratinocytes, suggesting immunomodulatory activities. Moreover, glycerol fermentation by Staphylococcus epidermidis was found to be a natural skin defense against acne and an overgrowth inhibitor of P. acnes. As an antimicrobial agent in lotions and cosmetic formulations, Lactococcus sp. can decrease the inflammatory mediators that are produced by P. acnes and cause vasodilation, edema, mast cell degranulation and TNF-alpha release. Oral administration of probiotics was found to constitute an adjuvant therapy to conventional modalities for treating mild-to-moderate 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.

Review: Probiotics in dermatology

Probiotics are live microbial organisms that are beneficial to the host health when they are administered in adequate amounts. Since its introduction, the concept of probiotics has stimulated much interest and scientific research. Modulation of intestinal microbiota with probiotics is used as a therapeutic modality in many disease conditions. The role of probiotics in dermatological diseases like atopic dermatitis, acne, vaginal infections etc. is not yet established inspite of several studies on the same. As probiotics provide a safe and well-tolerated therapeutic modality in this era of antibiotic resistance and adverse effects, it becomes essential for us to validate the efficacy of its therapeutic supplementation. Herein, an attempt is made to review the current evidence from literature.

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.

Potential Role of the Microbiome in Acne: A Comprehensive Review

Acne is a highly prevalent inflammatory skin condition involving sebaceous sties. Although it clearly develops from an interplay of multiple factors, the exact cause of acne remains elusive. It is increasingly believed that the interaction between skin microbes and host immunity plays an important role in this disease, with perturbed microbial composition and activity found in acne patients. Cutibacterium acnes (C. acnes; formerly called Propionibacterium acnes) is commonly found in sebum-rich areas and its over-proliferation has long been thought to contribute to the disease. However, information provided by advanced metagenomic sequencing has indicated that the cutaneous microbiota in acne patients and acne-free individuals differ at the virulent-specific lineage level. Acne also has close connections with the gastrointestinal tract, and many argue that the gut microbiota could be involved in the pathogenic process of acne. The emotions of stress (e.g., depression and anxiety), for instance, have been hypothesized to aggravate acne by altering the gut microbiota and increasing intestinal permeability, potentially contributing to skin inflammation. Over the years, an expanding body of research has highlighted the presence of a gut–brain–skin axis that connects gut microbes, oral probiotics, and diet, currently an area of intense scrutiny, to acne severity. This review concentrates on the skin and gut microbes in acne, the role that the gut–brain–skin axis plays in the immunobiology of acne, and newly emerging microbiome-based therapies that can be applied to treat acne.

Preclinical studies of toxicity and safety of the AS-48 bacteriocin

The in vitro antimicrobial potency of the bacteriocin AS-48 is well documented, but its clinical application requires investigation, as its toxicity could be different in in vitro (haemolytic and antibacterial activity in blood and cytotoxicity towards normal human cell lines) and in vivo (e.g. mice and zebrafish embryos) models. Overall, the results obtained are promising. They reveal the negligible propensity of AS-48 to cause cell death or impede cell growth at therapeutic concentrations (up to 27 μM) and support the suitability of this peptide as a potential therapeutic agent against several microbial infections, due to its selectivity and potency at low concentrations (in the range of 0.3-8.9 μM). In addition, AS-48 exhibits low haemolytic activity in whole blood and does not induce nitrite accumulation in non-stimulated RAW macrophages, indicating a lack of pro-inflammatory effects. The unexpected heightened sensitivity of zebrafish embryos to AS-48 could be due to the low differentiation state of these cells. The low cytotoxicity of AS-48, the absence of lymphocyte proliferation in vivo after skin sensitization in mice, and the lack of toxicity in a murine model support the consideration of the broad spectrum antimicrobial peptide AS-48 as a promising therapeutic agent for the control of a vast array of microbial infections, in particular, those involved in skin and soft tissue diseases.

Functional Role of Probiotics and Prebiotics on Skin Health and Disease

Scientific and commercial interest of probiotics, prebiotics and their effect on human health and disease has increased in the last decade. The aim of this review article is to evaluate the role of pro- and prebiotics on the normal function of healthy skin as well as their role in the prevention and therapy of skin disease. Lactobacilli and Bifidobacterium are the most commonly used probiotics and thought to mediate skin inflammation, treat atopic dermatitis (AD) and prevent allergic contact dermatitis (ACD). Probiotics are shown to decolonise skin pathogens (e.g., P. aeruginosa, S. aureus, A. Vulgaris, etc.) while kefir is also shown to support the immunity of the skin and treat skin pathogens through the production of antimicrobial substances and prebiotics. Finally, prebiotics (e.g., Fructo-oligosaccharides, galacto-oligosaccharides and konjac glucomannan hydrolysates) can contribute to the treatment of diseases including ACD, acne and photo aging primarily by enhancing the growth of probiotics.

Bacteriocins: perspective for the development of novel anticancer drugs

Antimicrobial peptides (AMPs) from prokaryotic source also known as bacteriocins are ribosomally synthesized by bacteria belonging to different eubacterial taxonomic branches. Most of these AMPs are low molecular weight cationic membrane active peptides that disrupt membrane by forming pores in target cell membranes resulting in cell death. While these peptides known to exhibit broad-spectrum antimicrobial activity, including antibacterial and antifungal, they displayed minimal cytotoxicity to the host cells. Their antimicrobial efficacy has been demonstrated in vivo using diverse animal infection models. Therefore, we have discussed some of the promising peptides for their ability towards potential therapeutic applications. Further, some of these bacteriocins have also been reported to exhibit significant biological activity against various types of cancer cells in different experimental studies. In fact, differential cytotoxicity towards cancer cells as compared to normal cells by certain bacteriocins directs for a much focused research to utilize these compounds as novel therapeutic agents. In this review, bacteriocins that demonstrated antitumor activity against diverse cancer cell lines have been discussed emphasizing their biochemical features, selectivity against extra targets and molecular mechanisms of action.

Human Microbiome: Composition and Role in Inflammatory Skin Diseases

This review focuses on recent evidences about human microbiome composition and functions, exploring the potential implication of its impairment in some diffuse and invalidating inflammatory skin diseases, such as atopic dermatitis, psoriasis, hidradenitis suppurativa and acne. We analysed current scientific literature, focusing on the current evidences about gut and skin microbiome composition and the complex dialogue between microbes and the host. Finally, we examined the consequences of this dialogue for health and skin diseases. This review highlights how human microbes interact with different anatomic niches modifying the state of immune activation, skin barrier status, microbe-host and microbe-microbe interactions. It also shows as most of the factors affecting gut and skin microorganisms' activity have demonstrated to be effective also in modulating chronic inflammatory skin diseases. More and more evidences demonstrate that human microbiome plays a key role in human health and diseases. It is to be expected that these new insights will translate into diagnostic, therapeutic and preventive measures in the context of personalized/precision medicine.

Control of Propionibacterium acnes by natural antimicrobial substances: Role of the bacteriocin AS-48 and lysozyme

We report the high susceptibility of several clinical isolates of Propionibacterium acnes from different sources (skin, bone, wound exudates, abscess or blood contamination) to the head-to-tail cyclized bacteriocin AS-48. This peptide is a feasible candidate for further pharmacological development against this bacterium, due to its physicochemical and biological characteristics, even when it is growing in a biofilm. Thus, the treatment of pre-formed biofilms with AS-48 resulted in a dose- and time-dependent disruption of the biofilm architecture beside the decrease of bacterial viability. Furthermore, we demonstrated the potential of lysozyme to bolster the inhibitory activity of AS-48 against P. acnes, rendering high reductions in the MIC values, even in matrix-growing cultures, according to the results obtained using a range of microscopy and bioassay techniques. The improvement of the activity of AS-48 through its co-formulation with lysozyme may be considered an alternative in the control of P. acnes, especially after proving the absence of cytotoxicity demonstrated by these natural compounds on relevant human skin cell lines. In summary, this study supports that compositions comprising the bacteriocin AS-48 plus lysozyme must be considered as promising candidates for topical applications with medical and pharmaceutical purposes against dermatological diseases such as acne vulgaris.

The Genus Enterococcus: Between Probiotic Potential and Safety Concerns-An Update

A considerable number of strains belonging to different species of Enterococcus are highly competitive due to their resistance to wide range of pH and temperature. Their competitiveness is also owed to their ability to produce bacteriocins recognized for their wide-range effectiveness on pathogenic and spoilage bacteria. Enterococcal bacteriocins have attracted great research interest as natural antimicrobial agents in the food industry, and as a potential drug candidate for replacing antibiotics in order to treat multiple drugs resistance pathogens. However, the prevalence of virulence factors and antibiotic-resistance genes and the ability to cause disease could compromise their application in food, human and animal health. From the current regulatory point of view, the genus Enterococcus is neither recommended for the QPS list nor have GRAS status. Although recent advances in molecular biology and the recommended methods for the safety evaluation of Enterococcus strains allowed the distinction between commensal and clinical clades, development of highly adapted methods and legislations are still required. In the present review, we evaluate some aspects of Enterococcus spp. related to their probiotic properties and safety concerns as well as the current and potential application in food systems and treatment of infections. The regulatory status of commensal Enterococcus candidates for food, feed, probiotic use, and recommended methods to assess and ensure their safety are also discussed.

An approach on the potential use of probiotics in the treatment of skin conditions: acne and atopic dermatitis

Acne and Atopic Dermatitis (AD) are chronic inflammatory skin conditions with severe impact on a patient's life. Current treatments are related to adverse effects and do not represent a definitive cure. The present paper reviews the alterations in skin microbiome, specifically in acne and AD, and aims in searching for potential treatments based on benefic microorganisms, called probiotics. The review was made through bibliographic search of the main databases (Science Direct, PubMed, Scielo, Medline) between September 2015 and June 2016. Acne lesions create an environment that facilitates the excess growth of Propionibacterium acnes (P. acnes). AD is related to an increase in the proportion of Staphylococcus aureus (S. aureus) during flare-ups. Some microorganisms have been shown to act not only in the prevention but also in the competition for pathogenic microorganisms and beneficially affect the inflammatory process present in these conditions. Despite the high variety of tested bacteria, Staphylococcus, Streptococcus, Lactococcus, Lactobacillus, and Enterococcus are the ones which showed the highest potential to control acne, and Vitreoscilla filiformis (V. filiformis), Staphylococcus epidermidis (S. epidermidis), and species of Lactobacillus and Bifidobacterium in the treatment of AD. Many of these studies were in vitro, and more detailed research should be performed in order to prove the real efficacy and safety of probiotics in these situations. An interesting alternative seems to be the use of Bacteriocin-like inhibitory substances produced by probiotics, responsible for their antimicrobial activity.

Enterococcus faecalis AHG0090 is a Genetically Tractable Bacterium and Produces a Secreted Peptidic Bioactive that Suppresses Nuclear Factor Kappa B Activation in Human Gut Epithelial Cells

Enterococcus faecalis is an early coloniser of the human infant gut and contributes to the development of intestinal immunity. To better understand the functional capacity of E. faecalis, we constructed a broad host range RP4 mobilizable vector, pEHR513112, that confers chloramphenicol resistance and used a metaparental mating approach to isolate E. faecalis AHG0090 from a fecal sample collected from a healthy human infant. We demonstrated that E. faecalis AHG0090 is genetically tractable and could be manipulated using traditional molecular microbiology approaches. E. faecalis AHG0090 was comparable to the gold-standard anti-inflammatory bacterium Faecalibacterium prausnitzii A2-165 in its ability to suppress cytokine-mediated nuclear factor kappa B (NF-κB) activation in human gut-derived LS174T goblet cell like and Caco-2 enterocyte-like cell lines. E. faecalis AHG0090 and F. prausnitzii A2-165 produced secreted low molecular weight NF-κB suppressive peptidic bioactives. Both bioactives were sensitive to heat and proteinase K treatments although the E. faecalis AHG0090 bioactive was more resilient to both forms of treatment. As expected, E. faecalis AHG0090 suppressed IL-1β-induced NF-κB-p65 subunit nuclear translocation and expression of the NF-κB regulated genes IL-6, IL-8 and CXCL-10. Finally, we determined that E. faecalis AHG0090 is distantly related to other commensal strains and likely encodes niche factors that support effective colonization of the infant gut.

Nutrition-adaptive control of multiple-bacteriocin production by Weissella hellenica QU 13

AIM

To analyse nutrition-adaptive multiple-bacteriocin production by Weissella hellenica QU 13.

METHODS AND RESULTS

Weissella hellenica QU 13 produces two leaderless bacteriocins, weissellicins Y and M. Their production was studied in MRS and APT media by quantification analyses with liquid chromatography mass spectrometry (LC/MS), while transcriptional analysis of biosynthetic genes was performed by real-time reverse transcription (RT)-PCR. Weissellicin Y production was higher in MRS culture than in APT culture, while weissellicin M production was higher in APT culture than in MRS culture. APT medium contains a higher amount of thiamine than MRS medium, to enhance the growth of heterofermentative lactic acid bacteria. Therefore, thiamine addition to MRS culture enhanced the growth of W. hellenica QU 13; consequently, weissellicin Y production was decreased, while weissellicin M production was not affected. Furthermore, real-time RT-PCR analyses indicated that the transcriptional trends of their respective structural genes, welY and welM, were different from each other, and that these two genes' transcriptions responded to nutrition conditions.

CONCLUSION

Weissella hellenica QU 13 was demonstrated to control weissellicins Y and M production based on nutrition conditions. In addition, differential expression behaviour of weissellicins Y and M indicates that each of them would have separate roles to adapt to different environmental situations.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report that describes nutrition-adaptive multiple-bacteriocin production, in which thiamine inhibits bacteriocin production while it enhances the growth of the producer strain.

Supplementation with Lactobacillus rhamnosus SP1 normalises skin expression of genes implicated in insulin signalling and improves adult acne

Systemic supplementation with probiotics is increasingly being explored as a potential treatment strategy for skin disorders. Because both the gut-skin axis and dysregulation of insulin signalling have been implicated in the pathogenesis of adult acne, we designed the current study to evaluate the effect of supplementation with the probiotic strain Lactobacillus rhamnosus SP1 (LSP1) on skin expression of genes involved in insulin signalling and acne improvement in adult subjects. A pilot, randomised, double-blinded, placebo-controlled study was conducted with 20 adult subjects (14 females and 6 males; mean age: 33.7±3.3 years) with acne. Over a 12-week period, the probiotic group (n=10) consumed a liquid supplement containing LSP1 at a dose of 3×109 cfu/day (75 mg/day), whereas the placebo group (n=10) received a liquid lacking probiotics. Paired skin biopsies - one obtained before treatment initiation and one obtained at the end of the 12-week treatment period - were analysed for insulin-like growth factor 1 (IGF1) and forkhead box protein O1 (FOXO1) gene expression. The clinical criterion for efficacy was the investigator's global improvement rating on a five-point scale. Compared with baseline, the probiotic group showed a 32% (P<0.001) reduction, as well as a 65% increase (P<0.001) in IGF1 and FOXO1 gene expression in the skin, respectively. No such differences were observed in the placebo group. Patients in the probiotic group had an adjusted odds ratio of 28.4 (95% confidence interval = 2.2-411.1, P<0.05) to be rated by physicians as improved/markedly improved (versus worsened or unchanged) compared with the placebo group. We conclude that supplementation with the probiotic strain LSP1 normalises skin expression of genes involved in insulin signalling and improves the appearance of adult acne.

Health effects of probiotics on the skin

Skin is the largest organ of the body and is constantly exposed to physical, chemical, bacterial, and fungal challenges. It is well known that probiotics are helpful for specific disorders and different clinical studies have indicated that probiotics have special effects in cutaneous apparatus directly or indirectly that can be considerable from versatile aspects. Probiotic bacteriotherapy can have great potential in preventing and treating the skin diseases including eczema, atopic dermatitis, acne, and allergic inflammation or in skin hypersensitivity, UV-induced skin damage, wound protection, and as a cosmetic product. The current paper comprehensively reviews the different health effects of probiotics on the skin.

Probiotic approach to prevent antibiotic resistance

Probiotics are live microorganisms, mainly belonging to the genera Lactobacillus and Bifidobacterium, although also strain of other species are commercialized, that have a beneficial effect on the host. From the perspective of antibiotic use, probiotics have been observed to reduce the risk of certain infectious disease such as certain types of diarrhea and respiratory tract infection. This may be accompanied with a reduced need of antibiotics for secondary infections. Antibiotics tend to be effective against most common diseases, but increasingly resistance is being observed among pathogens. Probiotics are specifically selected to not contribute to the spread of antibiotic resistance and not carry transferable antibiotic resistance. Concomitant use of probiotics with antibiotics has been observed to reduce the incidence, duration and/or severity of antibiotic-associated diarrhea. This contributes to better adherence to the antibiotic prescription and thereby reduces the evolution of resistance. To what extent probiotics directly reduce the spread of antibiotic resistance is still much under investigation; but maintaining a balanced microbiota during antibiotic use may certainly provide opportunities for reducing the spread of resistances. Key messages Probiotics may reduce the risk for certain infectious diseases and thereby reduce the need for antibiotics. Probiotics may reduce the risk for antibiotic-associated diarrhea Probiotics do not contribute to the spread of antibiotic resistance and may even reduce it.

The effect of probiotics on immune regulation, acne, and photoaging

Probiotics are live micro-organisms that provide a health benefit to the host. The role of probiotics in the management of disease, as well as immune modification, has recently experienced a renewed interest in society, as probiotics can be found in products ranging from yogurt to facial creams. In this article, we discuss the role of probiotics in the development of the immune system, the treatment of acne and rosacea, and protection against aging and photodamage.

Acne vulgaris, probiotics and the gut-brain-skin axis: from anecdote to translational medicine

Acne vulgaris has long been postulated to feature a gastrointestinal mechanism, dating back 80 years to dermatologists John H. Stokes and Donald M. Pillsbury. They hypothesised that emotional states (e.g. depression and anxiety) could alter normal intestinal microbiota, increase intestinal permeability, and contribute to systemic inflammation. They were also among the first to propose the use of probiotic Lactobacillus acidophilus cultures. In recent years, aspects of this gut-brain-skin theory have been further validated via modern scientific investigations. It is evident that gut microbes and oral probiotics could be linked to the skin, and particularly acne severity, by their ability to influence systemic inflammation, oxidative stress, glycaemic control, tissue lipid content, and even mood. This intricate relationship between gut microbiota and the skin may also be influenced by diet, a current area of intense scrutiny by those who study acne. Here we provide a historical background to the gut-brain-skin theory in acne, followed by a summary of contemporary investigations and clinical implications.

Probiotics and prebiotics in dermatology

The rapid increase in the medical use of probiotics and prebiotics in recent years has confirmed their excellent safety profile. As immune modulators, they have been used in inflammatory skin conditions, such as atopic dermatitis. We review the literature regarding the use of probiotics and prebiotics in dermatology. Probiotics and prebiotics appear to be effective in reducing the incidence of atopic dermatitis in infants, but their role in atopic dermatitis treatment is controversial. Their role in acne, wound healing, and photoprotection is promising, but larger trials are needed before a final recommendation can be made.

What is the role of antimicrobial peptides (AMP) in acne vulgaris?

Acne vulgaris is the most common disorder of the pilosebaceous unit leading to inflamed skin characterized by the formation of comedones, papules, pustules and scarring. There is increasing evidence that the abundance of Propionibacterium acnes (P. acnes) in the inflamed acne lesions triggers inflammation. Therefore, in addition to treatment with retinoids, the use of antimicrobial agents has been established as a treatment option for acne. This indicates that antimicrobial mechanisms to control the growth of P. acnes may have an important influence on the severity of inflammatory acne. One import antimicrobial innate defense system comprises the production of antimicrobial peptides (AMP), small molecules with a broad spectrum of antimicrobial activity as well as immunomodulatory properties. Although the role of AMP in acne is still emerging, there is increasing evidence that AMP may be of importance in acne. The aim of this viewpoint is to provide some hypotheses about the potential function of AMP in the pathogenesis of acne and to discuss potential AMP-based therapies for the treatment of acne.

In Vitro Evaluation of Antimicrobial Activity of Lactic Acid Bacteria against Clostridium difficile

Clostridium difficile infection (CDI) has become a significant threat to public health. Although broad-spectrum antibiotic therapy is the primary treatment option for CDI, its use has evident limitations. Probiotics have been proved to be effective in the treatment of CDI and are a promising therapeutic option for CDI. In this study, 4 strains of lactic acid bacteria (LAB), namely, Lactobacillus rhamnosus (LR5), Lactococcuslactis (SL3), Bifidobacterium breve (BR3), and Bifidobacterium lactis (BL3) were evaluated for their anti-C. difficile activity. Co-culture incubation of C. difficile (10(6) and 10(10) CFU/ml) with each strain of LAB indicated that SL3 possessed the highest antimicrobial activity over a 24-hr period. The cell-free supernatants of the 4 LAB strains exhibited MIC50 values between 0.424 mg/ml (SL3) and 1.318 (BR3) mg/ml. These results may provide a basis for alternative therapies for the treatment of C. difficile-associated gut disorders.

Anti-infective properties of bacteriocins: an update

Bacteriocin production is a widespread phenomenon among bacteria. Bacteriocins hold great promise for the treatment of diseases caused by pathogenic bacteria and could be used in the future as alternatives to existing antibiotics. The anti-infective potential of bacteriocins for inhibiting pathogens has been shown in various food matrices including cheese, meat, and vegetables. However, their inhibition of pathogens in vivo remains unclear and needs more investigation, due mainly to difficulties associated with demonstrating their health benefits. Many bacteriocins produced by established or potential probiotic organisms have been evaluated as potential therapeutic agents and interesting findings have been documented in vitro as well as in a few in vivo studies. Some recent in vivo studies point to the efficacy of bacteriocin-based treatments of human and animal infections. While further investigation remains necessary before the possibilities for bacteriocins in clinical practice can be described more fully, this review provides an overview of their potential applications to human and veterinary health.

Dermatological problems of the puberty

Puberty is a period of life between childhood and adulthood. It is characterized by many changes in morphology and appearance of the body (biological maturation), in the psyche - development of personality (psychological maturation), and in the attitude towards one's own and the opposite sex (psychosexual maturation), and in the social role (social maturation). Dermatological problems of adolescence are mainly related to fluctuations in hormone levels, mainly androgens. They include acne, hair problems and excessive sweating. Acne vulgaris is the most frequently diagnosed dermatosis in patients aged between 11 and 30 years. It is believed that it affects about 80% of persons in this age group or even, taking into account lesions of low intensity, 100% of young people. Excessive sweating is a condition characterised by excessive production of sweat, resulting from high activity of sweat glands. The sweat glands are localised in almost all areas of the body surface but on the hands, feet, armpits and around the groin they are found at the highest density. Seborrhoeic dermatitis of the scalp is a chronic, relapsing, inflammatory dermatosis, which currently affects about 5% of the population. It affects mostly young people, particularly men.

Production of bioactive substances by intestinal bacteria as a basis for explaining probiotic mechanisms: bacteriocins and conjugated linoleic acid

The mechanisms by which intestinal bacteria achieve their associated health benefits can be complex and multifaceted. In this respect, the diverse microbial composition of the human gastrointestinal tract (GIT) provides an almost unlimited potential source of bioactive substances (pharmabiotics) which can directly or indirectly affect human health. Bacteriocins and fatty acids are just two examples of pharmabiotic substances which may contribute to probiotic functionality within the mammalian GIT. Bacteriocin production is believed to confer producing strains with a competitive advantage within complex microbial environments as a consequence of their associated antimicrobial activity. This has the potential to enable the establishment and prevalence of producing strains as well as directly inhibiting pathogens within the GIT. Consequently, these antimicrobial peptides and the associated intestinal producing strains may be exploited to beneficially influence microbial populations. Intestinal bacteria are also known to produce a diverse array of health-promoting fatty acids. Indeed, certain strains of intestinal bifidobacteria have been shown to produce conjugated linoleic acid (CLA), a fatty acid which has been associated with a variety of systemic health-promoting effects. Recently, the ability to modulate the fatty acid composition of the liver and adipose tissue of the host upon oral administration of CLA-producing bifidobacteria and lactobacilli was demonstrated in a murine model. Importantly, this implies a potential therapeutic role for probiotics in the treatment of certain metabolic and immunoinflammatory disorders. Such examples serve to highlight the potential contribution of pharmabiotic production to probiotic functionality in relation to human health maintenance.

Acne vulgaris, probiotics and the gut-brain-skin axis - back to the future?

Over 70 years have passed since dermatologists John H. Stokes and Donald M. Pillsbury first proposed a gastrointestinal mechanism for the overlap between depression, anxiety and skin conditions such as acne. Stokes and Pillsbury hypothesized that emotional states might alter the normal intestinal microflora, increase intestinal permeability and contribute to systemic inflammation. Among the remedies advocated by Stokes and Pillsbury were Lactobacillus acidophilus cultures. Many aspects of this gut-brain-skin unifying theory have recently been validated. The ability of the gut microbiota and oral probiotics to influence systemic inflammation, oxidative stress, glycemic control, tissue lipid content and even mood itself, may have important implications in acne. The intestinal microflora may also provide a twist to the developing diet and acne research. Here we provide a historical perspective to the contemporary investigations and clinical implications of the gut-brain-skin connection in acne.