The role of topical probiotics on wound healing: A review of animal and human studies

A potential therapeutic strategy of an innovative probiotic formulation toward topical treatment of diabetic ulcer: an in vivo study

BACKGROUND

The probiotic potential of Lacticacid bacteria has been studied in various medical complications, from gastrointestinal diseases to antibiotic resistance infections recently. Moreover, diabetic ulcer (DU) is known as one of the most significant global healthcare concerns, which comprehensively impacts the quality of life for these patients. Given that the conventional treatments of DUs have failed to prevent later complications completely, developing alternative therapies seems to be crucial.

METHODS

We designed the stable oleogel-based formulation of viable probiotic cells, including Lactobacillus rhamnosus (L. rhamnosus), Lactobacillus casei (L. casei), Lactobacillus fermentum (L. fermentum), and Lactobacillus acidophilus (L. acidophilus) individually to investigate their effect on wound healing process as an in vivo study. The wound repair process was closely monitored regarding morphology, biochemical, and histopathological changes over two weeks and compared it with the effects of topical tetracycline as an antibiotic approach. Furthermore, the antibiofilm activity of probiotic bacteria was assessed against some common pathogens.

RESULTS

The findings indicated that all tested lactobacillus groups (excluded L. casei) included in the oleogel-based formulation revealed a high potential for repairing damaged skin due to the considerably more levels of hydroxyproline content of tissue samples along with the higher numerical density of mature fibroblasts cell and volume density of hair follicles, collagen fibrils, and neovascularization in comparison with antibiotic and control groups. L. acidophilus and L. rhamnosus showed the best potential of wound healing among all lactobacillus species, groups treated by tetracycline and control groups. Besides, L. rhamnosus showed a significant biofilm inhibition activity against tested pathogens.

CONCLUSIONS

This experiment demonstrated that the designed formulations containing probiotics, particularly L. acidophilus and L. rhamnosus, play a central role in manipulating diabetic wound healing. It could be suggested as an encouraging nominee for diabetic wound-healing alternative approaches, though further studies in detailed clinical trials are needed.

Probiotics in Dermatology: An Evidence-based Approach

Probiotics are viable microorganisms that confer health benefits when administered to the host in adequate amounts. Over the past decade, there has been a growing demand for the use of oral and topical probiotics in several inflammatory conditions such as atopic dermatitis, psoriasis, acne vulgaris, etc., although their role in a few areas still remains controversial. The objective of this article is to shed light on understanding the origin and implications of microbiota in the pathophysiology of these dermatological conditions and the effect of probiotic usage. We have conducted a comprehensive search of the literature across multiple databases (PubMed, EMBASE, MEDLINE, and Google Scholar) on the role of probiotics in dermatological disorders. Commensal microbes of the skin and gastrointestinal tract play an important role in both health and disease. Increased use of probiotics has asserted a good safety profile, especially in this era of antibiotic resistance. With the advent of new products in the market, the indications, mechanism of action, efficacy, and safety profile of these agents need to be validated. Further studies are required. Oral and topical probiotics may be tried as a treatment or prevention modality in cutaneous inflammatory disorders, thus facilitating decreased requirement for topical or systemic steroids and antimicrobial agents. Tempering microbiota with probiotics is a safe and well-tolerated approach in this era of antimicrobial resistance.

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.

Probiotics in Wound Healing

Wound infections caused by opportunistic bacteria promote persistent infection and represent the main cause of delayed healing. Probiotics are acknowledged for their beneficial effects on the human body and could be utilized in the management of various diseases. They also possess the capacity to accelerate wound healing, due to their remarkable anti-pathogenic, antibiofilm, and immunomodulatory effects. Oral and topical probiotic formulations have shown promising openings in the field of dermatology, and there are various in vitro and in vivo models focusing on their healing mechanisms. Wound dressings embedded with prebiotics and probiotics are now prime candidates for designing wound healing therapeutic approaches to combat infections and to promote the healing process. The aim of this review is to conduct an extensive scientific literature review regarding the efficacy of oral and topical probiotics in wound management, as well as the potential of wound dressing embedding pre- and probiotics in stimulating the wound healing process.

Bedsore Healing Using Selenium-Enriched Lactobacillus brevis LSe: A Randomized, Double-Blind, Controlled Clinical Trial

Bedsores impose an important challenge to the healthcare system. Se-baring probiotics are considered effective agents in wound healing and inflammation reduction via several pathways. The present study focused on the administration of a Se-enriched probiotic, originally obtained from a traditional dairy product for bedsore healing. Daily doses of the probiotic were administered to 20 ICU patients for 14 days and the wound healing criteria were compared with those of the same group of ICU patients as control, both groups suffering from stages I and II bedsore (a randomized, double-blind, controlled clinical trial). The administered Se-enriched probiotic decreased the bedsore healing period significantly (on average by 2.4 days, P-value: 0.039), as well as bedsore size (on average by 7 mm2, nonsignificant) and bedsore grade (10%, nonsignificant) in the treatment group more efficiently than the control group. Some key laboratory parameters associated with inflammation were also improved in patients receiving the Se-supplemented probiotic. The limitations of this study include the low number of patients meeting inclusion criteria within the timeframe of the study, and the impossibility of following up patients after discharge from the ICU. In summary, this study revealed the effectiveness of the Se-enriched probiotic in bedsore improvement, suggesting consideration of the enriched probiotic as an auxiliary agent in bedsore management.

Promiscuous, persistent and problematic: insights into current enterococcal genomics to guide therapeutic strategy

Vancomycin-resistant enterococci (VRE) are major opportunistic pathogens and the causative agents of serious diseases, such as urinary tract infections and endocarditis. VRE strains mainly include species of Enterococcus faecium and E. faecalis which can colonise the gastrointestinal tract (GIT) of patients and, following growth and persistence in the gut, can transfer to blood resulting in systemic dissemination in the body. Advancements in genomics have revealed that hospital-associated VRE strains are characterised by increased numbers of mobile genetic elements, higher numbers of antibiotic resistance genes and often lack active CRISPR-Cas systems. Additionally, comparative genomics have increased our understanding of dissemination routes among patients and healthcare workers. Since the efficiency of currently available antibiotics is rapidly declining, new measures to control infection and dissemination of these persistent pathogens are urgently needed. These approaches include combinatory administration of antibiotics, strengthening colonisation resistance of the gut microbiota to reduce VRE proliferation through commensals or probiotic bacteria, or switching to non-antibiotic bacterial killers, such as bacteriophages or bacteriocins. In this review, we discuss the current knowledge of the genomics of VRE isolates and state-of-the-art therapeutic advances against VRE infections.

Skin Deep: The Potential of Microbiome Cosmetics

The interplay between the skin microbiome and its host is a complex facet of dermatological health and has become a critical focus in the development of microbiome cosmetics. The skin microbiome, comprising various microorganisms, is essential from birth, develops over the lifespan, and performs vital roles in protecting our body against pathogens, training the immune system, and facilitating the breakdown of organic matter. Dysbiosis, an imbalance of these microorganisms, has been implicated in a number of skin conditions such as acne, atopic dermatitis, and skin cancer. Recent scientific findings have spurred cosmetic companies to develop products that preserve and enhance the skin's microbial diversity balance. These products may incorporate elements like prebiotics, probiotics, and postbiotics, which are beneficial for the skin microbiome. Beyond topical products, there's increasing interest in ingestible beauty supplements (i.e. oral probiotics), highlighting the connection between the gut and skin. This review examines the influence of the microbiome on skin health and the emerging trends of microbiome skincare products.

Probiotic potential and wound-healing activity of Pediococcus pentosaceus strain AF2 isolated from Herniaria glabra L. which is traditionally used to make yogurt

Probiotics have been a part of our lives for centuries, primarily through fermented foods. They find applications in various fields such as food, healthcare, and agriculture. Nowadays, their utilization is expanding, highlighting the importance of discovering new bacterial strains with probiotic properties suitable for diverse applications. In this study, our aim was to isolate new probiotic bacteria. Herniaria glabra L., a plant traditionally used for yogurt making in some regions and recognized in official medicine in many countries, was chosen as the source for obtaining probiotic bacteria. We conducted bacterial isolation from the plant, molecularly identified the isolated bacteria using 16S rRNA sequencing, characterized their probiotic properties, and assessed their wound-healing effects. As a result of these studies, we identified the bacterium isolated from the plant as Pediococcus pentosaceus strain AF2. We found that the strain AF2 exhibited high resistance to conditions within the gastrointestinal tract. Our reliability analysis showed that the isolate had γ-hemolytic activity and displayed sensitivity to certain tested antibiotics. At the same time, AF2 did not show gelatinase and DNase activity. We observed that the strain AF2 produced metabolites with inhibitory activity against E. coli, B. subtilis, P. vulgaris, S. typhimurium, P. aeruginosa, K. pneumoniae, E. cloacae, and Y. pseudotuberculosis. The auto-aggregation value of the strain AF2 was calculated at 73.44%. Coaggregation values against E. coli and L. monocytogenes bacteria were determined to be 56.8% and 57.38%, respectively. Finally, we tested the wound-healing effect of the strain AF2 with cell culture studies and found that the strain AF2 promoted wound healing.

Effect of applying Lactiplantibacillus plantarum subsp. plantarum N793 to the scalps of men and women with thinning hair: a randomized, double-blind, placebo-controlled, parallel-group study

Lactiplantibacillus plantarum subsp. plantarum N793 (N793) is a lactic acid bacterium (LAB) isolated from corn. We previously showed that N793 increases the level of keratinocyte growth factor, which is required for hair growth, in the culture supernatant of human follicle dermal papilla cells. Additionally, an open-label, single-arm study reported that applying a lotion containing N793 to the scalp for 24 weeks improved hair density in men and women with thinning hair. The present study was a double-blind, placebo-controlled, parallel-group study aimed at verifying the efficacy of N793 for thinning hair. A lotion containing N793, and a control lotion (placebo) were applied once daily for 24 weeks to 104 healthy Japanese men and women. Analysis of all participants revealed no difference in hair density between the N793 and placebo groups. However, an additional analysis limited to participants with relatively mild progression of thinning hair showed a significantly better hair density in the N793 group than in the placebo group. These findings suggest that topical application of N793 improves thinning hair in men and women when the condition's progression is relatively mild.

Bacterial Biofilm in Chronic Wounds and Possible Therapeutic Approaches

Wound repair and skin regeneration is a very complex orchestrated process that is generally composed of four phases: hemostasis, inflammation, proliferation, and remodeling. Each phase involves the activation of different cells and the production of various cytokines, chemokines, and other inflammatory mediators affecting the immune response. The microbial skin composition plays an important role in wound healing. Indeed, skin commensals are essential in the maintenance of the epidermal barrier function, regulation of the host immune response, and protection from invading pathogenic microorganisms. Chronic wounds are common and are considered a major public health problem due to their difficult-to-treat features and their frequent association with challenging chronic infections. These infections can be very tough to manage due to the ability of some bacteria to produce multicellular structures encapsulated into a matrix called biofilms. The bacterial species contained in the biofilm are often different, as is their capability to influence the healing of chronic wounds. Biofilms are, in fact, often tolerant and resistant to antibiotics and antiseptics, leading to the failure of treatment. For these reasons, biofilms impede appropriate treatment and, consequently, prolong the wound healing period. Hence, there is an urgent necessity to deepen the knowledge of the pathophysiology of delayed wound healing and to develop more effective therapeutic approaches able to restore tissue damage. This work covers the wound-healing process and the pathogenesis of chronic wounds infected by biofilm-forming pathogens. An overview of the strategies to counteract biofilm formation or to destroy existing biofilms is also provided.

Emerging Multiscale Biofabrication Approaches for Bacteriotherapy

Bacteriotherapy is emerging as a strategic and effective approach to treat infections by providing putatively harmless bacteria (i.e., probiotics) as antagonists to pathogens. Proper delivery of probiotics or their metabolites (i.e., post-biotics) can facilitate their availing of biomaterial encapsulation via innovative manufacturing technologies. This review paper aims to provide the most recent biomaterial-assisted strategies proposed to treat infections or dysbiosis using bacteriotherapy. We revised the encapsulation processes across multiscale biomaterial approaches, which could be ideal for targeting different tissues and suit diverse therapeutic opportunities. Hydrogels, and specifically polysaccharides, are the focus of this review, as they have been reported to better sustain the vitality of the live cells incorporated. Specifically, the approaches used for fabricating hydrogel-based devices with increasing dimensionality (D)-namely, 0D (i.e., particles), 1D (i.e., fibers), 2D (i.e., fiber meshes), and 3D (i.e., scaffolds)-endowed with probiotics, were detailed by describing their advantages and challenges, along with a future overlook in the field. Electrospinning, electrospray, and 3D bioprinting were investigated as new biofabrication methods for probiotic encapsulation within multidimensional matrices. Finally, examples of biomaterial-based systems for cell and possibly post-biotic release were reported.

Antimicrobial Activity of Chitosan Scaffold Loaded with Soluble Factors of Different Probiotic Strains Against Multidrug Resistant Pseudomonas aeruginosa

Background

Bacterial infection remains the most frequent complication of burn injury, which can lead to sepsis, even if antibiotics are used topically and systemically. Pseudomonas aeruginosa (P. aeruginosa) is the main causative agent in many cases. The emergence of antibiotic-resistant strains in recent years has increased the need to find novel alternative therapies, such as probiotics. Therefore, this study aimed to examine the antimicrobial properties of probiotic cell-free supernatant (CFS), along with the potential use of a chitosan scaffold both as an antimicrobial agent and as a carrier for the delivery of these complexes.

Objective

Evaluation of the antimicrobial properties of cell-free soluble factors of probiotic bacteria both alone and in combination with chitosan scaffolds.

Materials and Methods

Nine isolates of P. aeruginosa previously identified by standard diagnostic tests were investigated. The antimicrobial effects of probiotics in the form of Pedilact® oral drop which contained three probiotic strains, Kidilact® sachet, which contained seven probiotic strains, and strains of Lactobacillus casei (L. casei) and Lactobacillus acidophilus (L. acidophilus) isolated from yogurt were studied by an agar well diffusion assay and by using CFS harvested at various growth stages, without pH neutralization. Chitosan with different concentrations of glutaraldehyde (GA) as a crosslinking agent was fabricated to produce a suitable scaffold for loading cell-free supernatants of probiotic strains. The scaffolds were then characterized using scanning electron microscopy. The antimicrobial properties of the CFS, chitosan, and chitosan scaffolds loaded with CFS were analyzed against MDR P. aeruginosa.

Results

In the agar well diffusion assay, CFS obtained from probiotic strains effectively inhibited the growth of a clinical strain of P. aeruginosa. This effect was observed when CFS was assessed without pH neutralization. Kidilact® was the most promising synbiotic formulation based on its inhibitory activity. The chitosan scaffold was successfully fabricated, as shown by SEM, and its structure was not affected by acidic CFS. The fabricated scaffolds were able to deliver CFS and, interestingly, antibacterial activity against P. aeruginosa when CFS was loaded on the chitosan scaffold was enhanced significantly.

Conclusion

The results of this study showed chitosan scaffold loaded with cell-free probiotics metabolites can be considered to be a promising antimicrobial dressing in wound healing applications.

Investigation of the potential roles of adipose stem cells and substances of natural origin in the healing process of E. coli infected wound model in Rats

Skin infections by pathogenic microorganisms are a serious problem due to the potential of dissemination through the bloodstream to various organs causing toxic effects that may be up to mortality. Escherichia coli (E. coli) is one of the most predominant Gram-negative bacterial species present globally with great attention for investigation. The current study is designed to investigate the possible role of adipose tissue-derived stem cells (ADSCs), as well as natural products such as Trichoderma viride (T. viride) extract, Saccharomyces boulardii (S. boulardii) solution in the enhancement of wound healing process in the infected skin with E. coli. Ninety-six female rats were divided into 8 groups (12 animal/group): normal skin, wounded skin, wounded skin infected with E. coli, infected-wounded skin treated by ADSCs, infected-wounded skin treated by T. viride extract, infected-wounded skin treated by S. boulardii solution, infected-wounded skin treated a combination of treatments, infected-wounded skin treated by gentamicin. At day 21 animal weights and bacterial count were detected and compared. Animals were sacrificed and skin from various groups was investigated using a light microscope for sections stained by (hematoxylin eosin, Masson trichrome, and PCNA) as well as transmission electron microscopy. Pro-inflammatory (IL-1β, TNF- α, and IL-13), anti-inflammatory cytokine (IL-4), and antioxidant enzymes (Superoxide dismutase, glutathione, and catalase) were assessed in various groups revealing that ADSCs lightly shift levels of these parameters in various rat groups to regular levels, while administration of T. viride extract, S. boulardii solution, their combination with ADSCs and gentamicin treatment drive the tested cytokines and enzymes to significant levels similar to a normal level where combination therapy gave the best result. The current findings revealed the possibility of using certain natural products as possible substitutes to regularly applied antibiotics with successive protective results in the wound infection model.

Microneedling with a Novel, n-3-PUFA-Rich Formulation Accelerates Inflammation Resolution to Improve Skin Recovery Outcomes in Adults with Healthy Skin

INTRODUCTION

Microneedling is a cosmetic procedure that leverages the skin's natural ability to heal in order to promote collagen formation and skin rejuvenation. To provide improved results, the technique can be combined with topical formulations. A new formulation of multiple actives, including omega-3 (n-3) polyunsaturated fatty acids (PUFAs), was designed to accelerate the resolution of inflammation and wound healing following micro-injury treatments, while enhancing the visible appearance of procedure results, including erythema, luminosity and skin texture.

METHODS

In this randomised, controlled, split-face study, we examined 32 healthy female participants aged 30-70 years for 4 weeks following microneedling treatment with a novel multiple-active-ingredient formulation or conventional microneedling protocol with a hyaluronic acid control serum. Changes in skin condition were assessed by blinded clinical photography and expert evaluation. Measurements were collected at baseline, 1 h, 1 day, 7 days and 28 days post treatment.

RESULTS

Significantly greater improvements in expert-assessed erythema, luminosity and skin texture were reported following application of the novel multiple-active-ingredient formulation than the hyaluronic acid control serum. This was confirmed by representative VISIA®-CR imaging.

CONCLUSION

These data provide new evidence for the role of a novel multiple-active-ingredient formulation for improving skin outcomes up to 28 days following microneedling in adults with healthy skin when compared with a hyaluronic acid serum. The n-3 PUFA content of this formulation may drive accelerated inflammation resolution and wound healing alongside the complementary action of the other active ingredients, leading to the observed improvements in erythema, luminosity and skin texture.

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Topical application of Lactobacilli successfully eradicates Pseudomonas aeruginosa biofilms and promotes wound healing in chronic wounds

Chronic wounds are difficult to treat due to the presence of biofilm which prevents wound healing. Pseudomonas aeruginosa is one of the most common pathogens found in chronic wounds and conventional treatment strategies have been ineffective in the eradication of its biofilm, without harming the surrounding healthy tissue at the same time. Here, we introduced an innovative approach applying the probiotic product Bio-K+ (containing three lactobacilli) topically as an antimicrobial and antibiofilm agent. We identified lactic acid as the main active component. While antibiotics and antiseptics such as silver-ions only demonstrated limited efficacy, Bio-K+ was able to completely eradicate mature P. aeruginosa biofilms established in an in-vitro and ex-vivo human skin model. Furthermore, it demonstrated biocompatibility in the co-culture with human dermal fibroblasts and accelerated the migration of fibroblasts in a cell migration assay promoting wound healing. To enhance clinical practicability, we introduced Bio-K+ into the hydrocolloid dressing Aquacel, achieving sustained release of lactic acid and biofilm eradication. This new treatment approach applying probiotics could represent a major improvement in the management of chronic wounds and can be extended in treating other biofilm-associated infections.

Topical Probiotic Formulation Promotes Rapid Healing in Dog Keratinocyte Cells: A Promising Approach for Wound Management

The use of probiotics has gained increasing attention as a strategy for wound healing to decrease microbial resistance to disinfectants and antibiotics. This study aimed to investigate the potential of a non-medicinal topical cocktail of probiotic bacteria (CPB) in promoting wound healing in dogs using in vitro scratch assay. Canine Progenitors Epidermal Keratinocytes (CPEK) were exposed to a prototype product formulated with CPB (PPP), non-formulated CPB, and the vehicle. The viability of CPB and CPEK cells was first evaluated in the co-culture model. Then, wound closure was analyzed over time. The CPB required a minimum concentration of 75 CFU/mL for better viability with CPEK. While the CPEK preserved 100% of their viability when PPP was diluted to up to 75,000 CFU/mL. At higher concentrations, the viability of CPEK was reduced by the concomitant effect of the non-formulated CPB and the vehicle. The formulated and non-formulated CPB and the vehicle seem to lead to a dose-dependent increase in cell migration compared to the control. Importantly, at the concentration of 750,000 CFU/mL, the PPP showed a 20% increase in wound closure. Taken together, our findings suggest the potential beneficial effects of the probiotic-based topical cocktail (PPP) on wound healing. However, to confirm and validate these effects, further experiments are necessary to provide more robust evidence and allow us to confidently establish the potential beneficial effects of the probiotic bacteria (CPB) in promoting wound healing.

The Potential Value of Probiotics after Dental Implant Placement

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

The Role of Probiotics in Skin Health and Related Gut-Skin Axis: A Review

Aging skin, wrinkles, pigmentation, and dryness are problems that plague people, and researchers are working to solve them. Recent studies have shown that intestinal microbiota homeostasis can influence skin health, demonstrating the existence of a gut-skin axis. Recently, improving skin health through probiotic interventions has been proposed, and micro-ecological skin care is becoming a popular concept. By regulating skin health and gut-skin axis interactions, probiotics can be used as potential management tools to suppress and improve skin diseases in multiple ways, including decreasing oxidative stress, suppressing inflammatory responses, and keeping immune effects. The purpose of this paper is to provide a comprehensive review of the application and mechanisms of probiotic-mediated gut microbiota homeostasis in skin care and to offer a theoretical basis for the application of probiotics in skin care.

Looking for the Ideal Probiotic Healing Regime

Wound healing is a multi-factorial response to tissue injury, aiming to restore tissue continuity. Numerous recent experimental and clinical studies clearly indicate that probiotics are applied topically to promote the wound-healing process. However, the precise mechanism by which they contribute to healing is not yet clear. Each strain appears to exert a distinctive, even multi-factorial action on different phases of the healing process. Given that a multi-probiotic formula exerts better results than a single strain, the pharmaceutical industry has embarked on a race for the production of a formulation containing a combination of probiotics capable of playing a role in all the phases of the healing process. Hence, the object of this review is to describe what is known to date of the distinctive mechanisms of each of the most studied probiotic strains in order to further facilitate research toward the development of combinations of strains and doses, covering the whole spectrum of healing. Eleven probiotic species have been analyzed, the only criterion of inclusion being a minimum of two published research articles.

A systematic review of natural products for skin applications: Targeting inflammation, wound healing, and photo-aging

BACKGROUND

Every day the skin is constantly exposed to several harmful factors that induce oxidative stress. When the cells are incapable to maintain the balance between antioxidant defenses and reactive oxygen species, the skin no longer can keep its integrity and homeostasis. Chronic inflammation, premature skin aging, tissue damage, and immunosuppression are possible consequences induced by sustained exposure to environmental and endogenous reactive oxygen species. Skin immune and non-immune cells together with the microbiome are essential to efficiently trigger skin immune responses to stress. For this reason, an ever-increasing demand for novel molecules capable of modulating immune functions in the skin has risen the level of their development, particularly in the field of natural product-derived molecules.

PURPOSE

In this review, we explore different classes of molecules that showed evidence in modulate skin immune responses, as well as their target receptors and signaling pathways. Moreover, we describe the role of polyphenols, polysaccharides, fatty acids, peptides, and probiotics as possible treatments for skin conditions, including wound healing, infection, inflammation, allergies, and premature skin aging.

METHODS

Literature was searched, analyzed, and collected using databases, including PubMed, Science Direct, and Google Scholar. The search terms used included "Skin", "wound healing", "natural products", "skin microbiome", "immunomodulation", "anti-inflammatory", "antioxidant", "infection", "UV radiation", "polyphenols", "polysaccharides", "fatty acids", "plant oils", "peptides", "antimicrobial peptides", "probiotics", "atopic dermatitis", "psoriasis", "auto-immunity", "dry skin", "aging", etc., and several combinations of these keywords.

RESULTS

Natural products offer different solutions as possible treatments for several skin conditions. Significant antioxidant and anti-inflammatory activities were reported, followed by the ability to modulate immune functions in the skin. Several membrane-bound immune receptors in the skin recognize diverse types of natural-derived molecules, promoting different immune responses that can improve skin conditions.

CONCLUSION

Despite the increasing progress in drug discovery, several limiting factors need future clarification. Understanding the safety, biological activities, and precise mechanisms of action is a priority as well as the characterization of the active compounds responsible for that. This review provides directions for future studies in the development of new molecules with important pharmaceutical and cosmeceutical value.

Sex differences in the skin microbiome of burn scars

Sex differences are observed in various spectrums of skin diseases, and there are differences in wound healing rate. Herein, sex differences were identified for the newly healed skin microbiome of burn patients. Fifty-two skin samples (26 normal skin, 26 burn scars) were collected from 26 burn patients (12 male, 14 female) and microbiota analysis was performed. The correlation between skin microbiota and biomechanical properties of burn scars was also investigated. There were no significant differences in clinical characteristics between male and female patients. Considering the biomechanical properties of burn scars and normal skin around it performed before sample collection, the mean erythema level of men's normal skin was significantly higher than that of women, whereas the mean levels of melanin, transepidermal water loss and skin hydration showed no significant sex differences. The erythrocyte sedimentation rate was significantly higher in females than that in males. Alpha diversity showed no significant differences between normal skin and burn scars in the male group. However, the scar was significantly higher than that of normal skin in the female group. Microbial network analysis revealed that the male group had more complex microbial network than the female group. Additionally, in the male group, the edge density and clustering coefficient were higher in burn scars when compared to normal skin, than the female group. There were sex differences in the results of microbiome of normal skin and burn scars. Some of the altered microbiota have been correlated with the biomechanical properties of burn scars. In conclusion, sex difference in the burn scar microbiome was confirmed. These results suggest that burn treatment strategies should vary with sex.

Photodynamic Therapy, Probiotics, Acetic Acid, and Essential Oil in the Treatment of Chronic Wounds Infected with Pseudomonas aeruginosa

As a prevalent medical problem that burdens millions of patients across the world, chronic wounds pose a challenge to the healthcare system. These wounds, often existing as a comorbidity, are vulnerable to infections. Consequently, infections hinder the healing process and complicate clinical management and treatment. While antibiotic drugs remain a popular treatment for infected chronic wounds, the recent rise of antibiotic-resistant strains has hastened the need for alternative treatments. Future impacts of chronic wounds are likely to increase with aging populations and growing obesity rates. With the need for more effective novel treatments, promising research into various wound therapies has seen an increased demand. This review summarizes photodynamic therapy, probiotics, acetic acid, and essential oil studies as developing antibiotic-free treatments for chronic wounds infected with Pseudomonas aeruginosa. Clinicians may find this review informative by gaining a better understanding of the state of current research into various antibiotic-free treatments. Furthermore. this review provides clinical significance, as clinicians may seek to implement photodynamic therapy, probiotics, acetic acid, or essential oils into their own practice.

The role of probiotics as wound healers: an overall view

A wound is an injury to the skin or damage to the body tissue. The healing process differs between various kinds of wounds. Treatment of hard-to-heal (chronic) wounds becomes challenging for healthcare practitioners, especially if patients have underlying health complications such as diabetes. Infection of wounds is another factor that interferes with the healing process and extends its duration. Active research is being conducted into the development of advanced wound dressing technologies. These wound dressings are intended to manage the exudate, reduce bacterial infection and speed up the healing process. Probiotics have been receiving much attention because of their potential application in the clinical field, especially in diagnostics and treatment strategies of various infectious and non-infectious diseases. The host immune-modulatory response and antimicrobial activity of probiotics are expanding their role in the development of improved wound dressing technology.

Lactobacillus delbrueckii subsp. bulgaricus derivatives for 3D printed alginate/hyaluronic acid self-crosslinking hydrogels: Manufacturing and wound healing potential

Derivatives [i.e. proteins and exopolysaccharides (EPS)] from Lactobacillus delbrueckii subsp. bulgaricus (LB) were extracted, characterized, and for the first time used in the production of novel self-crosslinking 3D printed alginate/hyaluronic acid (ALG/HA) hydrogels, as high-value functional biomaterials with therapeutic potentials in regenerative medicine applications. Derivatives coming from two different LB strains, LB1865 and LB1932, were tested in-vitro and compared for their cytotoxicity and effect on proliferation and migration on human fibroblast. EPS received particular attention as showing relevant dose-dependent cytocompatibility against the human fibroblast. The derivatives showed an ability to increase cell proliferation and migration, quantifiable between 10 and 20 % if compared to controls, with higher values for the derivatives obtained from the LB1932 strain. These were explained by liquid chromatography-mass spectrometry targeted protein biomarker analysis as a decrease in matrix-degrading and proapoptotic proteins, associated with an increase in collagen and antiapoptotic proteins production. LB1932 enriched hydrogel was found to be of benefit compared to control dressings, giving the more promising results as potential for in vivo skin wound healing tests.

Role of Lactiplantibacillus plantarum UBLP-40, Lactobacillus rhamnosus UBLR-58 and Bifidobacterium longum UBBL-64 in the Wound Healing Process of the Excisional Skin

The probiotics Lactiplantibacillus plantarum UBLP-40, Lactobacillus rhamnosus UBLR-58 and Bifidobacterium longum UBBL-64 seem to promote wound healing when applied topically. Our aim was to investigate their effect on the mRNA expression of pro-inflammatory, healing and angiogenetic factors during the healing process of a standardized excisional wound model in rats. Rats subjected to six dorsal skin wounds were allocated to Control; L. plantarum; combined formula of L. rhamnosus plus B. longum; L. rhamnosus; and B. longum treatments, applied every two days, along with tissue collection. The pro-inflammatory, wound-healing, and angiogenetic factors of mRNA expression were assessed by qRT-PCR. We found that L. plantarum exerts a strong anti-inflammatory effect in relation to L. rhamnosus-B. longum, given alone or in combination; the combined regime of L. rhamnosus-B. longum, works better, greatly promoting the expression of healing and angiogenic factors than L. plantarum. When separately tested, L. rhamnosus was found to work better than B. longum in promoting the expression of healing factors, while B. longum seems stronger than L. rhamnosus in the expression of angiogenic factors. We, therefore, suggest that an ideal probiotic treatment should definitively contain more than one probiotic strain to speed up all three healing phases.

Paraprobiotics strains accelerate wound repair by stimulating re-epithelialization of NIH-3T3 cells, decreasing inflammatory response and oxidative stress

The present study aimed to evaluate the potential and specificity of the inflammatory and antioxidant response of Microbe-Associated Molecular Patterns (MAMPs) in NIH-3T3 fibroblast cells, as well as in the healing process of skin wounds. Cells (NIH-3T3) were cultivated in supplemented specific medium. NIH-3T3 cells were treated with MAMPs (Bifidobacterium lactis or Lactobacillus casei or Lactobacillus gasseri or Lactobacillus paracasei or Streptococcus thermophilus), at two concentrations and insulted with LPS or H₂O₂. Cell viability, myeloperoxidase activity, nitrite/nitrate, oxidative damage and inflammatory parameters were measured. In addition, scratch assay was performed. Significant scratch closure was observed after 24 h and 48 h, and the effect of 0.1 g/mL MAMPs on wound healing was found to be highly statistically significant. In the viability cellular assay, Lactobacillus showed better response in 0.1 g/mL dose, whereas B. lactis and S. thermophilus showed better response in 0.01 g/mL dose. There was reduction in IL-6 and IL-1β levels in all treatments insulted with LPS. MAMP's showed preventive efficacy in reducing the effects caused by LPS. The MAMP's action in decreasing the production of ROS, inflammatory activity and increasing cell viability, besides significant cell proliferation during wound healing processes suggests remodeling mechanisms and new possibilities for wound healing.

Understanding the multifaceted etiopathogenesis of foot complications in individuals with diabetes

Diabetes mellitus, a chronic disease of metabolism, is characterized by a disordered production or cellular utilization of insulin. Diabetic foot disease, which comprises the spectrum of infection, ulceration, and gangrene, is one of the most severe complications of diabetes and is the most common cause of hospitalization in diabetic patients. The aim of this study is to provide an evidence-based overview of diabetic foot complications. Due to neuropathy, diabetic foot infections can occur in the form of ulcers and minor skin lesions. In patients with diabetic foot ulcers, ischemia and infection are the main causes of non-healing ulcers and amputations. Hyperglycemia compromises the immune system of individuals with diabetes, leading to persistent inflammation and delayed wound healing. In addition, the treatment of diabetic foot infections is challenging due to difficulty in accurate identification of pathogenic microorganisms and the widespread issue of antimicrobial resistance. As a further complicating factor, the warning signs and symptoms of diabetic foot problems can easily be overlooked. Issues associated with diabetic foot complications include peripheral arterial disease and osteomyelitis; accordingly, the risk of these complications in people with diabetes should be assessed annually. Although antimicrobial agents represent the mainstay of treatment for diabetic foot infections, if peripheral arterial disease is present, revascularization should be considered to prevent limb amputation. A multidisciplinary approach to the prevention, diagnosis, and treatment of diabetic patients, including those with foot ulcers, is of the utmost importance to reduce the cost of treatment and avoid major adverse consequences such as amputation.

Preparation and Evaluation of a Dosage Form for Individualized Administration of Lyophilized Probiotics

Probiotics have been used in human and veterinary medicine to increase resistance to pathogens and provide protection against external impacts for many years. Pathogens are often transmitted to humans through animal product consumption. Therefore, it is assumed that probiotics protecting animals may also protect the humans who consume them. Many tested strains of probiotic bacteria can be used for individualized therapy. The recently isolated Lactobacillus plantarum R2 Biocenol™ has proven to be preferential in aquaculture, and potential benefits in humans are expected. A simple oral dosage form should be developed to test this hypothesis by a suitable preparation method, i.e., lyophilization, allowing the bacteria to survive longer. Lyophilizates were formed from silicates (Neusilin® NS2N; US2), cellulose derivates (Avicel® PH-101), and saccharides (inulin; saccharose; modified starch® 1500). They were evaluated for their physicochemical properties (pH leachate, moisture content, water absorption, wetting time, DSC tests, densities, and flow properties); their bacterial viability was determined in conditions including relevant studies over 6 months at 4 °C and scanned under an electron microscope. Lyophilizate composed of Neusilin® NS2N and saccharose appeared to be the most advantageous in terms of viability without any significant decrease. Its physicochemical properties are also suitable for capsule encapsulation, subsequent clinical evaluation, and individualized therapy.

Wound healing and microbiome, an unexpected relationship

Skin wounds are common and represent a major public health and economical problem, with risks of complications and a significant negative impact on the quality of life of patients. Cutaneous wound healing is a tightly regulated process resulting in the restoration of tissue integrity. Wound healing involves the interaction of several skin, immune and vascular cells, growth factors and cytokines. However, external actors can play an important role in wound healing, such as the skin microbiome, which is the microbial commensal collection of bacteria, fungi and viruses inhabiting the skin. Indeed, recent advances have featured the interactions, within the wound environment, between different microbial species and between microbial species and the host immune system. This article reviews the relationship between the skin microbiome and the wound healing process. Although cutaneous wounds are a potential entry site for infection, the wound microbiome can have either a detrimental or a beneficial role on wound healing. Thus, targeting the skin microbiome could represent an essential part of wound healing management.

In Vitro Antibacterial and Wound Healing Activities Evoked by Silver Nanoparticles Synthesized through Probiotic Bacteria

The prospective application of probiotics is an adjuvant for the advancement of novel antimicrobial and wound-healing agents. Currently, probiotic bacteria are utilized for the biosynthesis of nanoparticles in the development of innovative therapeutics. The present study aimed at using nanoparticle-conjugated probiotic bacteria for enhanced antibacterial and wound-healing activity. In the present investigation, the probiotic bacteria were isolated from a dairy source (milk from domestic herbivores). They screened for antibacterial activity against infection-causing Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Bacillus subtilis and Staphylococcus aureus) pathogens. Further, the probiotic strain with higher bactericidal activity was used to synthesize silver, selenium, and copper nanoparticles. The isolated strain was found to be Lactiplantibacillus plantarum and it only has the ability to synthesize silver nanoparticles. This was verified using Ultra violet-Visible (UV-Vis) spectroscopy, where the test solution turned brown and the greatest UV-Vis absorptions peaked at 425 nm. Optimization studies on the synthesis of AgNPs (silver nanoparticles) are presented and the results show that stable synthesis was obtained by using a concentration of 1mM silver nitrate (AgNO₃) at a temperature of 37 °C with pH 8. The FTIR (Fourier transform infrared spectroscopy) study confirmed the involvement of functional groups from the cell biomass that were involved in the reduction process. Additionally, biosynthesized AgNPs showed increased antioxidant and antibacterial activities. The nano silver had a size distribution of 14 nm and was recorded with HR-TEM (high-resolution transmission electron microscopy) examination. The EDX (energy dispersive X-ray) analysis revealed 57% of silver groups found in the nanoparticle production. The biosynthesized AgNPs show significant wound-healing capabilities with 96% of wound closure (fibroblast cells) being observed through an in vitro scratch-wound assay. The cytotoxic experiments demonstrated that the biosynthesized AgNPs are not extremely hazardous to the fibroblast cells. The present study provides a new platform for the green synthesis of AgNPs using probiotic bacteria, showing significant antibacterial and wound-healing potentials against infectious pathogens.

Role of wound microbiome, strategies of microbiota delivery system and clinical management

Delayed wound healing is one of the most global public health threats affecting nearly 100 million people each year, particularly the chronic wounds. Many confounding factors such as aging, diabetic disease, medication, peripheral neuropathy, immunocompromises or arterial and venous insufficiency hyperglycaemia are considered to inhibit wound healing. Therapeutic approaches for slow wound healing include anti-infection, debridement and the use of various wound dressings. However, the current clinical outcomes are still unsatisfied. In this review, we discuss the role of skin and wound commensal microbiota in the different healing stages, including inflammation, cell proliferation, re-epithelialization and remodelling phase, followed by multiple immune cell responses to commensal microbiota. Current clinical management in treating surgical wounds and chronic wounds was also reviewed together with potential controlled delivery systems which may be utilized in the future for the topical administration of probiotics and microbiomes. This review aims to introduce advances, novel strategies, and pioneer ideas in regulating the wound microbiome and the design of controlled delivery systems.

Efficacy of probiotic Streptococcus thermophilus in counteracting TGF-β1-induced fibrotic response in normal human dermal fibroblasts

BACKGROUND

Abnormal and deregulated skin wound healing associated with prolonged inflammation may result in dermal fibrosis. Since the current therapeutic strategies revealed unsatisfactory, the investigation of alternative approaches such as those based on the use of specific probiotic strains could provide promising therapeutic options. In this study, we aimed to evaluate whether the lysate from S. thermophilus could antagonize the fibrogenic effects of TGF-β1 in normal human dermal fibroblasts (NHDF).

METHODS

NHDF were exposed to TGF-β1 to establish a fibrotic phenotype. Proliferation rate and cell number were measured using the IncuCyte® Live Cell Imager system and the trypan blue dye exclusion test. Phenoconversion markers (α-SMA and fibronectin) and collagen I levels were assessed by western blot and immunofluorescence. The mRNA levels of TGF-β1 were evaluated by RT-PCR. The Smad2/3 phosphorylation level as well as β-catenin and PPARγ expression, were assessed by western blot. The cell contractility function and migration of NHDF were studied using collagen gel retraction assay, and scratch wound healing assay, respectively. The effects of S. thermophilus lysate, alone or combined with TGF-β1, were evaluated on all of the above-listed parameters and markers associated with TGF-β1-induced fibrotic phenotype.

RESULTS

Exposure to the S. thermophilus lysate significantly reduced the key mediators and events involved in the abnormal activation of myofibroblasts by TGF-β1 within the fibrotic profile. The S. thermophilus treatment significantly reduced cell proliferation, migration, and myo-differentiation. In addition, the treatment with probiotic lysate reduced the α-SMA, fibronectin, collagen-I expression levels, and affected the collagen contraction ability of activated dermal fibroblasts. Moreover, the probiotic targeted the TGF-β1 signaling, reducing Smad2/3 activation, TGF-β1 mRNA level, and β-catenin expression through the upregulation of PPARγ.

CONCLUSION

This is the first report showing that S. thermophilus lysate had a remarkable anti-fibrotic effect in TGF-β1-activated NHDF by inhibiting Smad signaling. Notably, the probiotic was able to reduce β-catenin and increase PPARγ levels. The findings support our point that S. thermophilus may help prevent or treat hypertrophic scarring and keloids.

Evaluation of the Preliminary Safety, Tolerability and Colonisation Efficacy of Topical Probiotic Formulations Containing Micrococcus luteus Q24 in Healthy Human Adults

Probiotics developed for topical applications in humans have the potential to beneficially modulate microbial imbalances on the skin surface and thereby improve skin health. This study was conducted to determine whether topical formulations containing the human skin commensal Micrococcus luteus strain Q24 (BLIS Q24) are safe, tolerable and efficacious when used by healthy human subjects. M. luteus Q24 was assessed in vitro for haemolytic activity and its antibiotic susceptibility profile. Formulations of strain Q24 were evaluated for the preliminary safety and tolerability in healthy human participants. Forty-seven adults were randomly assigned to four single-site, single-blind randomised placebo or baseline controlled or active-controlled trials. Skin swab samples were collected for differential viable counts to monitor levels of probiotic colonisation. M. luteus Q24 was found to be non-haemolytic and susceptible to commonly used antibiotics. The M. luteus Q24 formulations were safe and tolerable and >90% of the participants reported improvements from baseline in the appearance (e.g., radiance and hydration) of their treated skin. Additionally, participants observed a reduction in pore size, skin clarity and enhanced skin softness. No adverse effects were reported. A dose-related significant increase was observed in the levels of M. luteus Q24 isolated from skin swabs of the probiotic-treated subjects. Placebo-controlled trials in human subjects involving the topical application of different doses of M. luteus Q24 formulations were supportive of the safety, tolerability and efficacy of probiotic M. luteus Q24. Self-reported skin health assessments by the subjects indicated that M. luteus Q24 has good potential as a probiotic for improving skin health quality.

The little-known history of cleanliness and the forgotten pioneers of handwashing

Handwashing is a simple method for preventing the spread of pathogens. It is now common practice, but this was not always the case. Advocating for it often costed a doctor his career in the 1840s. Hospitals in the early 1800s had little idea of the significance of hygiene; thus, they were often mocked as disease-producing incubators or as "houses of death." Many of the ill and dying were kept on wards with no ventilation or access to clean water; hospitals were found to offer only the most basic care. The mortality rate for patients admitted to hospital was three to five times greater than that for individuals cared for at home. Doctors did not routinely wash their hands until the mid-1800s, and they would proceed straight from dissecting a corpse to delivering a baby, providing the basis for the spread of puerperal fever. Despite advances in modern medicine, healthcare providers still face the issue of infection outbreaks caused by patient care. While the body of scientific data supporting hand hygiene as the key strategy to prevent the spread of pathogens is substantial, we highlight that achieving this crucial, long-awaited breakthrough was a hard task through history.

Polymicrobial Foot Infection Patterns Are Common and Associated With Treatment Failure

BACKGROUND

That foot infections are predominately polymicrobial has long been recognized, but it is not clear if the various species co-occur randomly or in patterns. We sought nonrandom species co-occurrence patterns that might help better predict prognosis or guide antimicrobial selection.

METHODS

We analyzed tissue (bone, skin, and other soft tissue), fluid, and swab specimens collected from initial foot infection episodes during a 10-year period using a hospital registry. Nonrandom co-occurrence of microbial species was identified using simple pairwise co-occurrence rates adjusted for multiple comparisons, Markov and conditional random fields, and factor analysis. A historical cohort was used to validate pattern occurrence and identify clinical significance.

RESULTS

In total, 156 unique species were identified among the 727 specimens obtained from initial foot infection episodes in 694 patients. Multiple analyses suggested that Staphylococcus aureus is negatively associated with other staphylococci. Another pattern noted was the co-occurrence of alpha-hemolytic Streptococcus, Enterococcus fecalis, Klebsiella, Proteus, Enterobacter, or Escherichia coli, and absence of both Bacteroides and Corynebacterium. Patients in a historical cohort with this latter pattern had significantly higher risk-adjusted rates of treatment failure.

CONCLUSIONS

Several nonrandom microbial co-occurrence patterns are frequently seen in foot infection specimens. One particular pattern with many Proteobacteria species may denote a higher risk for treatment failure. Staphylococcus aureus rarely co-occurs with other staphylococci.

Topical administration of pterostilbene accelerates burn wound healing in diabetes through activation of the HIF1α signaling pathway

Impaired wound healing is one of a variety of severe diabetic complications and involves many factors, including consistent oxidative stress, prolonged inflammation, impaired angiogenesis, and delayed re-epithelialization. Despite the severe negative impacts that impaired wound healing has on patients' lives, detailed mechanisms and effective therapies are still not fully developed. In this study, we aim to investigate the potential effects and mechanisms of topical administration of pterostilbene and resveratrol on burn wound healing in diabetes. Our in vitro experiments in human umbilical vein endothelial cells showed that long term exposure of hyperglycemia induces oxidative stress and suppression of hypoxia inducible factor1α (HIF1α) signaling pathway, and pterostilbene treatment completely, while resveratrol treatment partly, reversed this effect. Further in vivo experiments in diabetic rats showed that topical administration of pterostilbene exhibited stronger efficacy than resveratrol in normalizing oxidative stress, HIF1α activity, and accelerating burn wound healing in diabetes. We conclude that topical administration of pterostilbene accelerates burn wound healing in diabetes through activation of the HIF1α signaling pathway; thus, pterostilbene may be a potential candidate for clinical treatment of burn wound healing in diabetes.

The 3-D configuration of excisional skin wound healing after topical probiotic application

Nowadays, there is an increasing knowledge that probiotic bacteria, topically applied, affects skin pathology. The objective of this study is to evaluate the effect on wound healing of locally applied probiotics by calculating the 3-D configuration of a standardized excisional wound. Fifty-two male Wistar rats were randomly allocated into groups: control, PRO1 [L. plantarum] and PRO2 [L. rhamnosus, B. longum]. Six excisional full-thickness wounds were created on each dorsum by an 8-mm circular biopsy punch; probiotics or saline were applied on days 0, 2, 4, 8, 16, photos of the wounds taken and specimens excised for histology [4 rats/group/time-point]. Both probiotic-groups exhibited accelerated healing significantly faster than the control, throughout, PRO2 exhibiting finally the best results [day 16]. However, only on day 2, did PRO1 exhibit the best results [wounded area, borders distance and epitheliazation line]. The results clearly demonstrate that the topical application of probiotics significantly improves the healing process, each strain working differently and more effectively in different healing phases. Thus, a combined formula containing different probiotics to modulate various healing phases is desirable. To this end our research continous.

Immunomodulatory Efficacy-Mediated Anti-HCV and Anti-HBV Potential of Kefir Grains; Unveiling the In Vitro Antibacterial, Antifungal, and Wound Healing Activities

The utilization of fermented foods with health-promoting properties is becoming more popular around the world. Consequently, kefir, a fermented milk beverage made from kefir grains, was shown in numerous studies to be a probiotic product providing significant health benefits. Herein, we assessed the antibacterial and antifungal potential of kefir against a variety of pathogenic bacteria and fungi. This study also showed the effectiveness of kefir in healing wounds in human gastric epithelial cells (GES-1) by (80.78%) compared with control (55.75%) within 48 h. The quantitative polymerase chain reaction (qPCR) results of kefir-treated HCV- or HBV- infected cells found that 200 µg/mL of kefir can eliminate 92.36% of HCV and 75.71% of HBV relative to the untreated infected cells, whereas 800 µg/mL (the highest concentration) completely eradicated HCV and HBV. Moreover, the estimated IC₅₀ values of kefir, at which HCV and HBV were eradicated by 50%, were 63.84 ± 5.81 µg/mL and 224.02 ± 14.36 µg/mL, correspondingly. Kefir can significantly suppress the elevation of TNF-α and upregulate IL-10 and INF-γ in both treated HCV- and HBV-infected cells. High-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) analysis of kefir revealed the presence of numerous active metabolites which mainly contribute to the antimicrobial, antiviral, and immunomodulatory activities. This study demonstrated, for the first time, the anti-HBV efficacy of kefir while also illustrating the immunomodulatory impact in the treated HBV-infected cells. Accordingly, kefir represents a potent antiviral agent against both viral hepatitis C and B, as well as having antimicrobial and wound healing potential.

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.

A Novel Effective Formulation of Bioactive Compounds for Wound Healing: Preparation, In Vivo Characterization, and Comparison of Various Postbiotics Cold Creams in a Rat Model

The wound is a break in the integrity of the skin produced by injury, illness, or operation. Wound healing is an essential dynamic biological/physiological process that occurs in response to tissue damage. The huge health, economic, and social effects of wounds on patients and societies necessitate the research to find novel potential therapeutic agents in order to promote wound healing. Postbiotics, the newest member of the biotics family, are valuable functional bioactive substances produced by probiotics through their metabolic activity, which have several beneficial properties, including immunomodulatory, anti-inflammatory, antimicrobial, and angiogenesis characteristics, resulting in acceleration of wound healing. In the current study, three topical cold cream formulations containing postbiotics obtained from Lactobacillus fermentum, Lactobacillus reuteri, or Bacillus subtilis sp. natto probiotic strains were prepared. The effectiveness and wound healing activity of the developed postbiotics cold cream formulations were investigated compared to cold cream without postbiotics and no treatment via wound closure investigation, hydroxyproline content assay, and histological assessment in 25 Sprague Dawley rats divided into five groups. Interestingly, analysis of the results revealed that all three formulations containing postbiotics significantly accelerated the wound healing process. However, in general, the Bacillus subtilis natto cold cream manifested a better wound healing property. The pleasing wound healing characteristics of the topical postbiotics cold creams through the in vivo experiment suggest that formulations containing postbiotics can be considered as a promising nominee for wound healing approaches.

Heat-Killed Lactobacilli Preparations Promote Healing in the Experimental Cutaneous Wounds

Probiotics are defined as microorganisms with beneficial health effects when consumed by humans, being applied mainly to improve allergic or intestinal diseases. Due to the increasing resistance of pathogens to antibiotics, the abuse of antibiotics becomes inefficient in the skin and in systemic infections, and probiotics may also provide the protective effect for repairing the healing of infected cutaneous wounds. Here we selected two Lactobacillus strains, L. plantarum GMNL-6 and L. paracasei GMNL-653, in heat-killed format to examine the beneficial effect in skin wound repair through the selection by promoting collagen synthesis in Hs68 fibroblast cells. The coverage of gels containing heat-killed GMNL-6 or GMNL-653 on the mouse tail with experimental wounds displayed healing promoting effects with promoting of metalloproteinase-1 expression at the early phase and reduced excessive fibrosis accumulation and deposition in the later tail-skin recovery stage. More importantly, lipoteichoic acid, the major component of Lactobacillus cell wall, from GMNL-6/GMNL-653 could achieve the anti-fibrogenic benefit similar to the heat-killed bacteria cells in the TGF-β stimulated Hs68 fibroblast cell model. Our study offers a new therapeutic potential of the heat-killed format of Lactobacillus as an alternative approach to treating skin healing disorders.

Avoidance of milk and dairy products after oral surgery-is such a recommendation still valid? A cross-sectional study among German and international oral and maxillofacial surgeons and dental practitioners with review of the literature

PURPOSE

For prevention of wound-healing complications, patients in German-speaking countries are traditionally advised to avoid consumption of milk and dairy products after oral surgery. In the absence of national and international guidelines, this study investigates scientific evidence and compares international practice, frequency scale, and rationale behind such recommendation.

METHODS

Comparison of a German cross-sectional mono-center-questionnaire pilot study and a survey among international oral and maxillofacial surgeons (OMFS), specialized oral surgeons and general dentists, evaluating international practice regarding post-operative dietary and nutrition recommendations. Our literature review further assessed scientific evidence for relevant effects of probiotics, prebiotics, and/or synbiotics.

RESULTS

Among German study participants, 56% (n = 64/114) advise patients to avoid milk and dairy products, with 42% of OMFS (n = 38) and 65% (n = 76) of the general dentists recommending abstention (p = .027). In striking contrast, such recommendation could not be identified in our international survey (n = 143) (t test, p < .001) nor in the literature. There were significant differences between German and international study participants regarding the rationale for dietary recommendations, with dental schools and literature most frequently indicated as sources (Fisher's exact test, p < .001).

CONCLUSION

The hypothesis of a harmful effect of the consumption of milk and dairy products after dentoalveolar surgery could not be supported by evidence. The recommendation to avoid dairy products post-surgery was identified as a specific phenomenon practiced almost exclusively in German-speaking countries. Corresponding recommendations, most probably based on a now irrelevant risk of contracting tuberculosis from milk products, can at present no longer be substantiated.

The Insights of Microbes' Roles in Wound Healing: A Comprehensive Review

A diverse range of normal flora populates the human skin and numbers are relatively different between individuals and parts of the skin. Humans and normal flora have formed a symbiotic relationship over a period of time. With numerous disease processes, the interaction between the host and normal flora can be interrupted. Unlike normal wound healing, which is complex and crucial to sustaining the skin’s physical barrier, chronic wounds, especially in diabetes, are wounds that fail to heal in a timely manner. The conditions become favorable for microbes to colonize and establish infections within the skin. These include secretions of various kinds of molecules, substances or even trigger the immune system to attack other cells required for wound healing. Additionally, the healing process can be slowed down by prolonging the inflammatory phase and delaying the wound repair process, which causes further destruction to the tissue. Antibiotics and wound dressings become the targeted therapy to treat chronic wounds. Though healing rates are improved, prolonged usage of these treatments could become ineffective or microbes may become resistant to the treatments. Considering all these factors, more studies are needed to comprehensively elucidate the role of human skin normal flora at the cellular and molecular level in a chronic injury. This article will review wound healing physiology and discuss the role of normal flora in the skin and chronic wounds.

Probiotics, Photobiomodulation, and Disease Management: Controversies and Challenges

In recent decades, researchers around the world have been studying intensively how micro-organisms that are present inside living organisms could affect the main processes of life, namely health and pathological conditions of mind or body. They discovered a relationship between the whole microbial colonization and the initiation and development of different medical disorders. Besides already known probiotics, novel products such as postbiotics and paraprobiotics have been developed in recent years to create new non-viable micro-organisms or bacterial-free extracts, which can provide benefits to the host with additional bioactivity to probiotics, but without the risk of side effects. The best alternatives in the use of probiotics and postbiotics to maintain the health of the intestinal microbiota and to prevent the attachment of pathogens to children and adults are highlighted and discussed as controversies and challenges. Updated knowledge of the molecular and cellular mechanisms involved in the balance between microbiota and immune system for the introspection on the gut-lung-brain axis could reveal the latest benefits and perspectives of applied photobiomics for health. Multiple interconditioning between photobiomodulation (PBM), probiotics, and the human microbiota, their effects on the human body, and their implications for the management of viral infectious diseases is essential. Coupled complex PBM and probiotic interventions can control the microbiome, improve the activity of the immune system, and save the lives of people with immune imbalances. There is an urgent need to seek and develop innovative treatments to successfully interact with the microbiota and the human immune system in the coronavirus crisis. In the near future, photobiomics and metabolomics should be applied innovatively in the SARS-CoV-2 crisis (to study and design new therapies for COVID-19 immediately), to discover how bacteria can help us through adequate energy biostimulation to combat this pandemic, so that we can find the key to the hidden code of communication between RNA viruses, bacteria, and our body.

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.

The role of topical probiotics on wound healing: A review of animal and human studies

Pathogenic, opportunistic, and commensal bacterial coexist in the intestinal tract, and imbalances among these strains have been linked to systemic inflammation and a variety of disease states. Similarly, human skin plays an important role as an interface between the body and the environment with an estimated 1 billion microbes per square centimetres. Skin microbiome fluctuations that cause increases in pathologic bacteria, either because of individual and/or environmental factors, can lead to disease states at the skin level ranging from inflammatory conditions to infections. As wounds are inherently associated with perturbations in the local microflora due to injury and activation of the immune responses, the addition of topical probiotics could be a means to prevent infection, regulate inflammation, and potentially augment healing. The goal of this review is to analyse the impact the skin microbiome has on cutaneous wound healing with a focus on developing proposed treatment algorithms and support for their therapeutic potential.