Impact of prebiotics and probiotics on skin health

A two-center randomized controlled trial of a repairing mask as an adjunctive treatment for mild to moderate rosacea

OBJECTIVE

To investigate the efficacy and safety of a repairing mask as an adjunctive treatment for skin barrier maintenance of mild to moderate rosacea.

METHODS

Patients with rosacea were recruited in this dual center randomized controlled trial from November 2019 to December 2021. A total of 64 patients were included and randomized into two groups at a ratio of 3:1 into a mask group (n = 47) and a control group (n = 17). Patients in the mask group received treatment with Dr. Yu Centella asiatica repairing facial mask three times weekly for a duration of 6 weeks. All participants were instructed to continue their regimen of 50 mg oral minocycline twice daily and to apply Dr. Yu Intensive Hydrating Soft Cream twice daily. The primary endpoint of this study was the Investigator Global Assessment (IGA) score.

RESULTS

A total of 54 patients completed this trial, with 41 in the mask group and 13 in the control group. After using this facial mask for 3 and 6 weeks, the IGA, facial skin dryness, facial flushing, and severity of skin lesion in the mask group showed significantly improvement (p < 0.05). Moreover, the change in the delta degree of skin flushing was significantly higher than that in the control group (p = 0.037). Throughout the study, no adverse events were reported in either group of participants.

CONCLUSION

The Dr. Yu Centella asiatica repairing facial mask, as an adjunctive treatment of rosacea, appears to effectively repair and protect the skin barrier, alleviate cutaneous symptoms of rosacea, and is both efficacious and safe for patient use.

Immunological aspects of probiotics for improving skin diseases: Influence on the Gut-Brain-Skin Axis

The interplay between gut microbiota and human health, both mental and physical, is well-documented. This connection extends to the gut-brain-skin axis, linking gut microbiota to skin health. Recent studies have underscored the potential of probiotics and prebiotics to modulate gut microbiota, supported by in vivo and clinical investigations. In this comprehensive review, we explore the immunological implications of probiotics in influencing the gut-skin axis for the treatment and prevention of skin conditions, including psoriasis, acne, diabetic ulcers, atopic dermatitis, and skin cancer. Our analysis reveals that probiotics exert their effects by modulating cytokine production, whether administered orally or topically. Probiotics bolster skin defenses through the production of antimicrobial peptides and the induction of keratinocyte differentiation and regeneration. Yet, many questions surrounding probiotics remain unanswered, necessitating further exploration of their mechanisms of action in the context of skin diseases.

Association between gut microbiota and pan-dermatological diseases: a bidirectional Mendelian randomization research

Background

Gut microbiota has been associated with dermatological problems in earlier observational studies. However, it is unclear whether gut microbiota has a causal function in dermatological diseases.

Methods

Thirteen dermatological diseases were the subject of bidirectional Mendelian randomization (MR) research aimed at identifying potential causal links between gut microbiota and these diseases. Summary statistics for the Genome-Wide Association Study (GWAS) of gut microbiota and dermatological diseases were obtained from public datasets. With the goal of evaluating the causal estimates, five acknowledged MR approaches were utilized along with multiple testing corrections, with inverse variance weighted (IVW) regression serving as the main methodology. Regarding the taxa that were causally linked with dermatological diseases in the forward MR analysis, reverse MR was performed. A series of sensitivity analyses were conducted to test the robustness of the causal estimates.

Results

The combined results of the five MR methods and sensitivity analysis showed 94 suggestive and five significant causal relationships. In particular, the genus Eubacterium_fissicatena_group increased the risk of developing psoriasis vulgaris (odds ratio [OR] = 1.32, pFDR = 4.36 × 10-3), family Bacteroidaceae (OR = 2.25, pFDR = 4.39 × 10-3), genus Allisonella (OR = 1.42, pFDR = 1.29 × 10-2), and genus Bacteroides (OR = 2.25, pFDR = 1.29 × 10-2) increased the risk of developing acne; and the genus Intestinibacter increased the risk of urticaria (OR = 1.30, pFDR = 9.13 × 10-3). A reverse MR study revealed insufficient evidence for a significant causal relationship. In addition, there was no discernible horizontal pleiotropy or heterogeneity.

Conclusion

This study provides novel insights into the causality of gut microbiota in dermatological diseases and therapeutic or preventive paradigms for cutaneous conditions.

The Plethora of Microbes with Anti-Inflammatory Activities

Inflammation, which has important functions in human defense systems and in maintaining the dynamic homeostasis of the body, has become a major risk factor for the progression of many chronic diseases. Although the applied medical products alleviate the general status, they still exert adverse effects in the long term. For this reason, the solution should be sought in more harmless and affordable agents. Microorganisms offer a wide range of active substances with anti-inflammatory properties. They confer important advantages such as their renewable and inexhaustible nature. This review aims to provide the most recent updates on microorganisms of different types and genera, being carriers of anti-inflammatory activity.

Diet and skin health: The good and the bad

The skin protects humans from pathogens, ultraviolet light, chemicals, mechanical, thermal, and physical injuries as well as hazardous substances. Other important roles of the skin include the regulation of several important physiological processes of the body, sensing stimuli, synthesis of vitamin D, and immune surveillance. However, aging, diseases and environmental conditions significantly change the skin's behavior and functioning. The treatment and prevention strategies for various skin diseases especially photoaging usually include topical treatment with medical cosmetology, active ingredients and other physical means of photoprotection. In recent times, however, there is an increasing consciousness about the role of diet and nutrition in skin health with certain dietary components emerging as an adequate alternative approach to alleviate and prevent both endogenous and exogenous aging symptoms. Therefore, this narrative review uniquely discusses the basic structure of the skin and also addresses common dermatological signs of damaged skin, the impacts of unhealthy diet habits on the skin, and the beneficial effects of some healthy diet habits on skin health. The information and data were collated from various literature databases and resources such as Science Direct, PubMed, Wiley, Springer, Taylor and Francis, Inflibnet, Scopus, Google, and Google Scholar using relevant keywords Medical Subject Headings (MeSH). In conclusion, diet and nutrition play essential roles in the optimum functioning of the human body, including the skin. Thus, certain diet habits such as less water intake, high-fat diet, refined sugar, and certain food additives are unhealthy and harmful to the skin while alternative healthy diet habits such as adequate water intake; consumption of antioxidants and polyphenolic-rich fruits, vegetables, nuts, and legumes; a low glycemic index diet; probiotics; and phytoestrogens should be adopted to enhance skin health.

Dietary Influences on Skin Health in Common Dermatological Disorders

The role of diet in the development of skin disorders is well-established, with nutritional deficiency often identified as a risk factor for skin diseases. Imbalances in the skin can be caused by nutritional deficiencies, excessive intake, insufficient nutrients, and hazardous ingredients. Patients frequently inquire about the impact of dietary patterns on skin health when consulting dermatologists in clinical settings. Simultaneously, the popularity of using nutritional supplements containing vitamins, minerals, and nutraceutical blends has been on the rise. It is crucial for dermatologists, primary care physicians, and other healthcare providers to be acquainted with evidence-based dietary interventions, distinguishing them from those that are more market-driven than truly efficacious. This review explores the modification of diet, encompassing both dietary exclusion and supplementation, as a therapeutic approach for conditions such as psoriasis, atopic dermatitis, bullous disease, vitiligo, and alopecia areata. A comprehensive literature search, utilizing the PubMed/Medline, Google Scholar, and Medscape databases, was conducted to investigate the relationship between each nutrient and various inflammatory skin diseases. The findings emphasize the significance of a well-balanced and thoughtfully planned diet in supplying adequate amounts of proteins, vitamins, and minerals to support optimal skin health. Additionally, this comprehensive review navigates through various dietary recommendations, offering insights into their multifaceted impacts on the immune system, gut microbiome, and skin health. The goal is to pave the way for informed and targeted dietary interventions for individuals dealing with food allergies and associated skin conditions.

Exploring the polarization of M1 and M2 macrophages in the context of skin diseases

Macrophages are critical components of the immune system and play vital roles in pathogen defense, immune regulation, and tissue repair. These cells exhibit different polarization states depending on environmental signals, and the M1/M2 paradigm is a useful tool for comprehending these states. This review article comprehensively presents the underlying mechanisms of M1 and M2 macrophage polarization and examines their polarization in various skin diseases. Additionally, this paper discusses therapeutic strategies that target M1 and M2 macrophage polarization in skin diseases. A more profound understanding of macrophage polarization in skin diseases could provide valuable insights for the development of innovative therapeutic strategies.

A Novel Handrub Tablet Loaded with Pre- and Post-Biotic Solid Lipid Nanoparticles Combining Virucidal Activity and Maintenance of the Skin Barrier and Microbiome

OBJECTIVE

This study aimed to develop a holobiont tablet with rapid dispersibility to provide regulation of the microbiota, virucidal activity, and skin barrier protection.

METHODS

A 23 factorial experiment was planned to define the best formulation for the development of the base tablet, using average weight, hardness, dimensions, swelling rate, and disintegration time as parameters to be analyzed. To produce holobiont tablets, the chosen base formulation was fabricated by direct compression of prebiotics, postbiotics, and excipients. The tablets also incorporated solid lipid nanoparticles containing postbiotics that were obtained by high-pressure homogenization and freeze-drying. The in vitro virucidal activity against alpha-coronavirus particles (CCoV-VR809) was determined in VERO cell culture. In vitro analysis, using monolayer cells and human equivalent skin, was performed by rRTq-PCR to determine the expression of interleukins 1, 6, 8, and 17, aquaporin-3, involucrin, filaggrin, FoxO3, and SIRT-1. Antioxidant activity and collagen-1 synthesis were also performed in fibroblast cells. Metagenomic analysis of the skin microbiome was determined in vivo before and after application of the holobiont tablet, during one week of continuous use, and compared to the use of alcohol gel. Samples were analyzed by sequencing the V3-V4 region of the 16S rRNA gene.

RESULTS

A handrub tablet with rapid dispersibility was developed for topical use and rinse off. After being defined as safe, the virucidal activity was found to be equal to or greater than that of 70% alcohol, with a reduction in interleukins and maintenance or improvement of skin barrier gene markers, in addition to the reestablishment of the skin microbiota after use.

CONCLUSIONS

The holobiont tablets were able to improve the genetic markers related to the skin barrier and also its microbiota, thereby being more favorable for use as a hand sanitizer than 70% alcohol.

Innovative Approaches for Maintaining and Enhancing Skin Health and Managing Skin Diseases through Microbiome-Targeted Strategies

The skin microbiome is crucial in maintaining skin health, and its disruption is associated with various skin diseases. Prebiotics are non-digestible fibers and compounds found in certain foods that promote the activity and growth of beneficial bacteria in the gut or skin. On the other hand, live microorganisms, known as probiotics, benefit in sustaining healthy conditions when consumed in reasonable quantities. They differ from postbiotics, which are by-product compounds from bacteria that release the same effects as their parent bacteria. The human skin microbiome is vital when it comes to maintaining skin health and preventing a variety of dermatological conditions. This review explores novel strategies that use microbiome-targeted treatments to maintain and enhance overall skin health while managing various skin disorders. It is important to understand the dynamic relationship between these beneficial microorganisms and the diverse microbial communities present on the skin to create effective strategies for using probiotics on the skin. This understanding can help optimize formulations and treatment regimens for improved outcomes in skincare, particularly in developing solutions for various skin problems.

Effects of the combination of chitosan and Acinetobacter KU011TH on the growth and health performances and disease resistance of juvenile hybrid catfish (Clarias gariepinus × C. macrocephalus)

Aquatic animal health management has become a crucial component in the goal of increasing catfish aquaculture productivity. Additionally, hybrid catfish (Clarias gariepinus × C. macrocephalus) has been promoted as a highly profitable freshwater fish in Asia. Interestingly, the crucial diseases induced by Aeromonas hydrophila have been reported to greatly impede catfish production. To overcome this challenge, the aim was to investigate the effects of the oral administration of potentially synbiotic chitosan (CH) and Acinetobacter KU011TH (AK) on the growth performance, immunological responses, and disease resistance of hybrid catfish against A. hydrophila. The control group was fed a basal diet (A), the diet fed to treatment group B was supplemented with 20 mL of CH/kg diet (B), and the experimental feed fed to groups C-D was mixed with 1 × 108, 1 × 109 and 1 × 1010 CFU/mL AK coated with 20 mL of CH/kg diet. Five different groups of juvenile hybrid catfish were continuously fed the 5 formulated feeds for 4 weeks. The results revealed that all tested feeds did not significantly enhance the hybrid catfish's average daily gain, specific growth rate, feed conversion ratio, hematocrit and erythrocyte counts. Interestingly, the application of CH and AK significantly increased the leukocyte counts, respiratory burst, lysozyme activity, alternative complement pathway hemolytic activity, and bactericidal activity (P < 0.05). The expression levels of the immune-related genes in the whole blood, head kidney, and spleen were significantly increased after CH-AK application (P < 0.05), but this finding was not observed in the liver (P > 0.05). Additionally, after 14 days of A. hydrophila peritoneal injection, the fish in group C showed significantly higher survival rates of approximately 70.0 % compared with the control fish in groups B, D, and E (52.5 %, 40.0 %, 45.0 %, and 45.0 %, respectively) (P < 0.05). These results collectively suggest that short-term application of the diet fed to group C effectively boosted the immune responses and disease resistance of hybrid catfish against A. hydrophila.

Emollients "Plus" are Beneficial in Both the Short and Long Term in Mild Atopic Dermatitis

Introduction

Atopic dermatitis (AD) is a chronic relapsing disease with a pathophysiology including skin barrier damage, microbiome disbalance and inflammation. Classically, emollients maintaining a healthy microbiome are recommended as the basis of any AD severity management.

Objective

To assess the benefit of a light balm containing vitamin E, tocopherol and glycerine and enriched with Aqua posae filiformis and microresyl (Emollient+) in subjects with mild AD over a period of 168 days.

Materials and Methods

For this open-label study, subjects above 3 years of age with mild and stable AD for at least 6 months before inclusion and with a SCORAD score of <25 were eligible. Assessments took place at baseline, D14, D28, D84 and D168, and included SCORAD, flare frequency, severity of clinical signs and symptoms, skin hydration status using a Corneometer and local tolerance. QoL was assessed using the DLQI or CDLQI questionnaire. Subjects used Emollient+ at least once daily.

Results

Overall, 56 subjects were included in this study. The mean age was 25.0±20.0 years (45% children); 69.6% were females. Except for erythema in the paediatric population, all clinical parameters had significantly (all p < 0.05) improved at D28. At D168, SCORAD, signs and symptoms had significantly (all p < 0.05) improved in the global, adult and paediatric population at D168 compared to baseline. So did flares, skin hydration and QoL. The regimen was very well tolerated.

Conclusion

Emollient+ is highly beneficial and well tolerated in mild AD with early benefits in improving AD signs and symptoms and skin hydration as well as the QoL of subjects as soon as D28.

Clinicaltrialsgov identifier

NCT05783453.

The role of probiotics in tissue engineering and regenerative medicine

Tissue engineering and regenerative medicine (TERM) as an emerging field is a multidisciplinary science and combines basic sciences such as biomaterials science, biology, genetics and medical sciences to achieve functional TERM-based products to regenerate or replace damaged or diseased tissues or organs. Probiotics are useful microorganisms which have multiple effective functions on human health. They have some immunomodulatory and biocompatibility effects and improve wound healing. In this article, we describe the latest findings on probiotics and their pro-healing properties on various body systems that are useable in regenerative medicine. Therefore, this review presents a new perspective on the therapeutic potential of probiotics for TERM.

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.

Multi-omic approach to decipher the impact of skincare products with pre/postbiotics on skin microbiome and metabolome

Introduction

Although pre/pro/postbiotics have become more prevalent in dermatologic and cosmetic fields, the mode of action when topically applied is largely unknown. A multi-omic approach was applied to decipher the impact of the skincare products with pre/postbiotics on skin microbiome and metabolome.

Methods

Subjects with dry skin applied a body wash and body lotion with or without pre/postbiotics for 6 weeks. Skin hydration was measured at baseline, 3 and 6 weeks. Skin swabs were collected for 16S rRNA gene sequencing, metagenomics and metabolomics analysis.

Results

Skin hydration significantly increased in both groups. The prebiotic group significantly reduced opportunistic pathogens, e.g., Pseudomonas stutzeri and Sphingomonas anadarae, and increased the commensals, e.g., Staphylococcus equorum, Streptococcus mitis, Halomonas desiderata. Bacterial sugar degradation pathways were enriched in the prebiotic group, while fatty acid biosynthesis pathways were reduced in control. The changes on skin metabolome profiles by the products were more prominent. The prebiotic group performed greater modulation on many clinically-relevant metabolites compared to control. Correlation analysis showed H. desiderata and S. mitis positively correlated with skin hydration, P. stutzeri and S. anadarae negatively correlated with the metabolites that are positively associated with skin hydration improvement.

Conclusion

This holistic study supported a hypothesis that the pre/postbiotics increased skin hydration through the modulation of skin microbiome, metabolic pathways and metabolome.

Exploring the Potential of Extracts from Sloanea medusula and S. calva: Formulating Two Skincare Gels with Antioxidant, Sun Protective Factor, and Anti-Candida albicans Activities

Sloanea is a plant genus, native to tropical regions, used in medicinal practices for its anti-inflammatory properties. This study aimed to determine the antioxidant activity, sun protective factor (SPF), and antifungal of extracts obtained from two species of Sloanea and to develop extract-based gels with antioxidants, photoprotective, and anti-Candida albicans effects. Ethanolic extracts from S. medusula and S. calva collected in Chocó, Colombia, were used for antioxidant activity and SPF determination using the DPPH assay and the Mansur equation, respectively. Extracts were characterized using HPLC-MS and used to prepare the gels. The viscosity of the extract-based gels was evaluated using an MCR92 rheometer. In addition, the anti-Candida activity of extracts against five yeasts and anti-C. albicans of gels were evaluated following the Clinical and Laboratory Standards Institute M27, 4th Edition. High DPPH radical scavenging activity (42.4% and 44.7%) and a high SPF value (32.5 and 35.4) were obtained for the extracts of S. medusula and S. calva, respectively. Similarly, extract-based gels showed significant DPPH radical scavenging activity of 54.5% and 53.0% and maximum SPF values of 60 and 57. Extract from S. medusula showed an important antifungal activity against C. albicans (minimal inhibitory concentration (MIC) of 2 µg/mL). In contrast, S. calva extract was active against C. krusei, C. albicans (MIC of 2 µg/mL) and C. tropicalis (MIC of 4 µg/mL). Sloanea medusula gel (0.15%) exhibited an important C. albicans growth inhibition (98%), while with S. calva gel (0.3%) growth inhibition was slightly lower (76%). Polyphenolic and triterpenoid compounds were tentatively identified for S. medusula and S. calva, respectively. Both extracts can be considered promising sources for developing photoprotective gels to treat skin infections caused by C. albicans.

Oral Supplementation with Algal Sulphated Polysaccharide in Subjects with Inflammatory Skin Conditions: A Randomised Double-Blind Placebo-Controlled Trial and Baseline Dietary Differences

We examined the effect of a dietary seaweed extract-sulfated xylorhamnoglucuronan (SXRG84)-on individuals with inflammatory skin conditions. A subgroup analysis of a larger trial was undertaken, where 44 participants with skin conditions were enrolled in a double-blind placebo-controlled crossover design. Subjects ingested either SXRG84 extract (2 g/day) for six weeks and placebo for six weeks, or vice versa. At baseline, six- and twelve-weeks inflammatory markers and the gut microbiota were assessed, as well as skin assessments using the dermatology quality of life index (DQLI), psoriasis area severity index (PASI) and visual analogue scales (VAS). There were significant differences at weeks six and twelve for pro-inflammatory cytokines IFN-γ (p = 0.041), IL-1β (p = 0.030), TNF-α (p = 0.008) and the anti-inflammatory cytokine IL-10 (p = 0.026), determined by ANCOVA. These cytokines were all significantly higher at six weeks post placebo compared to twelve weeks post placebo followed by SXRG84 treatment. A total of 23% of participants reported skin improvements, as measured by VAS (mean difference 3.1, p = 0.0005) and the DQLI score (mean difference -2.0, p = 0.049), compared to the 'non-responders'. Thus, the ingestion of SXRG84 for 6 weeks reduced inflammatory cytokines, and a subset of participants saw improvements.

Anti-Inflammation and Anti-Melanogenic Effects of Maca Root Extracts Fermented Using Lactobacillus Strains

Maca is a well-known biennial herb with various physiological properties, such as antioxidant activity and immune response regulation. In this study, the antioxidant, anti-inflammatory, and anti-melanogenic effects of fermented maca root extracts were investigated. The fermentation was carried out using Lactobacillus strains, such as Lactiplantibacillus plantarum subsp. plantarum, Lacticaseibacillus rhamnosus, Lacticaseibacillus casei, and Lactobacillus gasseri. In RAW 264.7 cells, the non-fermented maca root extracts increased the secretion of nitric oxide (NO), an inflammatory mediator, in a dose-dependent manner. In contrast, the fermented extracts showed considerably lower NO secretion than the non-fermented extracts at concentrations of 5% and 10%. This indicates the effective anti-inflammatory effects of fermented maca. The fermented maca root extracts also inhibited tyrosinase activity, melanin synthesis, and melanogenesis by suppressing MITF-related mechanisms. These results show that fermented maca root extracts exhibit higher anti-inflammatory and anti-melanogenesis effects than non-fermented maca root extracts. Thus, maca root extracts fermented using Lactobacillus strains have the potential to be used as an effective cosmeceutical raw material.

Microbiota dysbiosis and myasthenia gravis: Do all roads lead to Rome?

Dysregulated immune system with a failure to recognize self from non-self-antigens is one of the common pathogeneses seen in autoimmune diseases. The complex interplay of genetic and environmental factors is important for the occurrence and development of the disease. Among the environmental factors, disturbed gut microbiota (gut dysbiosis) has recently attracted particular attention, especially with advancement in human microbiome research. Although the alterations in microbiota have been seen in various autoimmune diseases, including those of nervous system, there is paucity of information on neuromuscular system diseases. Myasthenia gravis (MG) is one such rare autoimmune disease of neuromuscular junction, and is caused by generation of pathogenic autoantibodies to components of the postsynaptic muscle endplate. In the recent years, accumulating evidences have endorsed the key role of host microbiota, particularly those of gut, in the pathogenesis of MG. Differential microbiota composition, characterized by increased abundance of Fusobacteria, Bacteroidetes, and Proteobacteria, and decreased abundance of Actinobacteria and Firmicutes, has been seen in MG patients in comparison to healthy subjects. Disturbance of microbiota composition, particularly reduced ratio of Firmicutes/Bacteroidetes, alter the gut permeability, subsequently triggering the immunological response. Resultant reduction in levels of short chain fatty acids (SCFAs) is another factor contributing to the immunological response in MG patients. Modulation of gut microbiota via intervention of probiotics, prebiotics, synbiotics, postbiotics (metabiotics), and fecal microbiota transplantation (FMT) is considered to be the futuristic approach for the management of MG. This review summarizes the role of gut microbiota and their metabolites (postbiotics) in the progression of MG. Also, various bacteriotherapeutic approaches involving gut microbiota are discussed for the prevention of MG progression.

Urbanisation and its Associated Factors Affecting Human Gut Microbiota: Where are we Heading to?

ContextThe continuous rise in urbanisation and its associated factors have been reflected in the structure of the human gut ecosystem.ObjectiveThe main focus of the review is to discuss and summarise the major risk factors associated with urbanisation that affects human gut microbiota thus affecting human health.MethodsMultiple medical literature databases, namely PubMed, Google, Google Scholar, and Web of Science were used to find relevant materials for urbanization and its major factors affecting human gut microbiota/microbiome. Both layman and Medical Subject Headings (MeSH) terms were used in the search. Due to the scarcity of the data, no limitation was set on the publication date. Relevant material in the English language which includes case reports, chapters of books, journal articles, online news reports and medical records was included in this review.ResultsBased on the data discussed in the review, it is quite clear that urbanisation and its associated factors have long-standing effects on the human gut microbiota that result in alterations of gut microbial diversity and composition. This is a matter of serious concern as chronic inflammatory diseases are on the rise in urbanised societies.ConclusionA better understanding of the factors associated with urbanisation will help us to identify and implement new biological and social approaches to prevent and treat diseases and improve health globally by deepening our understanding of these relationships and increasing studies across urbanisation gradients.HIGHLIGHTSHuman gut microbiota has been linked to almost every important function, including metabolism, intestinal homeostasis, immune system, biosynthesis of vitamins, brain processes, and its behaviour.However, dysbiosis i.e., alteration in the composition and diversity of gut microbiota is associated with the pathogenesis of many chronic conditions.In the 21st century, urbanisation represents a major demographic shift in developed and developing countries.During this period of urbanisation, humans have been exposed to many environmental exposures, all of which have led to the dysbiosis of human gut microbiota.The main focus of the review is to discuss and summarize the major risk factors associated with urbanisation and how it affects the diversity and composition of gut microbiota which ultimately affects human health.

Analysis of cutaneous bacterial microbiota of Thai patients with seborrheic dermatitis

Seborrheic dermatitis (SD) is a chronic inflammatory skin condition that occurs in body areas that contain profuse sebaceous glands. Skin microbiota are diverse across ethnic groups and its dysbiosis has been implicated in the pathogenesis of SD. Here, we reported the contribution of cutaneous bacterial microbiota to SD in the Thai population. Healthy individuals and patients with scalp SD were recruited into the study. Normal skin, scalp skin lesion (SL) and non-lesion sites (SNL) samples were collected using a tape stripping method and next-generation sequencing of 16S rRNA for microbiome analysis. Although bacterial diversity in all sample groups was not statistically different, a population of bacteria commonly found on skin of scalp showed signs of dysbiosis. Apart from the reduction of Corynebacterium spp., SD-specific microbiota was dominated by Firmicutes at taxa level and Pseudomonas spp., Staphylococcus spp. and Micrococcus spp. at genus level. The dysbiosis of the skin microbiota in SD was specifically described as an alteration of bacteria populations commonly found on scalp skin, implying that managing and controlling the cutaneous bacterial microbiome can alleviate and prevent SD and pave the way for the development of new SD treatments.

Probiotic growth in skin-like conditions

Although probiotics' main known effects are in the digestive system, over the last years several benefits that come from their topical use, have been investigated. Several studies have reported beneficial effects on different skin disorders, such as atopic dermatitis, acne, eczema, psoriasis, wound healing, skin aging and reactive skin. Their main action is assigned to the inhibition of skin colonization by pathogens. In this work, the growths of three probiotic strains were evaluated in the presence of abiotic factors similar to those found in skin, namely, UV radiation, temperature, pH, NaCl and fatty acids. Lactobacillus rhamnosus showed increased growth under the pH of 6, but no differences in its growth were found for the various NaCl concentrations tested. Lactobacillus delbrueckii increased the number of bacterial cells in 88.8% when grown in 10 mM NaCl concentration, while Propioniferax innocua showed increased growth at 45 °C. All tested probiotic bacteria were able to grow under skin-like conditions. However, L. rhamnosus was the probiotic that showed the best results. The results obtained in this study indicate that the used probiotics may be beneficial in the treatment of skin diseases, since they are able to successfully thrive in skin-like conditions.

Advances in the human skin microbiota and its roles in cutaneous diseases

Skin is the largest organ in the human body, and the interplay between the environment factors and human skin leads to some skin diseases, such as acne, psoriasis, and atopic dermatitis. As the first line of human immune defense, skin plays significant roles in human health via preventing the invasion of pathogens that is heavily influenced by the skin microbiota. Despite being a challenging niche for microbes, human skin is colonized by diverse commensal microorganisms that shape the skin environment. The skin microbiota can affect human health, and its imbalance and dysbiosis contribute to the skin diseases. This review focuses on the advances in our understanding of skin microbiota and its interaction with human skin. Moreover, the potential roles of microbiota in skin health and diseases are described, and some key species are highlighted. The prevention, diagnosis and treatment strategies for microbe-related skin diseases, such as healthy diets, lifestyles, probiotics and prebiotics, are discussed. Strategies for modulation of skin microbiota using synthetic biology are discussed as an interesting venue for optimization of the skin-microbiota interactions. In summary, this review provides insights into human skin microbiota recovery, the interactions between human skin microbiota and diseases, and the strategies for engineering/rebuilding human skin microbiota.

Psoriasis: Interplay between dysbiosis and host immune system

With advancement in human microbiome research, an increasing number of scientific evidences have endorsed the key role of both gut and skin microbiota in the pathogenesis of psoriasis. Microbiome dysbiosis, characterized by altered diversity and composition, as well as rise of pathobionts, have been identified as possible triggers for recurrent episodes of psoriasis. Mechanistically, gut dysbiosis leads to "leaky gut syndrome" via disruption of epithelial bilayer, thereby, resulting in translocation of bacteria and other endotoxins to systemic circulation, which in turn, results in inflammatory response. Similarly, skin dysbiosis disrupts the cutaneous homeostasis, leading to invasion of bacteria and other pathogens to deeper layers of skin or even systemic circulation further enhanced by injury caused by pruritus-induced scratching, and elicit innate and adaptive inflammation. The present review explores the correlation of both skin and gut microbiota dysbiosis with psoriasis. Also, the studies highlighting the potential of bacteriotherapeutic approaches including probiotics, prebiotics, metabiotics, and fecal microbiota transplantation for the management of psoriasis have been discussed.

Effects of short chain fructo-oligosaccharides on selected skin bacteria

The human skin microbiota plays a key role in the maintenance of healthy skin, ensuring protection and biological barrier by competing with pathogens and by closely communicating with the immune system. The development of approaches which preserve or restore the skin microbiota represents a novel target for skincare applications. Prebiotics could be applied to balance almost any microbial community to achieve advantageous effects. However, information about their effectiveness as skin microbiota modulators is limited. The objective of the current study was to evaluate the effects of short chain fructo-oligosaccharides (scFOS) from sugar beet (DP 3-5), well-recognised prebiotics, on some representative bacterial strains of the skin microbiota. We measured the growth and competitive activity of these specific bacteria for the use of scFOS as energy source in minimal medium and in a reconstructed human epithelium (RHE) in vitro model. In minimal growth medium, scFOS promoted and sustained the growth of Staphylococcus epidermidis up to 24 h, considered a beneficial skin commensal bacterium, while inhibiting both Cutibacterium acnes and Staphylococcus aureus growth, regarded as opportunistic pathogens. S. epidermidis showed the highest colonization potential and 1% scFOS was effective in shifting the competition in favour of S. epidermidis with respect to C. acnes in the RHE model. This latter effect was observed following 24 h of exposure, suggesting a long-term effect of scFOS in a highly skin dynamic environment. Therefore, scFOS could be effectively implemented in skincare formulations for recovering skin microbiota homeostasis.

Amplicon-based sequencing and co-occurence network analysis reveals notable differences of microbial community structure in healthy and dandruff scalps

Background

Dandruff is a chronic, recurring, and common scalp problem that is caused by several etiopathogeneses with complex mechanisms. Management of this condition is typically achieved via antifungal therapies. However, the precise roles played by microbiota in the development of the condition have not been elucidated. Despite their omnipresence on human scalp little is known about the co-occurrence/co-exclusion network of cutaneous microbiota.

Results

We characterized the scalp and hair surface bacterial and fungal communities of 95 dandruff-afflicted and healthy individuals residing in China. The degree distributions of co-occurrence/co-exclusion network in fungi-bacteria and bacteria-bacteria were higher in the healthy group (P < 0.0001), whereas the betweenness values are higher in the dandruff group (P < 0.01). Meanwhile, the co-occurrence/co-exclusion network among fungi-fungi and fungi-bacteria showed that compared to the healthy group, the dandruff group had more positive links (P < 0.0001). In addition, we observed that Malassezia slooffiae, Malassezia japonica and Malassezia furfur, were more abundant in the dandruff group than in the healthy group. These microbiota were co-exclusion by either multiple bacterial genera or Malassezia sp. in healthy group. The lactic acid bacteria on the scalp and hair surface, especially the genera Lactobacillus and Lactococcus, exhibit a negative correlation with multiple bacterial genera on the scalp and hair surface. Lactobacillus plantarum and Pediococcus lactis isolated on the healthy human scalp can inhibit the growth of Staphylococcus epidermidis in vitro.

Conclusions

We showed that microbial networks on scalp and hair surface with dandruff were less integrated than their healthy counterparts, with lower node degree and more positive and stronger links which were deemed to be unstable and may be more susceptible to environmental fluctuations. Lactobacillus bacteria have extensive interactions with other bacteria or fungi in the scalp and hair surface micro-ecological network and can be used as targets for improving scalp health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08534-4.

Anti-Melanogenic and Antioxidant Effects of Cell-Free Supernatant from Lactobacillus gasseri BNR17

In recent years, there has been considerable interest in the use of cell-free supernatant of probiotics culture for nutritional and functional applications. In this study, we investigated the effect of the cell-free supernatant from Lactobacillus gasseri BNR17 (CFS) on anti-melanogenesis and reducing oxidative stress in B16-F10 murine melanoma cells and HaCaT human keratinocytes. Treatment with CFS significantly inhibited the production of extracellular and intracellular melanin without cytotoxicity during melanogenesis induced by the α-MSH in B16-F10 cells. The CFS dramatically reduced tyrosinase activity and the melanogenesis-related gene expression. Further, it showed antioxidative effects in a dose-dependent manner in DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assays and significantly increased the mRNA levels of HO-1 and CAT in HaCaT cells. Furthermore, the CFS increased HO-1 and anti-oxidative-related gene expression during H2O2-induced oxidative stress in HaCaT cells. Together, this study suggests that the CFS reduces hyperpigmentation and inhibits oxidative stress, and thus can be used as a potential skincare product in the future.

Cotton and Flax Textiles Leachables Impact Differently Cutaneous Staphylococcus aureus and Staphylococcus epidermidis Biofilm Formation and Cytotoxicity

Bacteria can bind on clothes, but the impacts of textiles leachables on cutaneous bacteria remain unknown. Here, we studied for the first time the effects of cotton and flax obtained through classical and soft ecological agriculture on the representatives S. aureus and S. epidermidis bacteria of the cutaneous microbiota. Crude flax showed an inhibitory potential on S. epidermidis bacterial lawns whereas cotton had no effect. Textile fiber leachables were produced in bacterial culture media, and these extracts were tested on S. aureus and S. epidermidis. Bacterial growth was not impacted, but investigation by the crystal violet technique and confocal microscopy showed that all extracts affected biofilm formation by the two staphylococci species. An influence of cotton and flax culture conditions was clearly observed. Flax extracts had strong inhibitory impacts and induced the formation of mushroom-like defense structures by S. aureus. Conversely, production of biosurfactant by bacteria and their surface properties were not modified. Resistance to antibiotics also remained unchanged. All textile extracts, and particularly soft organic flax, showed strong inhibitory effects on S. aureus and S. epidermidis cytotoxicity on HaCaT keratinocytes. Analysis of flax leachables showed the presence of benzyl alcohol that could partly explain the effects of flax extracts.

In Vitro-In Vivo Correlation for the Antibacterial Effect of Lactiplantibacillus plantarum as a Topical Healer for Infected Burn Wound

Difficulties in delivering antimicrobial agents to wound areas and emersion of multiple drug resistant organisms (MDROs) have converted managing burn infections into a complicated task in medicine. Probiotics emerged not only as a probable solution for burn infections but also as an accelerator in the healing process. The probability of in vitro-in vivo correlation (IVIVC) in probiotic activity leads to lower costs in finding new therapeutic options. Simulated wound fluid (SWF) was used to evaluate the antibacterial function of Lactiplantibacillus plantarum in wounds. The growth parameters in SWF were evaluated using a logistic model to predict growth behavior in the wound area. In addition, probiotic antimicrobial activity and secretion of antibacterial substances in SWF were also studied. Data were used to select the initial dose and apply frequency for in vivo study. The wound models were infected by two main pathogens (Pseudomonas aeruginosa or Staphylococcus aureus). In vitro results showed less lag time associated with considerable acid production in SWF. In the following, secretion of antimicrobial substances and co-aggregation with pathogens became more important. The susceptibility of pathogens to these factors was different, and culture medium affected the yield of each factor involved in eliminating pathogens. Histological analysis and macroscopic examination of wounds revealed probiotics as effective as positive control or more. There were some differences in the antibacterial functions of probiotics in simulated and real wound environments. The in vitro effect of probiotics on removal of pathogens was not the same as the trend seen in vivo.

Microbiome and Probiotics in Acne Vulgaris—A Narrative Review

Acne vulgaris is a chronic disease characterised by the appearance of eruptions such as whiteheads, blackheads, pustules, papules, and cysts. Among factors that cause acne vulgaris are the abnormal keratinisation of the sebaceous canal, bacterial colonisation (Cutibacterium acnes), increased sebum production, genotypic factors, and hormonal disorders. Treatment is often long and tedious, and can lead to a reduction in quality of life and social isolation. The intestinal microbiota is greatly important in the formation of acne lesions. It is also responsible for the proper immunity of the organism. Acne is a disease that can be related to the condition of the digestive tract and its microbiome. Research shows that the use of probiotics may reduce skin eruptions. The probiotic supplementation and cosmetics markets are very dynamically developing. The use of internal supplementation and probiotic-containing cosmetics gives hope for the improvement of the skin condition of people with acne.

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.

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

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

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

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

Impact of gut microbiome on skin health: gut-skin axis observed through the lenses of therapeutics and skin diseases

The human intestine hosts diverse microbial communities that play a significant role in maintaining gut-skin homeostasis. When the relationship between gut microbiome and the immune system is impaired, subsequent effects can be triggered on the skin, potentially promoting the development of skin diseases. The mechanisms through which the gut microbiome affects skin health are still unclear. Enhancing our understanding on the connection between skin and gut microbiome is needed to find novel ways to treat human skin disorders. In this review, we systematically evaluate current data regarding microbial ecology of healthy skin and gut, diet, pre- and probiotics, and antibiotics, on gut microbiome and their effects on skin health. We discuss potential mechanisms of the gut-skin axis and the link between the gut and skin-associated diseases, such as psoriasis, atopic dermatitis, acne vulgaris, rosacea, alopecia areata, and hidradenitis suppurativa. This review will increase our understanding of the impacts of gut microbiome on skin conditions to aid in finding new medications for skin-associated diseases.

Antimicrobial loaded gum odina - gelatin based biomimetic spongy scaffold for accelerated wound healing with complete cutaneous texture

The main objective of this study was to assess the therapeutic activity of gum odina and gelatin based biomimetic scaffold which was previously established as an excellent wound dressing material. In the accelerated stability study, the changes in physicochemical properties were found to be negligible. The cytotoxicity studies were carried out in-vitro and the results showed that upto 90% of the cells remained viable in presence of the scaffold, confirming its biocompatibility. Moreover, results depicted the superior ability of the scaffold to promote cutaneous healing by increasing the rate of wound contraction (about 98%), granulation formation, collagen deposition and formation of an intact epidermis within 18 days. A satisfactory amount of hydroxyproline (240.2 ± 6.67 μg/100 mg tissue) in scaffold treated groups at 21 days ensured the significant deposition of collagen to re-epithelialization. Further it can be hypothesized that the controlled levels of antioxidant enzymes (SOD, CAT) to diminish the oxidative stress in the wounded sites were due to the innate antioxidant properties of both blank and drug loaded scaffold. These results strongly indicated that the prepared scaffolds have strong potential for biomedical applications and it may serve as promising candidate for the next generation of wound treatment systems.

The potential prebiotic effect of 2-Butyloctanol on the human axillary microbiome

OBJECTIVE

The human axilla is colonized by a wide array of microorganisms that contribute to the generation of body odour. Traditional antiperspirant/deodorant products are used to reduce perspiration in the axillary region and to treat or prevent the growth of bacteria in this region, thereby reducing or eliminating body odour. However, they may also compromise the axillary microbiome balance. The personal care industry has been seeking new ingredients, such as prebiotics or probiotics, to maintain a healthy balance of the skin microbiome by inhibiting odour-causing bacteria, whilst maintaining and promoting the growth of good bacteria. The aim of this study was to investigate the prebiotic effect of a skin-care ingredient, 2-butyloctanol, on the human axillary microbiome.

METHODS

An in vitro growth inhibition/promotion assay was performed to test whether 2-butyloctanol inhibited or promoted skin bacterial growth. The impact of 2-butyloctanol on the axillary microbiome was also investigated in a human clinical study using 16S rRNA gene sequencing.

RESULTS

In-vitro testing showed that 2-butyloctanol significantly inhibited the growth of corynebacteria at concentrations of 0.64%, 2.56% and 5.12%, whilst the growth of Staphylococcus epidermidis was maintained at the same concentrations. The impact of 2-butyloctanol on the axillary microbiome was also validated in a human clinical study. A deodorant roll-on product containing 3% of 2-butyloctanol significantly reduced the relative abundance of corynebacteria, whilst increasing the relative abundance of Staphylococcus and the ratio of Staphylococcus to corynebacteria after four weeks of application, whilst the placebo showed no significant change.

CONCLUSION

For the first time, it was demonstrated that 2-butyloctanol had a potential prebiotic effect on the human underarm microbiome in inhibiting odour-causing Corynebacterium, whilst maintaining and promoting skin-friendly Staphylococcus in both in-vitro and in-vivo studies. Therefore, 2-butyloctanol could be used as a potential prebiotic ingredient in personal care products for underarm microbiome protection.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Advantages of Hyaluronic Acid and Its Combination with Other Bioactive Ingredients in Cosmeceuticals

This study proposes a review on hyaluronic acid (HA) known as hyaluronan or hyaluronate and its derivates and their application in cosmetic formulations. HA is a glycosaminoglycan constituted from two disaccharides (N-acetylglucosamine and D-glucuronic acid), isolated initially from the vitreous humour of the eye, and subsequently discovered in different tissues or fluids (especially in the articular cartilage and the synovial fluid). It is ubiquitous in vertebrates, including humans, and it is involved in diverse biological processes, such as cell differentiation, embryological development, inflammation, wound healing, etc. HA has many qualities that recommend it over other substances used in skin regeneration, with moisturizing and anti-ageing effects. HA molecular weight influences its penetration into the skin and its biological activity. Considering that, nowadays, hyaluronic acid has a wide use and a multitude of applications (in ophthalmology, arthrology, pneumology, rhinology, aesthetic medicine, oncology, nutrition, and cosmetics), the present study describes the main aspects related to its use in cosmetology. The biological effect of HA on the skin level and its potential adverse effects are discussed. Some available cosmetic products containing HA have been identified from the brand portfolio of most known manufacturers and their composition was evaluated. Further, additional biological effects due to the other active ingredients (plant extracts, vitamins, amino acids, peptides, proteins, saccharides, probiotics, etc.) are presented, as well as a description of their possible toxic effects.

Bacterial Vaginosis: Effects on reproduction and its therapeutics

Bacterial Vaginosis (BV) is the most common vaginal infection. A large amount of evidence shows that the anatomical scope of BV's pathogenic effect is far beyond the lower reproductive tract. BV is closely related to adverse reproductive outcomes, which may be due to the infection of the vaginal flora ascending to the upper genital tract. In addition, the incidence of BV is relatively high in infertile women. The vaginal microbiome also plays an important role in women's health and diseases. For most women, the normal vaginal microbiota is dominated by Lactobacillus, which can maintain a healthy vaginal environment by producing lactic acid, H₂O₂ and bacteriocin, etc. BV is characterized by the imbalanced vaginal flora. It changes the acidic environment that is normally dominated by Lactobacillus, and causes an overgrowth of anaerobic and facultative anaerobic bacteria such as Gardnerella vaginalis and Atopobium vaginae. Studies have shown that bacterial infections in the vagina can spread to upper genital tract and cause adverse fertility outcome. Therefore, early diagnosis and therapeutics of symptomatic BV is helpful to improve the outcome of poor fertility.

Atopic dermatitis: Role of the skin barrier, environment, microbiome, and therapeutic agents

Atopic dermatitis (AD) is a chronic, inflammatory skin disorder characterized by eczematous and pruritic skin lesions. In recent decades, the prevalence of AD has increased worldwide, most notably in developing countries. The enormous progress in our understanding of the complex composition and functions of the epidermal barrier allows for a deeper appreciation of the active role that the skin barrier plays in the initiation and maintenance of skin inflammation. The epidermis forms a physical, chemical, immunological, neuro-sensory, and microbial barrier between the internal and external environment. Not only lesional, but also non-lesional areas of AD skin display many morphological, biochemical and functional differences compared with healthy skin. Supporting this notion, genetic defects affecting structural proteins of the skin barrier, including filaggrin, contribute to an increased risk of AD. There is evidence to suggest that natural environmental allergens and man-made pollutants are associated with an increased likelihood of developing AD. A compromised epidermal barrier predisposes the skin to increased permeability of these compounds. Numerous topical and systemic therapies for AD are currently available or in development; while anti-inflammatory therapy is central to the treatment of AD, some existing and novel therapies also appear to exert beneficial effects on skin barrier function. Further research on the skin barrier, particularly addressing epidermal differentiation and inflammation, lipid metabolism, and the role of bacterial communities for skin barrier function, will likely expand our understanding of the complex etiology of AD and lead to identification of novel targets and the development of new therapies.

Exploring the human hair follicle microbiome

Human hair follicles (HFs) carry complex microbial communities that differ from the skin surface microbiota. This likely reflects that the HF epithelium differs from the epidermal barrier in that it provides a moist, less acidic, and relatively ultraviolet light-protected environment, part of which is immune-privileged, thus facilitating microbial survival. Here we review the current understanding of the human HF microbiome and its potential physiological and pathological functions, including in folliculitis, acne vulgaris, hidradenitis suppurativa, alopecia areata and cicatricial alopecias. While reviewing the main human HF bacteria (such as Propionibacteria, Corynebacteria, Staphylococci and Streptococci), viruses, fungi and parasites as human HF microbiome constituents, we advocate a broad view of the HF as an integral part of the human holobiont. Specifically, we explore how the human HF may manage its microbiome via the regulated production of antimicrobial peptides (such as cathelicidin, psoriasin, RNAse7 and dermcidin) by HF keratinocytes, how the microbiome may impact on cytokine and chemokine release from the HF, and examine hair growth-modulatory effects of antibiotics, and ask whether the microbiome affects hair growth in turn. We highlight major open questions and potential novel approaches to the management of hair diseases by targeting the HF microbiome.

Shaping the Future of Probiotics and Prebiotics

Recent and ongoing developments in microbiome science are enabling new frontiers of research for probiotics and prebiotics. Novel types, mechanisms, and applications currently under study have the potential to change scientific understanding as well as nutritional and healthcare applications of these interventions. The expansion of related fields of microbiome-targeted interventions, and an evolving landscape for implementation across regulatory, policy, prescriber, and consumer spheres, portends an era of significant change. In this review we examine recent, emerging, and anticipated trends in probiotic and prebiotic science, and create a vision for broad areas of developing influence in the field.

Lactobacillus rhamnosus CGMCC 1.3724 (LPR) Improves Skin Wound Healing and Reduces Scar Formation in Mice

Skin wounds are an important clinical problem which affects millions of people worldwide. The search for new therapeutic approaches to improve wound healing is needed. The present study aimed to evaluate the effects of the oral treatment with the skin-related probiotics Lactobacillus johnsonii LA1 (LJ), L. paracasei ST11 (LP), and L. rhamnosus LPR (LR) in a model of excisional skin wounds in Swiss mice. The animals received daily oral gavage of PBS or 1 × 10⁷ colony-forming units of LJ, LP, or LR, singly, beginning just after the creation of wounds until euthanasia. Blood flow was evaluated by laser Doppler perfusion imaging. Myeloperoxidase and N-acetyl-β-D-glucosaminidase activities were used to assess the accumulation of neutrophils and macrophages, respectively. The wound tissue was also collected for histological analyses (H&E, Toluidine blue, and Picrosirius red staining). The macroscopic wound closure rate was faster only in mice treated with LR, but not with LJ and LP, when compared to mice treated with PBS. Histological evaluations showed that treatment with LR stimulated wound epithelization when compared to PBS. Further analyses showed that wounds from LR-treated mice presented a significant decrease in macrophage (p < 0.001) and mast cell (p < 0.001) infiltration, along with improved angiogenesis (p < 0.001) and blood flow (p < 0.01). Of note, collagen deposition and scarring were reduced in LR-treated mice when compared to PBS-treated mice. In conclusion, our results show that the oral treatment with Lactobacillus rhamnosus accelerates skin wound closure and reduces scar, besides to reducing inflammation and fibrogenesis and improving angiogenesis in the wounded skin.

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

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

Effect of oral administration of Triphala, a polyphenol-rich prebiotic, on scalp sebum in patients with scalp seborrhea a randomized clinical trial

BACKGROUND

Although there are various therapeutic options to control oily skin, they have potential side effects and limitations especially in long-term use. Pre/probiotics may have beneficial effects in atopic dermatitis' acne, dandruff, and seborrhea, demonstrated by some clinical trials. This trial conducted to determine whether the herbal prebiotic Triphala is effective in reducing scalp sebum secretion in patients with scalp seborrhea.

METHODS

In this 8 week patient and outcome assessor-blinded, placebo-controlled trial participants with scalp seborrhea aged 14-50 years were randomized to Triphala or placebo groups. 1 g of Triphala (standardized as 91.82 ± 0.5 mg gallic acid) or placebo (wheat flour) were administered BID. Scalp sebum levels were detected objectively using Sebumeter^® sm 815, and treatment satisfaction was measured using a score between 0 and 100. [Registration no. IRCT2014070218332N1].

RESULTS

Eighty patients completed the study (40 in Triphala group and 40 in placebo group). Participants in the Triphala group experienced 25.34 scores (95% CI, 0.39-50.29: p = .047) more improvement in scalp sebum levels compared with the placebo group. The mean percentage of patients' satisfaction was 37.91 (24.88) in the Triphala group and 17.89 (25.80) in the placebo group (p = .001).

CONCLUSION

Herbal prebiotic Triphala significantly reduced scalp sebum scores compared to placebo.

Skin microbiota as a therapeutic target for psoriasis treatment: Trends and perspectives

Psoriasis is a chronic, immune-mediated disease that has a major negative impact on a patient's quality of life. Although several literature reviews indicate that skin microbiota may play an important role in the development and regulation of the immune and inflammatory response of psoriasis, few clinical studies are demonstrating the benefits of using pre-, pro- and synbiotics as a therapeutic alternative at the management of the disease. In this review, we showed the use of probiotic microorganisms that may contribute to skin homeostasis and compiled the clinical trials that demonstrate the effect of therapy with probiotics on patients with psoriasis, an important area for scientific exploration in dermatology and being the first review article to compile this information.

Exploring the wound healing, anti-inflammatory, anti-pathogenic and proteomic effects of lactic acid bacteria on keratinocytes

The topical application of lactic acid bacteria (LAB) is recognized as a useful approach to improve skin health. This work aims to characterize by a multidisciplinary approach, the wound healing, anti-inflammatory, anti-pathogens and proteomic effects of six LAB lysates, belonging to the genus Lactobacillus. Our results demonstrated that the lysates of tested LAB stimulated the proliferation of keratinocytes, and that L. plantarum SGL 07 and L. salivarius SGL 19 accelerated the re-epithelization by inducing keratinocyte migration. The bacterial lysates also reduced the secretion of specific pro-inflammatory mediators from keratinocytes. Furthermore, viable L. salivarius SGL 19 and L. fermentum SGL 10 had anti-pathogenic effects against S. aureus and S. pyogenes, while L. brevis SGL 12 and L. paracasei SGL 04 inhibited S. aureus and S. pyogenes, respectively. The tested lactobacilli lysates also induced specific proteome modulation of the exposed keratinocytes, involving dysregulation of proteins (such as interleukin enhancer-binding factor 2 and ATP-dependent RNA helicase) and pathways (such as cytokine, NF-kB, Hedgehog, and RUNX signaling) associated with their specific wound healing and anti-inflammatory effects. This study indicates the different potential of selected lactobacilli, suggesting that they may be successfully used in the future together with conventional therapies to bring relief from skin disorders.