Microbiome Modulation as a Therapeutic Approach in Chronic Skin Diseases

Gut microbiota and skin pathologies: Mechanism of the gut-skin axis in atopic dermatitis and psoriasis

Atopic dermatitis (AD) and psoriasis are chronic skin diseases with a global impact, posing significant challenges to public health systems and severely affecting patients' quality of life. This review delves into the key role of the gut microbiota in these diseases, emphasizing the importance of the gut-skin axis in inflammatory mediators and immune regulation and revealing a complex bidirectional communication system. We comprehensively assessed the pathogenesis, clinical manifestations, and treatment strategies for AD and psoriasis, with a particular focus on how the gut microbiota and their metabolites influence disease progression via the gut-skin axis. In addition, personalized treatment plans based on individual patient microbiome characteristics have been proposed, offering new perspectives for future treatment approaches. We call for enhanced interdisciplinary cooperation to further explore the interactions between gut microbiota and skin diseases and to assess the potential of drugs and natural products in modulating the gut-skin axis, aiming to advance the treatment of skin diseases.

Identification of psoriasis-associated immune marker G3BP2 through single-cell RNA sequencing and meta analysis

Psoriasis is a chronic skin disease with an increasing prevalence each year. However, the mechanisms underlying its onset and progression remain unclear, and effective therapeutic targets are lacking. Therefore, we employs an innovative approach by combining single-cell RNA sequencing (scRNA-seq) with meta-analysis. This not only elucidates the potential mechanisms of psoriasis at the cellular level but also identifies immunoregulatory marker genes that play a statistically significant role in driving psoriasis progression through comprehensive analysis of multiple datasets. Skin tissue samples from 12 psoriasis patients underwent scRNA-seq, followed by quality control, filtering, PCA dimensionality reduction, and tSNE clustering analysis to identify T cell subtypes and differentially expressed genes (DEGs) in psoriatic skin tissue. Next, three psoriasis datasets were standardised and merged to identify differentially expressed genes (DEGs). Subsequently, weighted gene co-expression network analysis (WGCNA) was applied for clustering analysis of gene co-expression network modules and to assess the correlation between these modules and DEGs. Least absolute shrinkage and selection operator (LASSO) regression and receiver operating characteristic (ROC) curve analyses were conducted to select disease-specific genes and evaluate their diagnostic value. Single-cell data revealed nine cell types in psoriatic skin tissue, with seven T cell subtypes identified. Intersection analysis identified ADAM8 and G3BP2 as key genes. Through the integration of scRNA-seq and Meta analysis, we identified the immunoregulatory marker gene G3BP2, which is associated with the onset and progression of psoriasis and holds clinical significance. G3BP2 is speculated to promote the development of psoriasis by increasing the proportion of CD8+ T cells.

Study of gut microbiome alterations in plaque psoriasis patients compared to healthy individuals

Introduction

Many studies have shown significant alterations in the gut microbiome of patients with psoriasis compared to healthy controls.

Aim

The primary objective of the current research was to explore the impact of gut microbiome composition on the progression and severity of plaque psoriasis.

Material and methods

A total of 20 patients with moderate-to-severe psoriasis and 20 healthy individuals were recruited and provided a stool sample to assess the gut microbiome. After the samples were prepared according to the NGS library preparation workflow, they were sequenced using the Illumina platform and the report was generated that underwent statistical analysis.

Results

The microbiome profiles of psoriasis patients exhibited significant differences compared to healthy controls as evidenced by the statistical analysis of various bacterial genera, with the median abundance significantly lower in psoriasis patients compared to healthy controls (p = 0.033). The analysis of the Firmicutes-to-Bacteroidetes ratio, a commonly evaluated marker of dysbiosis, did not reach statistical significance (p = 0.239). However, there was a noticeable trend towards a higher median ratio in psoriasis patients compared to healthy controls. The ratio did not show significant associations with PASI or BSA but trends towards significance with DLQI (B = -12.11, p = 0.095).

Conclusions

Overall, the above findings underscore the importance of the gut microbiome in psoriasis and suggest that modulation of specific bacterial genera, especially that with significant differences, could be a potential strategy for therapeutic intervention. Targeting these depleted genera through microbiome-based interventions, such as probiotic supplementation or faecal microbiota transplantation, could potentially help to restore gut homeostasis and alleviate the inflammatory burden in psoriasis.

The Role of Probiotics in Skin Care: Advances, Challenges, and Future Needs

The skin, being the largest organ in the human body, plays a pivotal role in safeguarding the body against invasive pathogens. Therefore, it is essential to reinforce and protect this vital organ. Current research supports the impact of probiotics on skin health and their ability to alleviate various skin disorders. However, the effectiveness and probable side effects of probiotics in skin care remain a subject of debate, necessitating further investigation and analysis. Hence, this study aims to highlight existing gaps and future needs in the current research on probiotics in skin care and pave the way for future investigations. Therefore, we scrutinized the effects of oral (fermented foods and dietary supplements) and non-oral/topical probiotics on skin care, and the mechanism of probiotics that affect skin health. The results of most studies showed that fermented foods containing probiotics, particularly dairy products, positively impact skin health. The research results regarding the efficacy of probiotic supplements and live strains in treating skin disorders show promising potential. However, safety evaluations are crucial, to identify any potential adverse effects. While research has identified numerous potential mechanisms by which probiotics may influence skin health, a complete understanding of their precise mode of action remains elusive. However, it seems that probiotics can exert their positive effects through the gut-skin and gut-skin-brain axis on the human body. Therefore, following the identification of safe probiotics, additional studies should be carried out to establish optimal dosages, potential side effects, suitable regulatory guidelines, and validation methods.

A non-inferiority clinical trial comparing probiotics and oral corticosteroids for the management of acute exacerbation of atopic dermatitis patients

A prospective controlled pilot study on the feasibility of utilization of a probiotic mixture for management of acute exacerbation of atopic dermatitis (AD). Patients were allocated to either standard of care (SOC) therapy with tapering dose of steroids or a probiotic mixture over 3 weeks. After the 3-week intervention, patients on steroids achieved significantly higher clinical response rates and significantly deeper response as measured by the change in SCORAD score. No gut microbiome changes could be appreciated in either group after the treatment period. We could conclude that probiotics cannot replace SOC therapy for the management of acute exacerbation of AD.

Bacteriocins: potentials and prospects in health and agrifood systems

Bacteriocins are highly diverse, abundant, and heterogeneous antimicrobial peptides that are ribosomally synthesized by bacteria and archaea. Since their discovery about a century ago, there has been a growing interest in bacteriocin research and applications. This is mainly due to their high antimicrobial properties, narrow or broad spectrum of activity, specificity, low cytotoxicity, and stability. Though initially used to improve food quality and safety, bacteriocins are now globally exploited for innovative applications in human, animal, and food systems as sustainable alternatives to antibiotics. Bacteriocins have the potential to beneficially modulate microbiota, providing viable microbiome-based solutions for the treatment, management, and non-invasive bio-diagnosis of infectious and non-infectious diseases. The use of bacteriocins holds great promise in the modulation of food microbiomes, antimicrobial food packaging, bio-sanitizers and antibiofilm, pre/post-harvest biocontrol, functional food, growth promotion, and sustainable aquaculture. This can undoubtedly improve food security, safety, and quality globally. This review highlights the current trends in bacteriocin research, especially the increasing research outputs and funding, which we believe may proportionate the soaring global interest in bacteriocins. The use of cutting-edge technologies, such as bioengineering, can further enhance the exploitation of bacteriocins for innovative applications in human, animal, and food systems.

Microbiome: Role in Inflammatory Skin Diseases

As the body's largest organ, the skin harbors a highly diverse microbiota, playing a crucial role in resisting foreign pathogens, nurturing the immune system, and metabolizing natural products. The dysregulation of human skin microbiota is implicated in immune dysregulation and inflammatory responses. This review delineates the microbial alterations and immune dysregulation features in common Inflammatory Skin Diseases (ISDs) such as psoriasis, rosacea, atopic dermatitis(AD), seborrheic dermatitis(SD), diaper dermatitis(DD), and Malassezia folliculitis(MF).The skin microbiota, a complex and evolving community, undergoes changes in composition and function that can compromise the skin microbial barrier. These alterations induce water loss and abnormal lipid metabolism, contributing to the onset of ISDs. Additionally, microorganisms release toxins, like Staphylococcus aureus secreted α toxins and proteases, which may dissolve the stratum corneum, impairing skin barrier function and allowing entry into the bloodstream. Microbes entering the bloodstream activate molecular signals, leading to immune disorders and subsequent skin inflammatory responses. For instance, Malassezia stimulates dendritic cells(DCs) to release IL-12 and IL-23, differentiating into a Th17 cell population and producing proinflammatory mediators such as IL-17, IL-22, TNF-α, and IFN-α.This review offers new insights into the role of the human skin microbiota in ISDs, paving the way for future skin microbiome-specific targeted therapies.

Modulating the skin mycobiome-bacteriome and treating seborrheic dermatitis with a probiotic-enriched oily suspension

Seborrheic dermatitis (SD) affects 2-5% of the global population, with imbalances in the skin microbiome implicated in its development. This study assessed the impact of an oily suspension containing Lactobacillus crispatus P17631 and Lacticaseibacillus paracasei I1688 (termed EUTOPLAC) on SD symptoms and the skin mycobiome-bacteriome modulation. 25 SD patients were treated with EUTOPLAC for a week. Symptom severity and skin mycobiome-bacteriome changes were measured at the start of the treatment (T0), after seven days (T8), and three weeks post-treatment (T28). Results indicated symptom improvement post-EUTOPLAC, with notable reductions in the Malassezia genus. Concurrently, bacterial shifts were observed, including a decrease in Staphylococcus and an increase in Lactobacillus and Lacticaseibacillus. Network analysis highlighted post-EUTOPLAC instability in fungal and bacterial interactions, with increased negative correlations between Malassezia and Lactobacillus and Lacticaseibacillus genera. The study suggests EUTOPLAC's potential as a targeted SD treatment, reducing symptoms and modulating the mycobiome-bacteriome composition.

The efficacy of probiotic-derived lotion from Lactobacillus paracasei MSMC 39-1 in mild to moderate acne vulgaris, randomized controlled trial

BACKGROUND

Probiotics provide benefits for reducing acne. Previous studies showed an anti-inflammatory effect of Lactobacillus paracasei. However, the clinical evidence of topical probiotic lotion and acne treatment is still lacking.

OBJECTIVE

To evaluate the efficacy and safety of probiotic-derived lotion compared to 2.5 % benzoyl peroxide in the treatment of mild to moderate acne vulgaris.

METHODS

Topical probiotic-derived lotion was formulated from cell-free supernatant of L. paracasei MSMC 39-1. In vivo study showed the ability of the supernatant to inhibit both antibiotic-resistance and susceptibility strains of C. acnes and inhibit tumor necrosis factor-α. The patients with mild to moderate acne vulgaris on the face were randomized to receive topical probiotic-derived lotion or 2.5 % benzoyl peroxide. Acne lesion counts, erythema index, and side effects were assessed after 2 and 4 weeks of treatment.

RESULTS

One hundred and four acne vulgaris patients were enrolled. After four weeks of treatment, the inflammatory acne lesion counts and erythema index significantly decreased compared to baseline in both the probiotic lotion group and 2.5 % benzoyl peroxide group (p < 0.001 in both groups) without statistically significant difference between the two groups (p > 0.05). However, the comedones were not affected in both groups. Four patients (7.69%) treated with probiotic-derived lotion and 14 patients (26.92%) treated with 2.5% benzoyl peroxide reported treatment-associated side effects.

CONCLUSION

Probiotic-derived lotion is safe and effective for treating mild to moderate acne vulgaris, a comparable outcome with 2.5% benzoyl peroxide. It could be an alternative treatment of acne with more minor side effects.

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.