Redefining The Skin Barrier: A Microbiome-Integrated Multilayered Defense Model

This review redefines the skin barrier as a dynamic ecosystem composed of interconnected physical, chemical, immune, and microbial components. It emphasizes the crucial role of the skin microbiome in maintaining barrier function through niche competition, immune modulation, and reinforcement of physical and chemical defenses. Key findings include the production of antimicrobial peptides and organic acids by skin microbiota, which protect against pathogens and maintain an acidic environment. The review highlights the potential of microbiome-targeting therapies, such as live biotherapeutics and bacteriocin-based antimicrobials, and stresses the importance of precision formulation due to strain-specific effects. Understanding these interactions is vital for managing skin disorders and restoring barrier integrity, suggesting that the skin functions as an integrated superorganism.