The skin microbiome: from historical ecology to therapeutic frontiers^☆

Background:  Human skin, the body’s largest organ, hosts a diverse ecosystem of bacteria, fungi, viruses, and mites collectively known as the skin microbiome. This microbiome supports cutaneous homeostasis through barrier defense, immune education, and metabolic functions. Objective: To narratively review the historical evolution of skin microbiome research, synthe-size current knowledge on its composition, biogeography, and functional roles in health and disease, and highlight emerging microbiome-based therapeutic strategies in dermatology.

Methods:  This review integrates seminal historical works with contemporary evidence from culture-independent sequencing and multi-omic investigations of the skin microbiome, identi-fied through a selective search of recent dermatology and microbiome literature.

Results:  Modern molecular and multi-omic approaches have revealed microbial diversity across sebaceous, moist, and dry skin niches and clarified key functions of the skin microbiome, includ-ing colonization resistance, immune modulation, metabolite production, and participation in the gut-skin axis. Dysbiosis of these communities is linked to inflammatory conditions such as atopic dermatitis, acne vulgaris, psoriasis, and chronic wounds. A growing body of work supports microbiome-targeted interventions, including probiotics, prebiotics, postbiotics, and microbiome engineering, as promising personalized strategies. Study limitations: As a narrative review, this work may be subject to selection bias and does not provide a quantitative synthesis of all available studies on the skin microbiome.

Conclusions:  By integrating historical context with mechanistic insights from modern micro-biome research, this review underscores the skin microbiome as a central ecological determinant of cutaneous health and disease and provides a framework for translating micro-biome science into clinical applications and precision dermatology.

KEYWORDS
Atopic dermatitis; Gastrointestinal microbiome; Infectious skin diseases; Microbial dysbiosis; Skin microbiome; Therapeutics