Skin microbiome

The totality of microorganisms that colonize the skin (microbiota), along with their structural components, metabolites, and signaling molecules. The skin microbiome is influenced by different body locations, gender, age, skincare products, and environmental conditions. The microbiota includes bacteria, fungi, single-celled and multicellular organisms, and viruses. These include, in particular, Staphylococcus epidermidis, Staphylococcus aureus, Corynebacteria, Propionibacteria, Proteobacteria—including Pseudomonas and Bacteroides—as well as fungi such as Malassezia species, viruses, and bacteriophages. 

Microorganisms can modulate both innate and adaptive immune responses

The skin microbiota also shapes the skin’s immune response and promotes the integrity of the skin barrier and tissue integrity. Approximately 1,000 bacterial species colonize the human skin; they are essential for skin health and play an important role in conditions such asatopic dermatitis, psoriasis, diabetic foot syndrome, hidradenitis suppurativa, rosacea, seborrheic dermatitis, acne, and skin malignancies. Advances in molecular biology are providing a deeper understanding of the skin microbiome and its role in skin diseases, thereby paving the way for promicrobial therapeutic approaches; see also “Microbiome, ” “Microbiomics, ” “Probiotics,” “Prebiotics,” and “Symbiotics.”

For example, patients with atopic dermatitis exhibit reduced diversity in the skin microbiome, which correlates with the severity of skin lesions and increased colonization by Staphylococcus aureus.

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