The skin is home to a rich ecosystem of bacteria, fungus, viruses, bacteriophages, and archaeal groups. The use of culture-independent techniques has revolutionised the characterization of the skin microbiome, revealing hitherto unappreciated phylogenetic and functional granularity of skin-associated microorganisms in both health and disease states. The site-specific changes in bacterial phyla composition of healthy skin are driven by the physiology of a given skin niche. Changes in the skin microbiota have been repeatedly linked to atopic dermatitis. Staphylococcus aureus overgrowth, along with a decrease in Staphylococcus epidermidis, is a typical characteristic linked with atopic dermatitis that is not limited to eczematous lesions. Changes in fungal species are increasingly being described as well. Skin health is linked to changes in the composition and metabolic activity of the gut bacteria.

We are only now beginning to understand the delicate and nuanced relationships that exist between microorganisms and skin health. Several researches are now being conducted to investigate the therapeutic potential of the skin or gut microbiome in the prevention and treatment of skin inflammation.