Our skin is home to billions of microorganisms, the vast majority of which are bacteria. Much like the microbiome in our gut, these microbes play a crucial part in keeping us healthy. They are part of a finely balanced ecosystem of friendly or ‘commensal’ bacteria, which protect our skin by creating an inhospitable environment for would-be invaders, bolstering the physical integrity of the skin, and training the immune system to distinguish commensal inhabitants from pathogens. A number of skin conditions are now understood to be influenced by a breakdown of this microbial ecosystem. Researchers are working out whether restoring the balance can treat these conditions. Understanding the ecology of this rich community is likely to be an important part of both dermatology and the study of the microbiome. Read more in https://www.nature.com/collections/sk…