The skin microbiome is the collection of the trillions of organisms that live on the skin. As I’ve noted, there’s a lot we don’t know about it, but we do know that it communicates with our immune system, manages inflammation, protects against environmental stressors, and produces vital nutrients for the skin (called postbiotics). We also know that the organisms that make up the microbiome are dynamic and ever-changing. Lots of things can influence which species live on and dominate your skin, such as your age, hormones, your environment, and more.