Our skin is the largest organ in the body and serves as the first line of defense against the outside world. But beyond being a physical barrier, the skin is home to a complex ecosystem known as the skin microbiome.

The skin microbiome is made up of trillions of microorganisms, including bacteria, fungi, and other microbes that naturally live on the surface of the skin. Scientists estimate that the skin microbiome may include over 1,000 different species of bacteria and dozens of types of fungi.

These microorganisms are not harmful—in fact, many of them are essential for healthy skin.

Understanding how the skin microbiome works can help explain why gentle skincare, balanced routines, and barrier-supporting ingredients are so important for maintaining comfortable, resilient skin.