It is also home to communities of microbes that interact with the skin barrier and the immune system. This shift could change what skincare products are designed to do, how companies test them, and which claims regulators permit. A network of immune cells also detects potentially harmful substances, clears damaged cells, and helps prevent immune reactions from continuing for too long. Researchers are therefore studying whether skincare products might reduce harmful inflammation as well as protect against sun-related skin aging. Microbes can interact with immune cells and help defend against pathogens.