The skin is the largest organ in the human body and is constantly exposed to a variety of environmental stressors, including pollution, UV radiation, and temperature fluctuations. To protect itself, the skin relies on a complex ecosystem of microorganisms known as the skin microbiome. In recent years, there has been a growing interest in the role of the skin microbiome in maintaining skin health, and microbiome-friendly skincare has emerged as a new trend in the beauty industry. In this book, we will explore the science behind the skin microbiome and its relationship to skin health, as well as practical tips for developing a microbiome-friendly skincare routine.