Microbiome of the skin: The good and the bad Chronic wounds are a significant burden to patients and health systems; Manuela Martins-Green from the University of California tells us how her research in understanding the dynamics of wound healing could aid new approaches to wound care. The skin is the largest organ in the human body. It is the barrier that protects the organs from the environment, functioning as an interface between the environment and the inside of the body. Residing on the skin is a complex and diverse community of microbes called the microbiome. Trillions of microbes across bacterial and fungal families use a wide range of aerobic and anaerobic metabolic pathways to survive. Considerable effort is being put into studying the role of the microbiome in skin infections, disorders, and disease. Host- microbiome interactions are particularly important during wound healing because changes in microenvironmental conditions in the tissue can change commensal bacteria into pathogens that infect the wound chronically, including forming biofilm.