The Skin Microbiome: A Focus on Pathogens and Their Association with Skin Disease

Microbes are present in every environmental niche and live in close association with humans and each other. Members of these communities include bacteria, archaea, viruses, fungi, and protists. In the environment, microbes perform various roles and are essential in agriculture and food production. In humans and animals, microbes provide protection against foreign invaders, educate and stimulate the immune response, produce antimicrobials, aid in digestion, and produce vitamins, among a host of other functions. In the last decade, researchers have actively investigated the impact of microbes and their gene products in human health and disease. This field of research is defined as the human microbiome, which is the totality of the microbes and their genes in and on the human body. To better understand the impact of microbes on health and disease, multiple body sites have been investigated, including skin, lungs, the nasal passage, the oral cavity, and the gastrointestinal and urogenital tracts. The results of these studies have revealed that each body site is home to a unique microbial community. Shifts in microbial communities can result from multiple factors, including environment, genetic variation, lifestyle and hygienic factors, and the immune system, and have been associated with many diseases.