Host-microbe interactions: commensal fungi in the gut

Fungi are ubiquitous microbes that are common in diverse environments including as commensal organisms on the human body. In addition to its obvious role as a digestive organ, the intestines have been further appreciated as important for the development, maintenance, and instruction of the immune system. The gut harbors many types of microorganisms including bacteria, archaea, fungi, and viruses, and many studies over the past couple of decades have documented an important role for intestinal bacteria in immunological function. Recent studies are now suggesting that intestinal fungi (the gut 'mycobiome') may similarly play important roles in host immunity and inflammation. This review will discuss recent studies that will influence our growing understanding of the role(s) of intestinal fungi in health and disease.