Candida gut commensalism and inflammatory disease

The mammalian intestine harbors a collection of microbes ranging from viruses, archaea, protozoa, helminths, bacteria to fungi. This trans-kingdom community, the microbiota, has been demonstrated to modulate host immunity in health and disease. While bacterial components in this community have been extensively studied in the last two decades, the impact and composition of the fungal community in the gut, the mycobiome, have been recently unraveled. Multiple inflammatory diseases have been shown to link to change of gut mycobiome composition, predominantly the abundance of Candida species in the feces. While Candida species as a major colonizer in immunocompetent human beings are mostly supposed not harmful, they can cause life-threatening systemic infection under immunocompromised situation. Here we review the recent advances about the impact of Candida gut colonization on host immunity and development of inflammatory diseases in the absence of infections. We also discuss potential gaps in understanding the role of Candida species in inflammatory disease and the future perspective.