Gut Fungal Microbiota: The Yin and Yang of Inflammatory Bowel Disease

The prevalence of inflammatory bowel diseases (IBD) has been steadily increasing since 1960. They are widespread throughout Europe, North America, China, and Japan and are emerging as a global disease. The equilibrium among epithelial cells, the immune system, and the related microbiota seems to be paramount in ensuring the absence of these IBD. The role of bacteria in the setting of the gut microbiota has been thoroughly documented, but the role of fungi, which are less abundant, needs to be investigated. Our understanding of the fungal microbiota composition and its impact on IBD has greatly increased in the past 8 years. In this review, we compiled data obtained for the composition of fungal gut microbiota. Special attention was paid to the various effects of this microbial community on the IBD, i.e., the mechanisms and immune pathways involved in these interactions.