The intestinal microbiota is a complex community of bacteria, archaea, viruses, protists and fungi 1,2 . While the composition of bacterial constituents has been linked to immune homeostasis and to infectious susceptibility [3][4][5][6][7] , the role of non-bacterial constituents and of cross-kingdom microbial interactions in these processes is poorly understood 2,8 . Fungi represent a major cause of infectious morbidity and mortality in immune-compromised individuals, though the relationship of intestinal fungi (i.e., the mycobiota) with fungal bloodstream infections (BSI) remains undefined 9 .Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use: