Population genomics of Saccharomyces cerevisiae human isolates: passengers, colonizers, invaders.

The quest for the ecological niches of Saccharomyces cerevisiae ranged from wineries to oaks and more recently to the gut of Crabro Wasps. Here we propose the role of the human gut in shaping S. cerevisiae evolution, presenting the genetic structure of a previously unknown population of yeasts, associated with Crohns disease, providing evidence for clonal expansion within humans gut. To understand the role of immune function in the human-yeast interaction we classified strains according to their immunomodulatory properties, discovering a set of genetically homogeneous isolates, capable of inducing anti-inflammatory signals via regulatory T cells proliferation, and on the contrary, a positive