An individual’s microbiome is increasingly recognized to be a major determinant of their immune system function. Consequently, there is great interest in manipulating one’s microbiota to influence the immune system to promote health and prevent disease. Accordingly, this meeting, entitled Immunoregulatory Microbiota, will focus on understanding molecular mechanisms by which microbiota impact innate and adaptive immunity and how this information can be harnessed to develop novel medical therapies. These themes are highly complementary with the Early Life and Immune Tolerance meeting being held jointly with this symposium. Presentations will cover a range of ubiquitous and sporadically present microbiota capable of impacting the immune system in an array of host organs.  The symposia will bring together microbiologists, immunologists, physician-scientists, and developers of cutting-edge technologies for study of microbiota-immune cell interactions. The unique angle of this assemblage of experts will be their focus on the immune system as the nexus via which microbiota impact health and disease.  We expect the symposia will advance basic understanding of microbiota-immune cell interactions and efforts to deploy them to improve clinical outcomes.