Abstract
BACKGROUND: Studies from animal models of autoimmunity have highlighted the potential importance of microorganisms and their metabolic products in shaping the immune system. SUMMARY: This review provides an introduction to the current state-of-the-art in microbiome research both from the perspective of "what is known" and of methodologies for its investigation. It then summarises the evidence for a role for the microbiome in the pathogenesis of Graves' disease and Graves' orbitopathy with reference to animal models and studies in human cohorts, from both published and ongoing sources. KEY MESSAGE: Microbiome research is in its infancy but has already provided novel insights into disease pathogenesis across the spectrum from cancer to mental health and autoimmunity.