Type 1 diabetes (T1D) is triggered by both genetic factors and environmental factors, and among the latter, the gut microbiota seems to be important. In the Journal of Experimental Medicine, Carlos and colleagues use a streptozotocin-induced model of T1D to investigate the importance of the gut microbiota. Treatment with streptozotocin leads to the translocation of bacteria to pancreatic lymph nodes and results in the production of inflammatory cytokines by macrophages and dendritic cells. Critically, the induction of these cytokines depends on expression of the intracellular bacterial sensor Nod2. Accordingly, treatment with broad-spectrum antibiotics or Nod2 deficiency in mice results in relative protection from T1D. These data reveal a mechanism by which breakdown of the gut barrier can initiate a cascade that leads to the manifestation of T1D.

J. Exp. Med. (20 June 2016) doi:10.1084/jem.20150744