IL17A and ischemic stroke: Antibiotic-induced alterations in the gut microbiota reduced brain injury after ischemic stroke.Dysbiosis following ischemic stroke changed intestinal immune homeostasis, leading to an increase in regulatory T(Treg) cells and a reduction in IL-17+ γδ T cells through altered dendritic cell activity. Moreover, dysbiosis blocked the migration of effector T cells from the gut to the leptomeninges.