Acute loss of intestinal immune cells, specifically in the Peyer’s patches (PP), has been described after stroke.18,19,21,43 In agreement, we saw reduced PP cellularity, driven by a loss of CD4 T cells and B cells at 5 days post-stroke (Figure 4(f)–(j)) and the proportion of intraepithelial and lamina propria lymphocytes remained unchanged (Figure S5(c)–(g)). Here, CD4 is linked to stroke disorder.