R-Spo1 suppresses GVHD-induced bacterial translocation into the gastric mucosa. Lethally irradiated B6D2F1 mice received transplantation and were treated with R-Spo1 as in Figure 2. The stomach and duodenum were harvested on day +7. (A-B) Numbers of parietal cells identified by PAS staining (A; n = 4 per group) and pH of the gastric lumen (B; n = 10-13 per group). (C) H&E staining of stomach. Areas in the black squares were magnified and shown in the bottom of the original images. Bars represent 50 μm. (D) FISH targeting a pan-bacterial marker, EUB338 (red), with DAPI nuclear staining (blue). Bars represent 100 μm. (E) Numbers of bacterial colony derived from the content of duodenum (n = 9-10 per group). (B,E) Data from 2 experiments were combined and shown as mean ± standard error of the mean. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001. FISH, fluorescence in situ hybridization.