FIGURE 4.

Dysbiosis induces upregulation of Duox2 and enhances the epithelial release of H₂O₂. Germ-free mice were colonized with the mucosa-associated microbiota of WT or dysbiotic (villin-TLR4) mice and their epithelial responses were analyzed after a 3-week engraftment. (A) Engraftment experiments diagram. (B) Representative micrographs showing no signs of inflammation and no major morphological differences between WT- and dysbiotic-microbiota recipient mice. Inset scale bar = 50 μm; micrograph scale bar = 1 mm. (C) MPO activity in colon from engrafted mice. (D) NADPH oxidase expression in IECs isolated from engrafted mice. Duox2-dysbiotic vs. Duox2-WT, ^∗P < 0.05 as determined by two-tailed Student’s t-test (n = 3 mice). (E) H₂O₂ production rate in IECs isolated from engrafted mice. Dysbiotic vs. WT, ^∗∗P < 0.01 as determined by two-tailed Student’s t-test (n = 3 mice).