Intestinal DUOX2 expression depends on microbial colonization. Relative Duox2 (A) and Duoxa2 (B) mRNA expression in GF (n=5) and SPF (n=7) mice. Data represent geometric means±95% CI. dd, duodenum; je, jejunum; il, ileum; co, colon; re, rectum. (C) Immunoblot of DUOX2 protein. ACTB, β-actin loading control. (D, E) Relative mRNA expression of Duox1 and Nox1. Data represent geometric means±95% CI. (F) Effect of acute enteral antibiotic treatment on ileal Duox2 and Duoxa2 expression. Mice were analyzed 24 hours following oral gavage with streptomycin (20 mg; Abx); SPF, sham treated control. Bars indicate geometric means. ****, P<.0001; ***, P<.001; **, P<.01; *, P<.05.