Colitogenic microbiotas increase superoxide production at the intestinal epithelial barrier and are associated with altered patterns of NAD phosphate oxidase gene expression. Superoxide (O₂^–) production measured in RLU, normalized to WT mice, performed on CECs sorted from p47^phox–/– mice at IRCM or the NIH (A), WT mice cross-fostered with p47^phox–/– mice from the NIH (CF p47^phox–/–) (C), and gp91^phox–/– mice at IRCM or the NIH (E) after DSS colitis induction. The data are from 2 independent experiments for IRCM mice and 1 experiment for the NIH mice (n = 3-5 mice per group). (B,D,F) NOX isoform messenger RNA expression levels relative to WT mice in indicated mice from IRCM (n = 5-9) and the NIH (n = 3). The data are presented as medians with interquartile ranges and represent 1 to 2 independent experiments. Significance was determined using the Mann-Whitney U test (∗P < .05). (G) Relative mitochondrial ROS levels measured by MitoSOX in CECs sorted from WT, gp91^phox–/–, and p47^phox–/– mice from IRCM after DSS colitis induction (n = 3-4). RLU, relative light units.