Localization of Gammaproteobacteria and evidence of Proteobacteria migration into the crypts within the distal colon of mice inoculated with C. rodentium (CR+) and rectally administered PBS (BU0) or butyrate at a concentration of 140 mM (BU140). Localization of Gammaproteobacteria and evidence of Proteobacteria migration into the crypts within the distal colon of mice inoculated with C. rodentium (CR+) and rectally administered PBS (BU0) or butyrate at a concentration of 140 mM (BU140). (A) Abundance of Enterobacteriaceae and Gammaproteobacteria associated with the mucosa on day 14 postinoculation (p.i.) in mice inoculated with PBS and C. rodentium (B) Abundance of Enterobacteriaceae and Gammaproteobacteria associated with mucosa on day 21 p.i. in mice inoculated with PBS and C. rodentium. Vertical lines associated with histogram bars represent standard errors of the means (n = 4). **, P ≤ 0.010 (for treatments linked by the horizontal lines). (C to F) Fluorescence micrographs of distal colonic tissue hybridized with a Gammaproteobacteria probe (red). (C) CR+ BU− at day 14 p.i. (bar, 200 µm). (D) CR+ BU+ at day 14 p.i. (bar, 200 µm). (E) CR+ BU− at day 21 p.i. (bar, 100 µm). (F) CR+ BU+ at day 21 p.i. (bar, 200 µm). The arrows indicate subluminal Proteobacteria. Janelle A. Jiminez et al. mSphere 2017; doi:10.1128/mSphere.00243-17