Chow diet induces Granzyme B expression in intestinal T cells. (A and B) Flow cytometry analysis of Granzyme B expression within IE T cell subsets from 8-wk-old SPF or GF mice fed AA or standard chow diet. Mean ± SD from two to three independent experiments with 7–11 mice per condition. Unpaired t tests (A) or two-way ANOVA P values beneath each plot, and P < 0.05 from Holm-Šidák multiple comparison test between diets within each colonization displayed on each plot (B). (C) Schematic of weaning and diet switch experiments. (D) Flow cytometry analysis of 3-, 8-, and 12-wk-old SPF mice fed chow or AA diets according to schematic C. Mean ± SEM from two to five independent experiments with 5–18 mice per condition. One-way ANOVA comparing conditions in 12-wk-old mice displaying P < 0.05 from Tukey’s multiple comparison test to the right of each plot. Unpaired t tests comparing consecutive timepoints between conditions with Holm-Šidák correction for multiple comparisons displayed on plot. (E) Flow cytometry of Granzyme B expression within IE T cell subsets from 12-wk-old SPF mice fed chow or AA diets according to schematic C. Mean ± SD from two independent experiments with five to seven mice per condition. Two-way ANOVA displaying P < 0.05 from Dunnett’s multiple comparison test comparing each group against chow only. (A–E) *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.