Correlations among changed gut microbiota composition, microbiota function, and altered colitis-related parameters. (A) Microbiota function predicted by PICRUSt2 (control versus DSS group, DSS versus co-CB+DSS group, DSS versus co-EV+DSS group). (B) Shigella effector lpac (lpaB) expression upon each group. (C) Spearman correlation between changed gut microbiota composition, microbiota function, and altered colitis-related parameters (cor > 0.8, P > 0.01). *, P ≤ 0.05; **, P ≤ 0.01 versus the control group, #, P ≤ 0.05; ##, P ≤ 0.01 versus the DSS group.