Five days after AOM administration (at 12 mg/kg), Nod2+/+ (n = 4), Nod2–/– (n = 3), antibiotic-treated (Atb-treated) WT (n = 4), and Atb-treated Nod2–/– (n = 3) mice were subjected to 2% DSS for 7 days followed by 9-day access to regular drinking water. (A) Changes in body weight were monitored daily. (B) Colonic-associated Bacteroides load was determined by specific q-PCR analysis at day 16. (C–E) Ly6G, IA/IE, CD11c, and CD11b staining of the lamina propria cell population in Nod2–/– mice treated or not with antibiotics as indicated was quantified by FACS analysis. (F) Colon weight/length ratio quantification on Nod2+/+ (n = 10), Nod2–/– (n = 9), antibiotic-treated Nod2+/+ (n = 10) and antibiotic-treated Nod2–/– (n = 10) mice was performed at day 58. *P < 0.05; **P < 0.01; ***P < 0.001.