Fig. 4

Neonatal antibiotic treatment increases susceptibility to DSS colitis in Nod2^−/− mice 5 weeks later. a Experimental timeline. Mice were given antibiotic-supplemented water or untreated water following birth until weaning on day 21. Colitis was induced on day 56 (when mice were 8 weeks of age) by providing 3.5% DSS water for 5 days. Tissues were analyzed on day 8 from DSS induction. Untreated Nod2^−/− mice that did not receive DSS served as negative controls (green). b Percent of initial weight over time. c Fecal lipocalin-2 concentration was measured by ELISA and normalized to stool weight. d Colon length, measured on day 8. e Colonic pathology score on day 8. f Representative photographs at ×100 magnification of H&E stained sections of the colon on day 8. Data are presented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001; by two-way ANOVA and post hoc Holm–Šídák test (b, c) and Mann–Whitney U test (d, e). (n = 9–19 mice per genotype, per treatment from five untreated litters and six antibiotic-treated litters)