Fig. 1.

Obesity enhances colonic inflammation and CAC tumour burden in C57BL/6 mice. a, b qPCR analysis of indicated gene expression in distal colons derived from 8-week-old non-colitic NCD (n = 5) and HFD-fed (n = 5) C57BL/6 mice; following results are presented relative to non-colitic NCD. c Scheme of the 1.5% AOM/DSS protocol of mice fed a NCD or a HFD from weaning (3 weeks of age) until the end of the experiment with 17 weeks of age. 8-week-old mice were injected with 10 mg/kg AOM i.p. at day 1 of the 1.5% AOM/DSS protocol. From day 5 on, mice received 1.5% DSS in the drinking water for 5 days. Mice were either killed with 8 weeks of age at day 0 (non-colitic), 10 weeks of age at day 13 for analysis of colitic conditions (colitic) or with 17 weeks of age at day 62 (non-tumour and tumour) for analysis of tumourigenesis. d, e qPCR analysis of indicated gene expression in distal colons of 10-week-old NCD (n = 5) and HFD-fed (n = 5) colitic C57BL/6 mice; results are presented relative to non-colitic NCD. f Normalised albumin concentration in faeces of NCD (n = 10) and HFD-fed (n = 10) C57BL/6 mice under non-colitic (day 0) and colitic (day 13) conditions. g Representative endoscopic pictures of 13-week-old NCD and HFD-fed C57BL/6 mice of the 1.5% AOM/DSS protocol. h Tumour number of 17-week-old NCD (n = 18) and HFD-fed (n = 13) C57BL/6 mice counted at day 62 of the 1.5% AOM/DSS protocol. AOM, azoxymethane; DSS, dextran sodium sulphate, NCD, normal chow diet; HFD, high-fat diet; CAC, colitis-associated colorectal cancer. centre line: median; box limits: 1st and 3rd quartiles; whisker: maximum to minimum, *p ≤ 0.05, **p ≤ 0.01 and ***p ≤ 0.001 two-tailed unpaired Student’s t-test a, b, h or two-way ANOVA followed by Fisher LSD d–f