Fig. 1: HFD-induced obese mice have protracted C. difficile infection (CDI).

Experimental plan: RD-fed and HFD-fed mice were pre-treated with antibiotics for 5 days in drinking water and challenged with 1 × 103 C. difficile (VPI 10463) spores by oro-gastric gavage two days after cessation of antibiotics. Animals were monitored until day 15, scored for clinical symptoms, and sacrificed at day 3 and 10 to collect samples (a). Disease severity was evaluated based on diarrhea score (b), duration of diarrhea (c), and percentage change in body weight after CDI (compared to day 0 weight) (d). Extent of tissue damage was evaluated based on changes in colon length (e), and histological findings (f–h). Representative H&E images of cecal sections (f) and total histology score (g) from day 3 and day 10 of CDI. Scores of individual histological parameters (inflammation, epithelial damage, and submucosal edema) on day 10 of CDI (h). Number of WBCs, neutrophils, monocytes and eosinophils in cecal tissue (i–j) on day 3 (i) and day 10 (j) of CDI. Data are means ± SEM. n = 10–21 for b–d; n = 10–18 for e, g, h; n = 6–10 for i, j; data presented in b–e and g, h pooled from 2 to 3 experiments. *p < 0.05, **p < 0.01, ***p < 0.001; repeated measures ANOVA (b, d), and two-tailed Student’s t-test (c, e, g–j).