Figure 5. Induction of A. parvulum-associated colitis requires the gut microbiota and hydrogen sulfide.

(a) Representative histological Swiss-rolled sections of the colon of Il10^−/− mice associated (+) or not associated (−) with A. parvulum, treated (+) or not treated (−) with bismuth and kept under specific pathogen free (SPF) conditions for 14 weeks. (b) Representative murine endoscopies of SPF Il10^−/− mice associated (+) or not-associated (−) with A. parvulum, treated (+) or not-treated (−) with bismuth. (c) Blinded inflammation scores (n=7 to 8 per group) for Il10^−/− mice under SPF conditions; crosses indicate the mean while horizontal lines indicate the median; two-tailed Mann–Whitney test was used for statistical comparison; *P<0.05, ***P<0.001.