Fig. 4.

Ileal histopathology in recolonized gnotobiotic mice following ileitis induction. Gnotobiotic mice generated by quintuple antibiotic treatment were perorally recolonized with E. coli Nissle 1917 (EcN), E. coli K12 (EcK12) or a commensal E. coli (EcCo) strain as described in methods. Four days thereafter, E. coli recolonized mice (gray circles) were perorally infected with 100 cysts of Toxoplasma gondii in order to induce acute ileitis. With conventional microbiota recolonized (SPF; black circles) and gnotobiotic (GB; white circles) animals served as positive and negative controls, respectively. Histopathological scores of the terminal ileum were assessed at day 7 following ileitis induction. Numbers of analyzed animals are given in parentheses. Mean values and significance levels as determined by the Student’s t-test are indicated. Data were pooled from three independent experiments.