IL10 and Chronic colitis: Three human bacteria, Escherichia coli LF82, Enterococcus faecalis OG1RF, and Ruminococcus gnavus ATCC29149 (EER strains) were used based on their ability to colonize GF 129 WT and 129 Il10−/− mice (Supplementary Fig. 2a, b and Supplementary Table 2), to induce chronic colitis and to activate strain-specific Th1 and Th17 mucosal immune responses in gnotobiotic Il10−/− mice20,21.