TNF and colitis: No differences in the severity of intestinal inflammation were found between colonized and non-colonized rats based on measurements of TNFα and IL1β relative gene expression (Figures 2A,C), weight (Figure 2E), clinical data (Table 1), and macroscopic observation of the intestine (the length of inflamed intestine was in average 16cm after colitis induction in both groups; Figures 3A,B).