clbM is essential for NC101-induced genotoxic response in vivo.

a, NC101 (n = 6) and ΔclbM (n = 8) colonize to similar levels in the mouse intestine. Eight days after gavage with NC101 or ΔclbM, mouse stools were plated on MacConkey agar to enumerate Enterobacteriaceae. No Enterobacteriaceae were cultured from control mice (n = 5). b, Immunohistochemistry analysis reveals significantly less γH2AX induction in the colon of mice colonized by ΔclbM than in those colonized by NC101. Scale bars, 50µm. Right: each symbol represents data from one mouse. The mouse colonization experiment was repeated once. c, NC101 and ΔclbM (red fluorescence-labelled) colonize to similar levels in the 6 d.p.f. zebrafish intestine. Blue is DAPI counterstain. Each symbol represents data from a pool of three zebrafish guts. A total of 18 fish guts from three independent experiments were analysed for each group. NS, not significant; *P < 0.05 and **P < 0.01, two-tailed t-test. Error bars indicate s.d.