Extended Data Fig. 1: Co-culture with genotoxic pks⁺ E. coli induces DNA interstrand crosslinks in healthy human intestinal organoids.

a, Representative images (out of n = 5 organoids per group) of DNA interstrand crosslink formation after 1 day of co-culture, measured by FANCD2 immunofluorescence (green). Nuclei were stained with DAPI (blue). Yellow boxes represent inset area. Scale bars, 50 μm (main image); 10 μm (inset). Experiment was repeated independently twice with similar results. b, Gating strategy to select epithelial cells (left) and to quantify viable cells (right). c, Mean ± s.d. viability of intestinal organoid cells after 1, 3 or 5 days of co-culture (n = 3 technical replicates) (bacteria eliminated after 3 days of co-culture). Points are independent replicates.