Eradication of the gut microbiota, by treatment with antibiotics, reduced Wnt activity, decreased cell proliferation, and prevented the onset of dysplasia in the ileum and colon of CKIaΔgutp53R172H mice, suggesting that the regional microbiota likely counter the tumour-suppressive activity of mutant p53 in the distal gut thereby promoting tumorigenesis. Here, TP53 is linked to neoplasm.