CEACAM6 and colitis: Allelic replacement of the fimH gene in the AIEC LF82 genetic background by fimH from strains belonging to the FimH consensus clade (non-pathogenic E. coli K12 and LF28) significantly decreased the ability of bacteria to colonize the gut mucosa of transgenic CEABAC10 mice expressing human CEACAM6 and consequently decreased the ability of AIEC bacteria to trigger colitis (weight loss, diarrhea, presence of blood in stools), histological damage to intestinal mucosa and pro-inflammatory interleukin 1-beta secretion by the colonic loop.