B. fragilis colonization decreased DSS-induced inflammation and colitis, and decreased size and numbers of AOM/DSS-induced colitis-associated CRC tumors [13]B. fragilis Polysaccharide A (PSA), in TLR2 dependent manner, inhibited proliferation of CRC cells by suppressing cell cycle progression (downregulation of CCND1 and CDK2, upregulation of CDKN1B). PSA suppressed EMT and decreased migration and invasion of CRC cells in vitro [57]. This evidence concerns the gene TLR2 and colitis.