Previous studies have shown that NOD2 gene mutants were associated with the Crohn's disease (CD), colorectal cancer (CRC) and many other diseases, suggesting the critical role of NOD2 signaling in human physiology and pathogenethesis. However, whether decreased NOD2 ligands also contributed to these diseases is unknown. In this study, the investigators plan to evaluate the change of NOD2 ligands in inflammatory bowel diseases (IBD), CRC, atherosclerotic cardiovascular disease (ACVD), and type 2 diabetes mellitus (DM2 ). For each of the patient, a sex- and age- matched control were chosen. Both the targeted metabolomics (LC-MS-MS methods) and NOD2-transfected cells co-expressing NF-κB luciferase reporters were used to test NOD2 ligands in the fecal and plasma samples.