Inclusion Criteria:  Males or females. Age: 45-70 years, inclusive. Patients without any incapacitating systemic disease Able to comprehend and provide informed consent. Patients who are scheduled / planned to undergo a colonoscopy, preferably: participants who are undergoing a colonoscopy as a diagnostic surveillance.  Exclusion Criteria:  Subject has a history of colorectal cancer (CRC)  Subject has a diagnosis or medical history of any of the following conditions:  Familial adenomatous polyposis (also referred to as "FAP", including attenuated FAP and Gardner's syndrome) Hereditary non-polyposis CRC syndrome (also referred to as "HNPCC" or "Lynch Syndrome") Subject has a diagnosis or personal history of inflammatory bowel disease (IBD), including chronic ulcerative colitis or Crohn's disease. Patients with incapacitating systemic disease Any use of antibiotics within one months prior to colonoscopy.