Manipulation of the Gut Microbiome by a Standardized Preoperative Diet to Prevent Colorectal Cancer Recurrence and Metastasis Following Surgery

Inclusion Criteria: * Must have histologically or cytologically confirmed colorectal adenocarcinoma. * Planned for primary tumor resection at the University of Chicago Medicine ≥21 from date of obtained informed consent. Patients with metastatic disease but undergoing primary site resection are eligible for the study. * Age ≥18 years. * Patients \<18 years of age, children are excluded from this study, because they have unique nutritional requirements that might not be met by with the standardized diet. The food in the diet is designed for adults and would not be feasible for children, especially those attending school. In addition, colon cancer is extremely rare in children. * May have received neoadjuvant therapy (chemotherapy, radiation). * Patients with Hepatic arterial infusion (HAI) pumps are considered eligible. * Ability to understand and willing to sign an informed consent, participate in the dietary intervention, collect stools, donate blood, and complete a pre-nutritional evaluation and compliance/patient satisfaction survey. Exclusion Criteria: * Previous ostomy (ileostomy or colostomy) or definitive plan for an ostomy (ileostomy or colostomy) during the procedure. * Antibiotic exposure within 60 days before diet initiation. Antibiotic exposure is defined as a 'course of treatment to treat an infection'. Prophylactic antibiotics prior to a procedure is okay. * Prebiotic/Probiotic exposure within 60 days before diet initiation. * Concomitant separate malignancy. * Allergy to perioperative medications (oral neomycin/metronidazole for bowel preparation, intraoperative prophylactic intravenous cefazolin and metronidazole). * Patients who are pregnant are not eligible for the study. Pregnant women are excluded from this study because the preoperative diet is not specifically formulated to meet the specific nutritional requirements during the prenatal period. * History of inflammatory bowel disease * Severe food allergies precluding the ability to tolerate the standardized dietary intervention. * Patients with uncontrolled intercurrent illness