High-Fermented Food Intervention Among Locally Advanced Rectal Cancer Patients (The FEED Trial)

The purpose of the study is to evaluate the feasibility and acceptability of a dietary intervention (FEED-FF) that includes fermented foods (FF), among locally advanced rectal cancer patients and non-small cell lung cancer (NSCLC) patients, and to explore whether this diet can improve outcomes in rectal cancer patients receiving chemoradiation and NSCLC patients receiving immunotherapy.

Inclusion Criteria for GI Patients: * 18 years of age or older * Diagnosed with locally advanced rectal cancer (Stage II-III) * Will undergo neoadjuvant chemoradiation at Moffitt Cancer Center * Able to pick up FFs once/weekly at Moffitt * Able to speak and read English * Able to consume foods orally * Able to provide informed consent Inclusion Criteria for Thoracic Patients: * 18 years of age or older * Diagnosed with stage II-IV non-small cell lung cancer (NSCLC) * Will undergo Immunotherapy with immune checkpoint inhibitors (+/- chemotherapy or other treatment) at Moffitt Cancer Center * Able to pick up FFs once/weekly at Moffitt * Able to speak and read English * Able to consume foods orally * Able to provide informed consent Exclusion Criteria: * Antibiotic use within 1 month prior to baseline * If currently using probiotics, unwillingness to cease probiotic use * Previous receipt of surgery, immunotherapy, chemotherapy, or radiation for a colon or rectal tumor * Per clinician's discretion, clinician confirmed inflammatory bowel conditions (e.g., ulcerative colitis, Crohn's disease) * Infectious disease diagnosed \