Clinical Research Directory

Inclusion Criteria: * Voluntarily participate in the clinical study, fully understand the study and sign the informed consent form (ICF); willing and able to follow and complete all trial procedures. * Gender unrestricted, age at the time of signing ICF: ≥18 years, ≤80 years. * Diagnosed with a malignant gastrointestinal tumor, including gastric cancer, colorectal cancer, esophageal cancer, and pancreatic cancer, and has undergone radical surgical resection. If necessary, perioperative systemic treatment has been completed by the time of screening. * At the time of screening, a nutritional risk score of ≥3 (based on the NRS 2002 nutritional risk screening tool) . * In good general condition, with an ECOG performance status score of ≤2. * Agree to provide peripheral blood, stool, and urine samples for biomarker analysis during the study period. Exclusion Criteria: * At the time of screening, presence of tumor recurrence or metastasis. * At the time of screening, presence of another active malignancy requiring concurrent treatment. * Expected survival of ≤3 months. * Unable to take oral nutrition, requiring enteral feeding tubes, or having malabsorption syndrome or any condition affecting gastrointestinal absorption; e.g., chronic diarrhea (watery stools; defecation frequency ≥5 times a day). * Patients who are planning a pregnancy, are pregnant, or are breastfeeding. * Allergic to any known components of the trial materials. * Presence of serious primary diseases of the heart, brain, lungs, liver, kidneys, endocrine, hematological, neurological, or other systems, or other acute or chronic diseases that could significantly affect treatment and prognosis. * Presence of other severe physical or mental illnesses or laboratory abnormalities that may increase the risk associated with participation in the study, or patients deemed unsuitable for participation by the researchers.