Inclusion Criteria:
1. Pre-advanced or advanced tumor cachexia stage.
2. Age ≥ 18 years old, ECOG score 0-2, expected survival \> 3 months.
3. Patients with gastric cancer, colorectal cancer, or lung cancer who have received second-line or higher treatment.
4. No FMT treatment in the past six months.
Exclusion Criteria:
1. Any condition that affects gastrointestinal absorption, such as difficulty in swallowing, malabsorption, or uncontrollable vomiting; undergoing tube feeding or parenteral nutrition.
2. Neurotic anorexia, anorexia caused by mental illness, or difficulty in eating due to pain.
3. Acquired immunodeficiency syndrome.
4. Currently taking or planning to take other drugs that increase appetite or weight, such as adrenal corticosteroids (except for short-term use of dexamethasone during chemotherapy), androgens, progestogens, salidroside, olanzapine, and anamorin or other appetite stimulants.
5. Patients with Cushing's syndrome, adrenal or pituitary insufficiency; patients with difficult-to-control diabetes.
6. Current imaging or clinical manifestations of gastrointestinal obstruction.
7. Current uncontrolled coexisting diseases, including but not limited to decompensated cirrhosis, renal failure, uncontrolled metabolic disorders, severe active peptic ulcer disease or gastritis, or mental illnesses/societal conditions that may limit patient compliance with study requirements or affect the patient's ability to provide written informed consent.
8. Within 12 months prior to the first administration, there was unstable angina pectoris, myocardial infarction, congestive heart failure (grade 2 or above according to the New York Heart Association functional classification), or vascular diseases (such as aneurysms with a risk of rupture), or other cardiac damages that may affect the safety evaluation of the study drug (such as poorly controlled arrhythmias, myocardial ischemia); within 6 months prior to the first administration, there was esophageal-gastric varices, severe ulcers, gastrointestinal perforation and/or fistula history, history of gastrointestinal obstruction (including incomplete intestinal obstruction requiring parenteral nutrition), intra-abdominal abscess or history of acute gastrointestinal bleeding.
9. Within 4 weeks prior to the first administration, a serious infection occurred, including but not limited to conditions requiring hospitalization.
