Fecal Microbiota Transplantation (FMT) in Patients With Moderate to Severe Acute Pancreatitis

Inclusion Criteria: Age: 18-70 years old Diagnosis: Meets the diagnostic criteria for severe acute pancreatitis (SAP) * Organ function: There may be organ failure and systemic complications that can be recovered within 48 hours * Stage of the disease: Approximately 2 weeks after onset (non acute phase), accompanied by accumulation of pancreatic fluid volume, and significant improvement in CTSI score compared to before (grade II) * Nutritional support: Enteral nutrition tube has been left in place Feasibility of transplantation: No absolute contraindications for gut microbiota transplantation * Informed Consent: Voluntarily sign a written informed consent form * Gastrointestinal status: Abdominal pressure (bladder pressure measurement)\<12mmHg ◦ Existence of spontaneous defecation/exhaust Significant improvement in abdominal distension compared to before Exclusion Criteria: Serious complications: combined gastrointestinal bleeding or intestinal fistula * Special population: Pregnant or lactating women * Informed refusal: Failure to sign informed consent form * Basic organ dysfunction: Prior to admission, there were chronic organ dysfunction in the heart, lungs, liver, kidneys, or blood system Malignant tumor: Suffering from incurable malignant tumors * Immune abnormalities: Autoimmune diseases ◦ Immunosuppression status (solid organ/bone marrow transplantation history, AIDS, long-term use of immunosuppressants/hormones) * Enteral nutrition intolerance: unable to meet 50% of calorie requirements due to severe diarrhea, fibrotic intestinal stenosis, severe gastrointestinal edema, high flow intestinal fistula, etc * Systemic infection: meets the diagnostic criteria for systemic inflammatory response syndrome (SIRS) * Antibiotic dependence: broad-spectrum antibiotic intervention is required for combined extraintestinal organ infections * Immunodeficiency: Congenital or acquired immunodeficiency * Mental illness: severe mental disorders