Clinical Research Directory

Inclusion Criteria: 1. patients undergoing thoracic surgery under general anesthesia with 48 h of postoperative patient-controlled analgesia; 2. age ≥60 years; 3. ASA class I-III; 4. signed informed consent; 5. patients undergoing thoracoscopic surgery. Exclusion Criteria: 1. Patients who themselves refuse to participate in the study; 2. Drug dependence; 3. Patients who cannot cooperate with communication and have verbal communication difficulties; 4. Patients who cannot assess frailty preoperatively and pain postoperatively; 5. Failure to provide a compliant fecal sample at the agreed time; 6. antibiotic treatment within the last month; 7. intestinal dysfunction (e.g., irritable bowel syndrome, inflammatory bowel disease, chronic diarrhea, and other types of intestinal disorders); 8. comorbidities of certain metabolic disorders (e.g., thyroid dysfunction, diabetes mellitus, and so on) that may affect the structure of the microbial community;