Clinical Research Directory

Inclusion Criteria: 1. Aged between 18 and 70 years, male or female. 2. Presenting with chief complaints of abdominal distension and/or diarrhea. 3. Diagnosis of small intestinal bacterial overgrowth (SIBO) confirmed by positive hydrogen-methane breath test. Exclusion Criteria: 1. Pregnant, puerperal, or breastfeeding women. 2. Prior history of gastrointestinal malignancy or gastrointestinal surgery. 3. Previously diagnosed or suspected lactose intolerance. 4. Severe or extremely abnormal anxiety-depression scale scores. 5. Confirmed extra-digestive system diseases, including urinary system diseases (e.g., chronic kidney disease), immune system diseases (e.g., scleroderma), nervous system diseases (e.g., Parkinson's disease), and endocrine system diseases (e.g., diabetes mellitus). 6. Use of antibiotics or microecological preparations within 2 weeks before enrollment; receiving endoscopy, enema, or colonic barium-air contrast examination within 2 weeks before enrollment; use of prokinetics, secretagogues, antifoaming agents, antispasmodics, opioids, or antidepressants within 1 week before enrollment. 7. Known allergy to study medications. 8. Immunosuppressed hospitalized patients or hospitalized patients with immune impairment due to critical illness. 9. Unable or unwilling to provide written informed consent. 10. History of psychiatric disorders. 11. Any other conditions that render the subject inappropriate for participation in this study, as judged by the investigator.