Comparison of the Efficacy of Saccharomyces Boulardii and Rifaximin in the Treatment of Small Intestinal Bacterial Overgrowth：a Non-inferiority Randomized Controlled Study

Comparison of the Efficacy of Saccharomyces Boulardii and Rifaximin in the Treatment of Abdominal Distension and Diarrhea Related to Small Intestinal Bacterial Overgrowth：a Non-inferiority Randomized Controlled Study

This multicenter randomized controlled study aims to systematically evaluate the efficacy and safety of Saccharomyces boulardii sachets versus rifaximin in the treatment of small intestinal bacterial overgrowth (SIBO), with a focus on symptom relief and the impacts of anxiety-depressive factors on the treatment of abdominal distension and diarrhea in SIBO patients. The findings will offer a new non-antibiotic therapeutic option for SIBO, especially for patients with antibiotic resistance or those requiring long-term management, and lay a theoretical foundation for the clinical application of intestinal microecological regulators.

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.