Comparison of the Efficacy of Saccharomyces Boulardii and Rifaximin in the Treatment of Small Intestinal Bacterial Overgrowth

NCT07815548 | Not Yet Recruiting Phase 4

• 1 other identifier: KYLL-2025-12-010-1
• Study Type: interventional
• Target: 222
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Small Intestinal Bacterial Overgrowth Syndrome (SIBO)

Outcome Measures

Primary Outcomes (1)

• Clinical Effective Rate After Intervention and 1 Month Post-treatment

  Proportion of participants achieving clinical effectiveness, defined as complete relief, major relief or partial relief of abdominal distension and diarrhea symptoms. Clinical effective rate = (number of participants with complete relief + major relief + partial relief) / total number of participants × 100%

  End of 2-week treatment; 1 month after completion of treatment

Secondary Outcomes (6)

• Symptom Relief Rate After Intervention and 1 Month Post-treatment

  End of 2-week treatment; 1 month after completion of treatment

• Change From Baseline in Gastrointestinal Symptom Rating Scale (GSRS) Total Score

  Baseline, end of 2-week treatment, 1 month after completion of treatment

• Incidence of Adverse Events

  From first study drug administration up to 60 days after last study drug dose

• Participant Treatment Adherence Rate

  Throughout the 2-week treatment period

• Proportion of Participants With Comorbid Anxiety and Depression

  Baseline, 1 month after completion of treatment

Study Arms (2)

Saccharomyces boulardii Sachets Treatment Arm

EXPERIMENTAL

Subjects receive Saccharomyces boulardii sachets 0.5 g twice daily orally for 2 weeks

Drug: Saccharomyces boulardii sachets

Rifaximin Treatment Arm

ACTIVE COMPARATOR

Subjects receive rifaximin 0.4 g twice daily orally for 2 weeks

Drug: Rifaximin (Xifaxan)

Interventions

Saccharomyces boulardii sachets DRUG

0.5 g, orally, twice daily for 2 weeks

Saccharomyces boulardii Sachets Treatment Arm

Rifaximin (Xifaxan) DRUG

0.4 g, orally, twice daily for 2 weeks

Rifaximin Treatment Arm

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged between 18 and 70 years, male or female.
• Presenting with chief complaints of abdominal distension and/or diarrhea.
• Diagnosis of small intestinal bacterial overgrowth (SIBO) confirmed by positive hydrogen-methane breath test.

You may not qualify if:

• Pregnant, puerperal, or breastfeeding women.
• Prior history of gastrointestinal malignancy or gastrointestinal surgery.
• Previously diagnosed or suspected lactose intolerance.
• Severe or extremely abnormal anxiety-depression scale scores.
• 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).
• 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.
• Known allergy to study medications.
• Immunosuppressed hospitalized patients or hospitalized patients with immune impairment due to critical illness.
• Unable or unwilling to provide written informed consent.
• History of psychiatric disorders.
• Any other conditions that render the subject inappropriate for participation in this study, as judged by the investigator.

Sponsors & Collaborators

• Shandong University: lead

Study Sites (1)

Qilu Hospital of Shandong University

Jinan, Shandong, 250012, China

Location

MeSH Terms

Interventions

Rifaximin

Intervention Hierarchy (Ancestors)

Rifamycins; Heterocyclic Compounds, 4 or More Rings; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds; Lactams, Macrocyclic; Macrocyclic Compounds; Polycyclic Compounds

Central Study Contacts

Xiuli Zuo

CONTACT

+86-18560080066; zuoxiuli@sdu.edu.cn

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director of Qilu Hospital gastroenterology department

Study Record Dates

• First Submitted: September 8, 2026
• First Posted: September 11, 2026
• Study Start: September 10, 2026
• Primary Completion (Estimated): November 30, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: September 15, 2026

Record last verified: 2026-09

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)