Effects of S. Boulardii and Amoxicillin/Clavulanate on Gut Microbiota

This study has been completed.
Information provided by (Responsible Party):
Beth Israel Deaconess Medical Center
ClinicalTrials.gov Identifier:
First received: November 15, 2011
Last updated: July 22, 2014
Last verified: July 2014
The purpose of this study is to compare and contrast the effects of the probiotic Saccharomyces boulardii, the antibiotic amoxicillin/clavulanate and the combination on the gut microbiota of healthy volunteers.

Condition Intervention
Healthy Volunteers
Dietary Supplement: Saccharomyces boulardii
Drug: Amoxicillin Clavulanate
Drug: Saccharomyces boulardii AND Amoxicillin Clavulanate

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Open Label, Randomized Pilot Study to Examine The Effects of the Probiotic Saccharomyces Boulardii, the Antibiotic Amoxicillin/Clavulanate and the Combination on the Gut Microbiota of Healthy Volunteers

Resource links provided by NLM:

Further study details as provided by Beth Israel Deaconess Medical Center:

Primary Outcome Measures:
  • Change in microbiome quantity [ Time Frame: Days -28 to -7, 0, 3, 6, 10, 13, 21 ] [ Designated as safety issue: No ]
    Change in total numbers of bacteria in stool samples over the course of the study

  • Change in microbiome diversity [ Time Frame: Days -28 to -7, 0, 3, 6, 10, 13, 21 ] [ Designated as safety issue: No ]
    Change in total numbers of bacterial strains in stool samples as determined by operational taxonomic units over the course of the study

Enrollment: 53
Study Start Date: April 2012
Study Completion Date: February 2013
Primary Completion Date: February 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: prebiotic (Saccharomyces boulardii) Dietary Supplement: Saccharomyces boulardii
500 mg, 2 times daily for 14 days
Active Comparator: antibiotic (Amoxicillin Clavulanate) Drug: Amoxicillin Clavulanate
875/125 mg 2 times daily at least 1 hour before meals for 7 days
Active Comparator: combination (prebiotic and antibiotic) Drug: Saccharomyces boulardii AND Amoxicillin Clavulanate
Amoxicillin Clavulanate for 7 days (days 1 to 7; 875/125 mg 2 times daily at least 1 hour before meals) in addition to the dietary supplement Saccharomyces boulardii for 14 days (days 1 to 14; 500 mg, 2 times daily).
No Intervention: control


Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age 18 to 65 years (male or female)
  • Good general health
  • Able to comply with study requirements and to provide informed consent
  • For women of childbearing potential oA negative urine pregnancy test immediately prior to starting the study treatment oAgreement to comply with approved methods of contraception during the period of active study treatment (not required during follow-up)

Exclusion Criteria:

  • History of organ transplantation
  • Known chronic or recurrent systemic disorder associated with immunocompromise
  • A history of allergy or hypersensitivity to Saccharomyces boulardii, brewer's or baker's yeast, amoxicillin, penicillins, or cephalosporins
  • History of severe allergic reaction (requiring hospital admission and/or the administration of parenteral medication or associated with dyspnoea, wheezing, hypotension, loss of consciousness).
  • Oral or systemic antibacterial therapy during the 3 months prior to study enrollment
  • New prescription medications during the 4 weeks prior to study enrollment
  • Prescription, OTC medications or supplements that are known to alter gut function or microflora (i.e. acid antisecretory drugs, probiotics) during the 4 weeks prior to study enrollment
  • Active gastrointestinal disease
  • Patients with a central venous catheter
  • Patients taking antifungals or laxatives within 14 days of enrolment
  • Patients enrolled in other clinical trials within the past 60 days
  • Prior gastrointestinal surgery (apart from appendectomy or cholecystectomy)
  • History of chronic constipation with passage of fewer than 3 bowel movements per week on average
  • Any condition or personal circumstance that, in the opinion of the investigator, renders the subject unlikely or unable to comply with the full study protocol.
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01473368

United States, Massachusetts
Beth Israel Deaconess Medical Center
Boston, Massachusetts, United States, 02215
Sponsors and Collaborators
Beth Israel Deaconess Medical Center
Principal Investigator: Ciaran P Kelly, MD Beth Israel Deaconess Medical Center
  More Information

Responsible Party: Beth Israel Deaconess Medical Center
ClinicalTrials.gov Identifier: NCT01473368     History of Changes
Other Study ID Numbers: 2011-P-000389-Bioclinica 
Study First Received: November 15, 2011
Last Updated: July 22, 2014
Health Authority: United States: Institutional Review Board
United States: Office for Human Research Protections (HHS)

Keywords provided by Beth Israel Deaconess Medical Center:
human Gut Microbiota
gut microbiota
gut microbiome
antibiotic-associated diarrhea
intestinal bacterial overgrowth

Additional relevant MeSH terms:
Anti-Bacterial Agents
Clavulanic Acid
Clavulanic Acids
Amoxicillin-Potassium Clavulanate Combination
Antibiotics, Antitubercular
Anti-Infective Agents
Antitubercular Agents
Beta-Lactamase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action

ClinicalTrials.gov processed this record on August 23, 2016