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Physician-scientists at IU School of Medicine conduct ground-breaking research studies to understand small intestinal bacterial overgrowth.

Small Intestinal Bacterial Overgrowth Research Studies

Small intestinal bacteria overgrowth (SIBO) is a condition in which too many bacteria grow in the upper part of the small intestine.  Symptom occur after eating because the bacteria in the intestine begin to consume the food in the small intestine before it can be absorbed. The bacteria then produce gases, which can cause bloating and abdominal distension. In severe SIBO from colon bacteria, patients can suffer from diarrhea, weight loss, nutrition and vitamin malabsorption.


5018-Nelson, David

David E. Nelson, PhD

Professor of Microbiology & Immunology

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5155-Siwiec, Robert

Robert M. Siwiec, MD

Associate Professor of Clinical Medicine

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5144-Wo, John

John M. Wo, MD

Douglas Rex Professor of Gastroenterology and Hepatology

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Open Research Studies for Small Intestinal Bacterial Overgrowth

Small Intestinal Bacterial Overgrowth (SIBO): A Prospective Clinical and Molecular Registry

Image Showing Luminal Aspiration Sample

Enrolling: Yes

Principle Investigator: John M. Wo, MD

Primary Outcomes Measured: To determine the prevalence of risk factors of SIBO in patients with coliform SIBO and aerodigestive tract SIBO.

Secondary Outcomes Measured:

  1. A registry of patients undergoing proximal jejunal aspiration for suspected SIBO to collect data on demographics, SIBO symptom scores, clinical complications, presence of functional gastrointestinal disorders, and vitamin and nutrient deficiencies.
  2. Characterize the clinical differences between coliform SIBO and aerodigestive tract SIBO.
  3. Compare the composition between luminal and mucosal bacteria in the proximal small bowel
  4. Pie Chart Showing Small Intestinal Bacterial Overgrowth Data
  5. Compare the results of bacteria species from molecular identification between luminal aspiration samples and mucosa biopsy samples.


Interested in this study? Please contact the coordinator:
Kara Murphy


Anita Gupta

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