Breath Test in Healthy Controls

Condition: Small intestinal bacterial overgrowth


Key Inclusion Criteria

  • At least 18 years old

Key Exclusion Criteria

  • History of irritable bowel syndrome
  • History of inflammatory bowel disease
  • History of celiac disease, microscopic colitis, or any other significant gastrointestinal disease

Full Study Name

Elevated Exhaled Hydrogen Sulfide Levels Are Associated With Small Intestinal Bacterial Overgrowth: Pilot Study (IRB no. 54111) 


This study focuses on individuals who do not have a history of small intestinal bacterial overgrowth (SIBO) or its associated symptoms, including abdominal pain, bloating, constipation, or diarrhea. The purpose of the study is to examine the levels of hydrogen sulfide in healthy patients; researchers will evaluate the investigational use of the Integrated Breath Sample System (IBS-S).  

Hydrogen sulfide is a gas that aids in the diagnosis of SIBO, which can be tested via lactulose breath test. Lactulose is a sugar that is digested by bacteria in the small intestine, and in patients with SIBO, this leads to gas and other symptoms. Hydrogen sulfide is produced by the bacteria in the small intestine when it digests the lactulose. Researchers aim to determine normal levels of hydrogen sulfide on the breath so that they are better able to diagnose SIBO.  

Financial Disclosure

  • Mark Pimentel, MD, and Ali Rezaie, MD, who are researchers on this study, have filed a patent, copyright, or other intellectual property directly related to this research. At this time, there is no financial value associated with this filed patent; however, it is possible that the researchers could receive royalty income or may receive future royalty income, should the patent be licensed in the future.
  • Cedars-Sinai owns the patent related to the device being tested.
Principal Investigator

Mark Pimentel, MD


Medically Associated Science and Technology (MAST) Program Office