Small Intestinal Bacterial Overgrowth Syndrome: A Guide for the Appropriate Use of Breath Testing

Area of Science:

• Gastroenterology
• Diagnostic Medicine
• Microbiology

Background:

• Noninvasive breath tests are widely used for diagnosing small intestinal bacterial overgrowth (SIBO) in patients with gastrointestinal issues.
• The lactulose breath test (LBT) has limitations, leading to potential over-diagnosis of SIBO and unnecessary antibiotic treatments.
• Current diagnostic practices require refinement for accurate SIBO identification.

Purpose of the Study:

• To critically evaluate the utility of breath tests for diagnosing SIBO.
• To propose guidelines for the optimal use and interpretation of the glucose breath test (GBT) for SIBO diagnosis.
• To recommend the discontinuation of the LBT due to its flawed methodology.

Main Methods:

• Review of existing literature on breath tests for SIBO.
• Analysis of the underlying principles and limitations of LBT and GBT.
• Development of evidence-based recommendations for SIBO testing.

Main Results:

• The LBT is based on an incorrect premise, resulting in SIBO over-diagnosis and increased antibiotic prescriptions.
• The GBT, despite limitations, is a more appropriate choice for SIBO diagnosis in selected patients.
• Significant discrepancies exist in the literature due to reliance on the LBT.

Conclusions:

• The LBT should be abandoned for SIBO diagnosis.
• The GBT is the preferred breath test for suspected SIBO when used judiciously.
• Clinical practice and research literature should transition away from LBT-based findings.