13C mannitol as a novel biomarker for measurement of intestinal permeability

Abstract

Background: Gastrointestinal (GI) and non-GI disorders are associated with altered intestinal permeability, which can be measured in vivo by urinary excretion after oral lactulose and mannitol ingestion. Inadvertent dietary consumption of 12Carbon (12C, regular) mannitol in food or from other sources may interfere with the test's interpretation. 13Carbon (13C) constitutes 1% of carbon in nature and 13C mannitol is a stable isotope. Our aim was to determine the performance of 13C mannitol for measurement of intestinal permeability. Methods: Ten healthy volunteers underwent intestinal permeability assay using coadministered 12C mannitol, 13C mannitol and lactulose, followed by timed urine collections. Urinary sugar concentrations were measured using tandem high performance liquid chromatography–mass spectrometry. Key results: We found that 13C mannitol can be distinguishable from 12C mannitol on tandem mass spectrometry. In addition, 13C mannitol had ~20-fold lower baseline contamination compared to 12C mannitol. We describe here the 13C mannitol assay method for the measurement of intestinal permeability. Conclusions & Inferences: In conclusion, 13C mannitol is superior to 12C mannitol for measurement of intestinal permeability. It avoids issues with baseline contamination and erratic excretions during the testing period.