Gut Function Outcome Measures

The lactulose/rhamnose dual-sugar test is the primary functional assay for intestinal permeability in the trials. Faecal MPO and neopterin are used as markers of neutrophil activation and interferon-gamma-mediated macrophage activation. Plasma iFABP and LPSBP are measured because both are elevated in environmental enteropathy. Complete protein digestion and absorption in the DSIT is indicated when plasma amino acid isotope ratios match the test meal ratio. The dual stable isotope test measures the fraction of protein-derived amino acids from a meal that enter systemic circulation. The ¹³C sucrose breath test assesses sucrase-isomaltase activity, which is suppressed in environmental enteropathy.