Development of a 13C-based test for fat absorption in humans

The assessment of fat absorption forms an important part of the diagnostic process in some patients being investigated for possible malabsorption. This study has assessed the use of 13C-triolein as an alternative to the current 14C-triolein test for fat absorption. Initial work required an evaluation of performance characteristics of the isotope ratio mass spectrometer, observations on the normal variation in the exhaled breath 13CO2: 12CO2 ratio over one day, i.e. the effect of food and exercise, the investigation of a number of potential test meals to aid isotope delivery and the effect of 13C dose. A protocol has been developed for a test of fat absorption using 13C-triolein as the marker substrate and lemon mousse as the test meal. [Continues.]