Fat absorption in persistent diarrhoea using 13C-labelled trioctanoin breath test

Abstract

A study was undertaken to investigate intestinal fat absorption in young children suffering from persistent diarrhoea in comparison with normal children of similar age. Absorption studies were performed using the breath test technique. Following oral administration of labelled triglyceride ([13C]trioctanoin), interval breath sampling was done for 6 h. The time course of excretion of 13CO2 in the breath was determined by isotope ratio mass spectrometric analysis of the gas samples. Excretion curves were constructed from the mean values of 13CO2 dose (per cent) excreted at each time point in breath samples and areas under the curve were determined for diarrhoea cases as well as for normal subjects. The time course of 13CO2 excretions and areas under the curve thus obtained were compared with each other and also with a reference study in which data from known malabsorption cases were available. The time of peak 13CO2 excretion in diarrhoea cases ranged from 60 to 240 min (average 150 min) compared with 120 to 270 min (average 195 min) for normal subjects, the level of peak of 13CO2 excreted/h was 4.8 +/- 1.2 per cent in diarrhoea cases and 5.3 +/- 2.3 per cent in normal children (NS). Mean areas under the curve for the two groups were 18.9 +/- 3.4 per cent for normal and 17.6 +/- 4.1 per cent dose 13CO2 excreted/6 h for diarrhoea cases (NS). These results indicate that intestinal absorption of medium chain triglycerides was not impaired significantly in the cases of persistent diarrhoea studied.