Gastrointestinal handling and metabolic disposal of C-13-labelled tripalmitin during rehabilitation from childhood malnutrition

We investigated the gastrointestinal handling and post-absorptive metabolic handling of [1,1,1-C-13]tripalmitin and [1-C-13]glycocholate during recove ry from severe childhood malnutrition. Eight children were studied on three occasions: at admission (phase 1), during rapid catch-up growth (phase 2) and when weight-for-height had reached 90 % of the reference (phase 3). Bre ath samples were obtained over a 24 h period and stools were collected over 3 d following the administration of each tracer. At admission, the lipid c ontent of stool expressed as a percentage of ingested lipid was 6 (range 0. 7-28.9) but less variation was shown between children at phase 2 (3.3 (rang e 0.9-4.1)) and phase 3 (1.4 (range 0.4-2.5)). The excretion of C-13 in sto ol varied markedly between children at admission (11.1 (sd 5.4) % administe red dose) and during rehabilitation (phase 2, 15.4 (sd 16.5) % administered dose; phase 3, 6.2 (sd 10.2) % administered dose). About 5 % of the absorb ed label was recovered on breath at each stage (% absorbed dose; phase 1, 5 .1 (sd 6.0); phase 2, 5.2 (sd 3.1); phase 3, 6.4 (sd 6.6)). None of the chi ldren exhibited significant bile salt malabsorption as a consequence of sma ll intestinal overgrowth. Of the C-13 measured in stool, more label was rec overed in fatty acids than triacylglycerols during each of the three phases and this was interpreted to reflect a failure to absorb the products of di gestion. The results show that not all the children had problems associated with the digestion and absorption of C-13-labelled tripalmitin in severe m alnutrition and during recovery, which was not reflected in gross lipid bal ance across the gastrointestinal tract. Absorbed lipid was more likely to b e deposited as adipose tissue than to satisfy the immediate needs for energ y.