Medium chain triglycerides activate distal but not proximal gut.pdf

Clinical Nutrition (1999) 18(6): 359-363 ? 1999 Harcottrt Publishers Ltd ORIGINAL ARTICLE Medium chain triglycerides activate distal but not proximal gut hormones M. K. VU, M. VERKIJK, E. S. M. MULLER, I. BIEMOND, C. B. H. W. LAMERS, A. A. M. MASCLEE Department of Gastroenterology-Hepatology, Leiden University Medical Center, the Netherlands (Correspondence to: AAMM, Department of Gastroenterology-Hepatology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.) Abstract--Background and aims: Compared to long chain triglycerides (LCT), medium chain triglycerides (MCT) are considered an attractive caloric source in malabsorptive diseases because of their favorable physico-chemical characteristics. The use of MCT is, however, limited by the occurrence of gastrointestinal symptoms such as diarrhoea. We have, therefore, investigated the effects of MCT and LCT on proximal (cholecystokinin; CCK) and distal (peptide YY; PYY) gut hormone secretion. Methods: Eight healthy volunteers participated in four experiments performed in random order during continuous intraduodenal administration for 360 rain of a) saline (control); b) LCT 15 mmol/h; c) MCT 15 mmol/h (equimolar); d) MCT 30 mmol/h (equicaloric). Plasma CCK and PYY were determined at regular intervals (radioimmunoassay). Duodenocecal transit (DCTT) was measured by lactulose H2 breath test. Results: DCTT during LCT (105 +_ 11 rain) was not significantly different from saline (111 _+ 10 rain). Both low dose MCT (54 + 5 min) and high dose MCT (61 _+ 6 min) significantly accelerated DCTT (P 0.05). Plasma CCK increased significantly (P 0.05) during LCT but not during MCT or saline. PYY increased significantly (P 0.05) not only during LCT, but also during low and high dose MCT but not during saline. Conclusions: Intraduodenal MCTs a) accelerate intestinal transit; b) do not stimulate CCK release; c) but stimulate release of the distal gut hormone PYY. These results suggest t