Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Effects of duodenal infusion of lauric acid and L-tryptophan, alone and combined, on fasting glucose, insulin and glucagon in healthy men
Author: McVeay, C.
Fitzgerald, P.C.
Horowitz, M.
Feinle-Bisset, C.
Citation: Nutrients, 2019; 11(11):1-9
Publisher: MDPI
Issue Date: 2019
ISSN: 2072-6643
Statement of
Christina McVeay, Penelope C. E. Fitzgerald, Michael Horowitz and Christine Feinle-Bisset
Abstract: The fatty acid, lauric acid ('C12'), and the amino acid, tryptophan ('Trp'), when given intraduodenally at loads that individually do not affect energy intake, have recently been shown to stimulate plasma cholecystokinin, suppress ghrelin and reduce energy intake much more markedly when combined. Both fatty acids and amino acids stimulate insulin secretion by distinct mechanisms; fatty acids enhance glucose-stimulated insulin secretion, while amino acids may have a direct effect on pancreatic β cells. Therefore, it is possible that, by combining these nutrients, their effects to lower blood glucose may be enhanced. We have investigated the potential for the combination of C12 and Trp to have additive effects to reduce blood glucose. To address this question, plasma concentrations of glucose, insulin and glucagon were measured in 16 healthy, lean males during duodenal infusions of saline (control), C12 (0.3 kcal/min), Trp (0.1 kcal/min), or C12+Trp (0.4 kcal/min), for 90 min. Both C12 and C12+Trp moderately reduced plasma glucose compared with control (p < 0.05). C12+Trp, but not C12 or Trp, stimulated insulin and increased the insulin-to-glucose ratio (p < 0.05). There was no effect on plasma glucagon. In conclusion, combined intraduodenal administration of C12 and Trp reduced fasting glucose in healthy men, and this decrease was driven primarily by C12. The effects of these nutrients on postprandial blood glucose and elevated fasting blood glucose in type 2 diabetes warrant evaluation.
Keywords: amino acid; fatty acid; glycaemic control; blood glucose; humans
Rights: © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (
RMID: 1000005072
DOI: 10.3390/nu11112697
Grant ID:
Appears in Collections:Medicine publications

Files in This Item:
File Description SizeFormat 
hdl_122696.pdfPublished version475.88 kBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.