TY - JOUR
T1 - Effect of L-Tryptophan and L-Leucine on Gut Hormone Secretion, Appetite Feelings and Gastric Emptying Rates in Lean and Non-Diabetic Obese Participants
T2 - A Randomized, Double-Blind, Parallel-Group Trial
AU - Meyer-Gerspach, Anne Christin
AU - Häfliger, Simon
AU - Meili, Julian
AU - Doody, Alison
AU - Rehfeld, Jens F
AU - Drewe, Jürgen
AU - Beglinger, Christoph
AU - Wölnerhanssen, Bettina K
PY - 2016/11
Y1 - 2016/11
N2 - Background/Objectives Gut hormones such as cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) play a role as satiation factors. Strategies to enhance satiation peptide secretion could provide a therapeutic approach for obesity. Carbohydrates and lipids have been extensively investigated in relation to peptide release. In contrast, the role of proteins or amino acids is less clear. Our aim was to compare the effects of the amino acids L-tryptophan (L-trp) and L-leucine (L-leu) separately on gastric emptying and gut peptide secretion. Participants/Methods The study was conducted as a randomized (balanced), double-blind, parallel-group trial. A total of 10 lean and 10 non-diabetic obese participants were included. Participants received intragastric loads of L-trp (0.52 g and 1.56 g) and L-leu (1.56 g), dissolved in 300 mL tap water; 75 g glucose and 300 mL tap water served as control treatments. Results Results of the study are: I) L-trp at the higher dose stimulates CCK release (p = 0.0018), and induces a significant retardation in gastric emptying (p = 0.0033); ii) L-trp at the higher dose induced a small increase in GLP-1 secretion (p = 0.0257); iii) neither of the amino acids modulated subjective appetite feelings; and iv) the two amino acids did not alter insulin or glucose concentrations. Conclusions L-trp is a luminal regulator of CCK release with effects on gastric emptying, an effect that could be mediated by CCK. L-trp's effect on GLP-1 secretion is only minor. At the doses given, the two amino acids did not affect subjective appetite feelings.
AB - Background/Objectives Gut hormones such as cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) play a role as satiation factors. Strategies to enhance satiation peptide secretion could provide a therapeutic approach for obesity. Carbohydrates and lipids have been extensively investigated in relation to peptide release. In contrast, the role of proteins or amino acids is less clear. Our aim was to compare the effects of the amino acids L-tryptophan (L-trp) and L-leucine (L-leu) separately on gastric emptying and gut peptide secretion. Participants/Methods The study was conducted as a randomized (balanced), double-blind, parallel-group trial. A total of 10 lean and 10 non-diabetic obese participants were included. Participants received intragastric loads of L-trp (0.52 g and 1.56 g) and L-leu (1.56 g), dissolved in 300 mL tap water; 75 g glucose and 300 mL tap water served as control treatments. Results Results of the study are: I) L-trp at the higher dose stimulates CCK release (p = 0.0018), and induces a significant retardation in gastric emptying (p = 0.0033); ii) L-trp at the higher dose induced a small increase in GLP-1 secretion (p = 0.0257); iii) neither of the amino acids modulated subjective appetite feelings; and iv) the two amino acids did not alter insulin or glucose concentrations. Conclusions L-trp is a luminal regulator of CCK release with effects on gastric emptying, an effect that could be mediated by CCK. L-trp's effect on GLP-1 secretion is only minor. At the doses given, the two amino acids did not affect subjective appetite feelings.
KW - Journal Article
U2 - 10.1371/journal.pone.0166758
DO - 10.1371/journal.pone.0166758
M3 - Journal article
C2 - 27875537
SN - 1932-6203
VL - 11
JO - PLoS Computational Biology
JF - PLoS Computational Biology
IS - 11
M1 - e0166758
ER -
