scholarly journals Effects of Duodenal Infusion of Lauric Acid and L-Tryptophan, Alone and Combined, on Fasting Glucose, Insulin and Glucagon in Healthy Men

Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2697 ◽  
Author(s):  
Christina McVeay ◽  
Penelope C. E. Fitzgerald ◽  
Michael Horowitz ◽  
Christine Feinle-Bisset
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Insulin Secretion ◽  
Blood Glucose ◽  
Energy Intake ◽  
Lauric Acid ◽  
Fasting Glucose ◽  
Postprandial Blood Glucose ◽  
Saline Control ◽  
Healthy Men

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.

scholarly journals Intraduodenal Administration of L-Valine Has No Effect on Antropyloroduodenal Pressures, Plasma Cholecystokinin Concentrations or Energy Intake in Healthy, Lean Men

Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 99 ◽  
Author(s):  
Rachel A. Elovaris ◽  
Penelope C. E. Fitzgerald ◽  
Vida Bitarafan ◽  
Sina S. Ullrich ◽  
Michael Horowitz ◽  
...  
Keyword(s):  
Amino Acids ◽  
Blood Glucose ◽  
Energy Intake ◽  
Branched Chain Amino Acids ◽  
World Health ◽  
Postprandial Blood Glucose ◽  
Saline Control ◽  
Intraduodenal Infusion ◽  
Plasma Cholecystokinin ◽  
Branched Chain

Whey protein is rich in the branched-chain amino acids, L-leucine, L-isoleucine and L-valine. Thus, branched-chain amino acids may, at least in part, mediate the effects of whey to reduce energy intake and/or blood glucose. Notably, 10 g of either L-leucine or L-isoleucine, administered intragastrically before a mixed-nutrient drink, lowered postprandial blood glucose, and intraduodenal infusion of L-leucine (at a rate of 0.45 kcal/min, total: 9.9 g) lowered fasting blood glucose and reduced energy intake from a subsequent meal. Whether L-valine affects energy intake, and the gastrointestinal functions involved in the regulation of energy intake, as well as blood glucose, in humans, is currently unknown. We investigated the effects of intraduodenally administered L-valine on antropyloroduodenal pressures, plasma cholecystokinin, blood glucose and energy intake. Twelve healthy lean men (age: 29 ± 2 years, BMI: 22.5 ± 0.7 kg/m2) were studied on 3 separate occasions in randomised, double-blind order. Antropyloroduodenal pressures, plasma cholecystokinin, blood glucose, appetite perceptions and gastrointestinal symptoms were measured during 90-min intraduodenal infusions of L-valine at 0.15 kcal/min (total: 3.3 g) or 0.45 kcal/min (total: 9.9 g), or 0.9% saline (control). Energy intake from a buffet-meal immediately after the infusions was quantified. L-valine did not affect antral, pyloric (mean number; control: 14 ± 5; L-Val-0.15: 21 ± 9; L-Val-0.45: 11 ± 4), or duodenal pressures, plasma cholecystokinin (mean concentration, pmol/L; control: 3.1 ± 0.3; L-Val-0.15: 3.2 ± 0.3; L-Val-0.45: 3.0 ± 0.3), blood glucose, appetite perceptions, symptoms or energy intake (kcal; control: 1040 ± 73; L-Val-0.15: 1040 ± 81; L-Val-0.45: 1056 ± 100), at either load (p > 0.05 for all). In conclusion, intraduodenal infusion of L-valine, at loads that are moderately (3.3 g) or substantially (9.9 g) above World Health Organization valine requirement recommendations, does not appear to have energy intake- or blood glucose-lowering effects.

scholarly journals Intragastric administration of the bitter tastant quinine lowers the glycemic response to a nutrient drink without slowing gastric emptying in healthy men

2020 ◽  
Vol 318 (2) ◽  
pp. R263-R273 ◽  
Author(s):  
Vida Bitarafan ◽  
Penelope C. E. Fitzgerald ◽  
Tanya J. Little ◽  
Wolfgang Meyerhof ◽  
Karen L. Jones ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Gastric Emptying ◽  
Energy Intake ◽  
Plasma Glucose ◽  
Postprandial Blood Glucose ◽  
Intragastric Administration ◽  
Glycemic Response ◽  
Experimental Conditions ◽  
Double Blind ◽  
Healthy Men

The rate of gastric emptying and the release of gastrointestinal (GI) hormones are major determinants of postprandial blood-glucose concentrations and energy intake. Preclinical studies suggest that activation of GI bitter-taste receptors potently stimulates GI hormones, including glucagon-like peptide-1 (GLP-1), and thus may reduce postprandial glucose and energy intake. We evaluated the effects of intragastric quinine on the glycemic response to, and the gastric emptying of, a mixed-nutrient drink and the effects on subsequent energy intake in healthy men. The study consisted of 2 parts: part A included 15 lean men, and part B included 12 lean men (aged 26 ± 2 yr). In each part, participants received, on 3 separate occasions, in double-blind, randomized fashion, intragastric quinine (275 or 600 mg) or control, 30 min before a mixed-nutrient drink ( part A) or before a buffet meal ( part B). In part A, plasma glucose, insulin, glucagon, and GLP-1 concentrations were measured at baseline, after quinine alone, and for 2 h following the drink. Gastric emptying of the drink was also measured. In part B, energy intake at the buffet meal was quantified. Quinine in 600 mg (Q600) and 275 mg (Q275) doses alone stimulated insulin modestly ( P < 0.05). After the drink, Q600 and Q275 reduced plasma glucose and stimulated insulin ( P < 0.05), Q275 stimulated GLP-1 ( P < 0.05), and Q600 tended to stimulate GLP-1 ( P = 0.066) and glucagon ( P = 0.073) compared with control. Quinine did not affect gastric emptying of the drink or energy intake. In conclusion, in healthy men, intragastric quinine reduces postprandial blood glucose and stimulates insulin and GLP-1 but does not slow gastric emptying or reduce energy intake under our experimental conditions.

scholarly journals Comparative Effects of the Branched-Chain Amino Acids, Leucine, Isoleucine and Valine, on Gastric Emptying, Plasma Glucose, C-Peptide and Glucagon in Healthy Men

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1613
Author(s):  
Rachel A. Elovaris ◽  
Vida Bitarafan ◽  
Shahram Agah ◽  
Sina S. Ullrich ◽  
Kylie Lange ◽  
...  
Keyword(s):  
Amino Acids ◽  
Blood Glucose ◽  
Gastric Emptying ◽  
Plasma Glucose ◽  
Branched Chain Amino Acids ◽  
Postprandial Blood Glucose ◽  
Intragastric Administration ◽  
C Peptide ◽  
Healthy Men ◽  
Branched Chain

(1) Background: Whey protein lowers postprandial blood glucose in health and type 2 diabetes, by stimulating insulin and incretin hormone secretion and slowing gastric emptying. The branched-chain amino acids, leucine, isoleucine and valine, abundant in whey, may mediate the glucoregulatory effects of whey. We investigated the comparative effects of intragastric administration of leucine, isoleucine and valine on the plasma glucose, C-peptide and glucagon responses to and gastric emptying of a mixed-nutrient drink in healthy men. (2) Methods: 15 healthy men (27 ± 3 y) received, on four separate occasions, in double-blind, randomised fashion, either 10 g of leucine, 10 g of isoleucine, 10 g of valine or control, intragastrically, 30 min before a mixed-nutrient drink. Plasma glucose, C-peptide and glucagon concentrations were measured before, and for 2 h following, the drink. Gastric emptying of the drink was quantified using 13C-acetate breath-testing. (3) Results: Amino acids alone did not affect plasma glucose or C-peptide, while isoleucine and valine, but not leucine, stimulated glucagon (p < 0.05), compared with control. After the drink, isoleucine and leucine reduced peak plasma glucose compared with both control and valine (all p < 0.05). Neither amino acid affected early (t = 0–30 min) postprandial C-peptide or glucagon. While there was no effect on overall gastric emptying, plasma glucose at t = 30 min correlated with early gastric emptying (p < 0.05). (4) Conclusion: In healthy individuals, leucine and isoleucine lower postprandial blood glucose, at least in part by slowing gastric emptying, while valine does not appear to have an effect, possibly due to glucagon stimulation.

scholarly journals Effect of co-ingestion of amino acids with rice on glycaemic and insulinaemic response

2015 ◽  
Vol 114 (11) ◽  
pp. 1845-1851 ◽  
Author(s):  
Yean Yean Soong ◽  
Joseph Lim ◽  
Lijuan Sun ◽  
Christiani Jeyakumar Henry
Keyword(s):  
Amino Acids ◽  
Blood Glucose ◽  
Amino Acid ◽  
Glycaemic Index ◽  
Amino Acid Mixture ◽  
Postprandial Blood Glucose ◽  
Acid Mixture ◽  
White Rice ◽  
Amino Acid Mixtures

AbstractConsumption of high glycaemic index (GI) and glycaemic response (GR) food such as white rice has been implicated in the development of type 2 diabetes. Previous studies have reported the ability of individual amino acids to reduce GR of carbohydrate-rich foods. Because of the bitter flavour of amino acids, they have rarely been used to reduce GR. We now report the use of a palatable, preformed amino acid mixture in the form of essence of chicken. In all, sixteen healthy male Chinese were served 68 or 136 ml amino acid mixture together with rice, or 15 or 30 min before consumption of white rice. Postprandial blood glucose and plasma insulin concentrations were measured at fasting and every 15 min after consumption of the meal until 60 min after the consumption of the white rice. Subsequent blood samples were taken at 30-min intervals until 210 min. The co-ingestion of 68 ml of amino acid mixture with white rice produced the best results in reducing the peak blood glucose and GR of white rice without increasing the insulinaemic response. It is postulated that amino acid mixtures prime β-cell insulin secretion and peripheral tissue uptake of glucose. The use of ready-to-drink amino acid mixtures may be a useful strategy for lowering the high-GI rice diets consumed in Asia.

Short-term effects of milkshake containing polydextrose and maltodextrin on subjective feelings of appetite, energy intake and blood glucose in healthy females

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
İsmail Mücahit Alptekin ◽  
Ece Erdoğan ◽  
Aylin İşler ◽  
Esma Cansu Yanalak ◽  
Funda Pınar Çakiroğlu ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Energy Intake ◽  
Postprandial Blood Glucose ◽  
Dietary Fibers ◽  
Analog Scale ◽  
Short Term ◽  
Content Type ◽  
Ad Libitum ◽  
Desire To Eat ◽  
Healthy Females

Purpose Previous studies have reported that dietary fibers such as polydextrose and maltodextrin can reduce food intake; however, the studies on the differences of this effect are insufficient. The purpose of this paper is to compare the effects of dietary fibers maltodextrin and polydextrose on alterations of short-term satiety, energy intake and postprandial blood glucose in healthy females. Design/methodology/approach This study was designed as a randomized, crossover and double blind research. For this purpose, 21 healthy females consumed a milkshake containing 0 g (control), 15 g polydextrose (PDX) and 15 g maltodextrin (MDX), and an ad libitum lunch meal was served 150 min later. Subjective appetite scores (hunger, satiety, prospective food consumption and desire to eat) were measured using a visual analog scale. Appetite scores and blood glucose were measured before preload and once per 15 min after milkshake consumption. Findings Visual analog scale scores showed that PDX had an improved effect on satiety and hunger feelings. Compared to the control, dietary fiber increased the Area Under Curve (AUC) scores of satiety (p < 0.001) and decreased the AUC scores of hunger (p < 0.001), prospective food consumption (p < 0.001) and desire to eat (p < 0.001). Energy intake during ad libitum meal was significantly lower in PDX (Control: 862 (54.3) Kcal versus PDX: 679 (35.4) Kcal and MDX: 780 (49.3) Kcal. Moreover, the blood glucose levels were significantly lower in MDX. Originality/value This study conducted with healthy females demonstrated that PDX was more effective in inducing satiety during subsequent food intake, and that postprandial blood glucose were within more healthy levels in MDX.

scholarly journals Effects of metformin, acarbose, and sitagliptin monotherapy on gut microbiota in Zucker diabetic fatty rats

2019 ◽  
Vol 7 (1) ◽  
pp. e000717 ◽  
Author(s):  
Minchun Zhang ◽  
Rilu Feng ◽  
Mei Yang ◽  
Cheng Qian ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Gut Microbiota ◽  
Relative Abundance ◽  
16S Rrna Gene Sequencing ◽  
Postprandial Blood Glucose ◽  
Saline Control ◽  
Rrna Gene ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Zucker Diabetic Fatty Rats

ObjectiveRecent studies have demonstrated that gut microbiota was closely related to metabolic disorders such as type 2 diabetes. Oral antidiabetic medications including metformin, acarbose and sitagliptin lowered blood glucose levels via acting on the gastrointestinal tract. The aim of the study was to observe the comparisons among those medications on gut microbiota composition.Research design and methodsZucker diabetic fatty rats (n=32) were randomly divided into four groups, and had respectively gastric administration of normal saline (control), metformin (215.15 mg/kg/day), acarbose (32.27 mg/kg/day), or sitagliptin (10.76 mg/kg/day) for 4 weeks. Blood glucose levels were measured during an intragastric starch tolerance test after the treatments. 16S rRNA gene sequencing was used to access the microbiota in the fecal samples.ResultsMetformin, acarbose, and sitagliptin monotherapy effectively decreased fasting and postprandial blood glucose levels (p<0.001). Acarbose group displayed specific cluster and enterotype mainly composed byRuminococcus 2whileLactobacilluswas the dominant bacterium in the enterotype of the other three groups. The relative abundance of generaRuminococcus 2andBifidobacteriumwas dramatically higher in acarbose group. Metformin and sitagliptin increased the relative abundance of genus Lactobacillus. Metagenomic prediction showed that the functional profiles of carbohydrate metabolism were enriched in acarbose group.ConclusionsMetformin, acarbose and sitagliptin exerted different effects on the composition of gut microbiota and selectively increased the beneficial bacteria. Supplementation with specific probiotics may further improve the hypoglycemic effects of the antidiabetic drugs.

Load-dependent effects of duodenal glucose on glycemia, gastrointestinal hormones, antropyloroduodenal motility, and energy intake in healthy men

2007 ◽  
Vol 293 (3) ◽  
pp. E743-E753 ◽  
Author(s):  
Amelia N. Pilichiewicz ◽  
Reawika Chaikomin ◽  
Ixchel M. Brennan ◽  
Judith M. Wishart ◽  
Christopher K. Rayner ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Energy Intake ◽  
Healthy Subjects ◽  
Gastrointestinal Hormones ◽  
Saline Control ◽  
Gastrointestinal Hormone ◽  
Double Blind ◽  
Glucagon Like Peptide 1 ◽  
Glucose Plasma

Gastric emptying is a major determinant of glycemia, gastrointestinal hormone release, and appetite. We determined the effects of different intraduodenal glucose loads on glycemia, insulinemia, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and cholecystokinin (CCK), antropyloroduodenal motility, and energy intake in healthy subjects. Blood glucose, plasma hormone, and antropyloroduodenal motor responses to 120-min intraduodenal infusions of glucose at 1) 1 (“G1”), 2) 2 (“G2”), and 3) 4 (“G4”) kcal/min or of 4) saline (“control”) were measured in 10 healthy males in double-blind, randomized fashion. Immediately after each infusion, energy intake at a buffet meal was quantified. Blood glucose rose in response to all glucose infusions ( P < 0.05 vs. control), with the effect of G4 and G2 being greater than that of G1 ( P < 0.05) but with no difference between G2 and G4. The rises in insulin, GLP-1, GIP, and CCK were related to the glucose load ( r > 0.82, P < 0.05). All glucose infusions suppressed antral ( P < 0.05), but only G4 decreased duodenal, pressure waves ( P < 0.01), resulted in a sustained stimulation of basal pyloric pressure ( P < 0.01), and decreased energy intake ( P < 0.05). In conclusion, variations in duodenal glucose loads have differential effects on blood glucose, plasma insulin, GLP-1, GIP and CCK, antropyloroduodenal motility, and energy intake in healthy subjects. These observations have implications for strategies to minimize postprandial glycemic excursions in type 2 diabetes.

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