Effect of Amino Acids and Sugar Alcohols on Gastric Emptying and Release of Satiation Peptides in Humans

Study Overview
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Brief Summary
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With this study the investigators investigate the effects of amino acids (tryptophan in two different concentrations, leucin) and sugar alcohols (xylitol, erythritol) on satiety mechanisms.

Official Title
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Effect of Amino Acids and Sugar Alcohols on Gastric Emptying and Release of Satiation Peptides in Normal Weight and Obese Subjects

Conditions
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Endocrine System Diseases

Intervention / Treatment
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* Dietary Supplement: 0.52 g L-Tryptophan
* Dietary Supplement: 1.56 g L-Tryptophan
* Dietary Supplement: 1.56 g L-Leucine
* Dietary Supplement: 50 g Xylitol
* Dietary Supplement: 75 g Erythritol
* Dietary Supplement: 75 g Glucose
* Dietary Supplement: 300 mL tap water
* Other: 50 mg 13C-sodium acetate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy normal weight subjects with a body-mass index of 19.0-24.9 Healthy obese subjects with a body-mass index of > 30 Normal eating habits (no diets; no dietary changes; no special dietary habits, such as vegetarian/vegan) Age 18-40 years Stable body weight for at least three months Exclusion Criteria: Smoking Substance abuse Regular intake of medications (except for oral contraceptives) Medical or psychiatric illness History of gastrointestinal disorders Food allergies Pregnancy, breast feeding

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 0.52 g L-Tryptophan<br>0.52 g L-Tryptophan in 300 mL tap water (plus 50 mg 13C-sodium acetate) given via nasogastric tube | Dietary Supplement: 0.52 g L-Tryptophan<br> <br> Other: 50 mg 13C-sodium acetate<br> <br> |
| Active Comparator: 1.56 g L-Tryptophan<br>1.56 g L-Tryptophan in 300 mL tap water (plus 50 mg 13C-sodium acetate) given via nasogastric tube | Dietary Supplement: 1.56 g L-Tryptophan<br> <br> Other: 50 mg 13C-sodium acetate<br> <br> |
| Active Comparator: 1.56 g L-Leucine<br>1.56 g L-Leucine in 300 mL tap water (plus 50 mg 13C-sodium acetate) given via nasogastric tube | Dietary Supplement: 1.56 g L-Leucine<br> <br> Other: 50 mg 13C-sodium acetate<br> <br> |
| Active Comparator: 50 g Xylitol<br>50 g Xylitol in 300 mL tap water (plus 50 mg 13C-sodium acetate) given via nasogastric tube | Dietary Supplement: 50 g Xylitol<br> <br> Other: 50 mg 13C-sodium acetate<br> <br> |
| Active Comparator: 75 g Erythritol<br>75 g Erythritol in 300 mL tap water (plus 50 mg 13C-sodium acetate) given via nasogastric tube | Dietary Supplement: 75 g Erythritol<br> <br> Other: 50 mg 13C-sodium acetate<br> <br> |
| Placebo Comparator: 75 g Glucose<br>75 g Glucose in 300 mL tap water (plus 50 mg 13C-sodium acetate) given via nasogastric tube | Dietary Supplement: 75 g Glucose<br> <br> Other: 50 mg 13C-sodium acetate<br> <br> |
| Placebo Comparator: Tap water<br>300 mL tap water (plus 50 mg 13C-sodium acetate) given via nasogastric tube | Dietary Supplement: 300 mL tap water<br> <br> Other: 50 mg 13C-sodium acetate<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of different aminoacids and sugar alcohols on secretion of satiation hormones | Plasma concentrations of glucose | changes from baseline to three hours after treatment | 
| Effect of different aminoacids and sugar alcohols on secretion of satiation hormones | Plasma concentrations of insulin are measured | changes from baseline to three hours after treatment | 
| Effect of different aminoacids and sugar alcohols on secretion of satiation hormones | Plasma concentrations of glucagon are measured | changes from baseline to three hours after treatment | 
| Effect of different aminoacids and sugar alcohols on secretion of satiation hormones | Plasma concentrations of glucagon-like Peptide (GLP-1) are measured | changes from baseline to three hours after treatment | 
| Effect of different aminoacids and sugar alcohols on secretion of satiation hormones | Plasma concentrations of PYY are measured | changes from baseline to three hours after treatment | 
| Effect of different aminoacids and sugar alcohols on secretion of satiation hormones | Plasma concentrations of cholecystokinin are measured | changes from baseline to three hours after treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of different aminoacids and sugar alcohols on gastric emptying | measured by C13 breath test | changes from baseline to four hours after treatment |