Taste Physiology in Obese Volunteers Before and After Bariatric Surgery

Study Overview
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Brief Summary
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The objective is to investigate neuro-anatomical correlates of gastrointestinal taste stimulation by means of functional MRI before and after bariatric surgery. Intragastric administration of glucose, monosodium glutamate, chloroquine and placebo is followed by functional brain MRI in obese humans before and 3 months after surgery.

Official Title
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Taste Physiology in Obese Volunteers Before and After Bariatric Surgery

Conditions
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Obesity

Intervention / Treatment
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* Dietary Supplement: Placebo
* Dietary Supplement: Glucose
* Dietary Supplement: Monosodium glutamate
* Dietary Supplement: Quinine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: morbidly obese patients (BMI min 35kg/m2) scheduled for bariatric surgery right handed Exclusion Criteria: cardiovascular disease neurologic/psychiatric disorders

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo preoperative<br>Single intragastric instillation of 200ml tap water via nasogastric tube | Dietary Supplement: Placebo<br>* Tap water 200ml<br>|
| Placebo Comparator: Placebo postoperative<br>Single intragastric instillation of 200ml tap water via nasogastric tube | Dietary Supplement: Placebo<br>* Tap water 200ml<br>|
| Active Comparator: Glucose preoperative<br>Single intragastric instillation of 200ml tap water with 25g glucose via nasogastric tube | Dietary Supplement: Glucose<br>* 25g Glucose in 200ml tap water<br>|
| Active Comparator: Glucose postoperative<br>Single intragastric instillation of 200ml tap water with 25g glucose via nasogastric tube | Dietary Supplement: Glucose<br>* 25g Glucose in 200ml tap water<br>|
| Active Comparator: Monosodium glutamate preoperative<br>Single intragastric instillation of 200ml tap water with 1g monosodium glutamate via nasogastric tube | Dietary Supplement: Monosodium glutamate<br>* 1g monosodium glutamate in 200ml tap water<br>|
| Active Comparator: Monosodium glutamate postoperative<br>Single intragastric instillation of 200ml tap water with 1g monosodium glutamate via nasogastric tube | Dietary Supplement: Monosodium glutamate<br>* 1g monosodium glutamate in 200ml tap water<br>|
| Active Comparator: Quinine preoperative<br>Single intragastric instillation of 200ml tap water with 17mg quinine via nasogastric tube | Dietary Supplement: Quinine<br>* 17mg quinine in 200ml tap water<br>|
| Active Comparator: Quinine postoperative<br>Single intragastric instillation of 200ml tap water with 17mg quinine via nasogastric tube | Dietary Supplement: Quinine<br>* 17mg quinine in 200ml tap water<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of tastants on cerebral blood flow measured by functional brain MRI |  | changes from baseline to one hour after treatment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of tastants plasma glucagon-like peptide (GLP-1) concentrations |  | changes from baseline to one hour after treatment | 
| Effect of tastants plasma ghrelin concentrations |  | changes from baseline to one hour after treatment |