Diet Induced Intestinal Mucosal Adaptation

Study Overview
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Brief Summary
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Human beings are 'omnivores' meaning that all principal components of food (i.e. the macronutrients: carbohydrates, fat, proteins) can be assimilated by the gastrointestinal tract. When the gut mucosa is exposed to dietary changes it adjusts its functional behaviour. For example, a fatty diet demands certain digestive mechanisms, whereas others are needed to take care of a carbohydrate rich diet. Such dietary induced changes in appearance and functionality of the small intestinal mucosa have been described in animals but only little is known about it in man. The present project aims at elucidating in man if a 2 weeks diet dominated by either fat or carbohydrates, but with similar energy content, is associated with changes in the small intestinal mucosal appearance and metabolic signalling capacity.

Official Title
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Small Intestinal Adaptation to Isocaloric Diets Dominated Either by Fats or Carbohydrates

Conditions
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Healthy Conditions

Intervention / Treatment
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* Dietary Supplement: high fat diet (hfd)
* Dietary Supplement: high carb diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy volunteer not taking prescribed medications BMI ≤25 kg/m2 Exclusion Criteria: BMI ≥26 kg/m2 smoker previous or current gastrointestinal disease significant abdominal surgery pregnancy/breast feeding drug intolerance of importance (particularly opiates and midazolam used during endoscopy) history of drug addiction

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: high fat diet<br> | Dietary Supplement: high fat diet (hfd)<br>* Sixty % of the energy content is based on fat.<br>|
| Active Comparator: high carb diet<br> | Dietary Supplement: high carb diet<br>* Sixty % of the energy content is based on carbohydrates.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mucosal surface enlargement factor | The enlargement of the luminal surface area due to the villi structure is a morphometric factor defined as the total area of the mucosal surface in relation to the relatively flat area of the muscular is mucosae. | Appearance after 2 weeks of diet | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Epithelial electrical current in-vitro | Mucosal biopsies are mounted in min Ussing chambers. Ion-transporting capacity via SGLT-1 transported is reflected when switching from glucose-free to glucose-containing luminal solution, selectivity of transporter is confirmed by addition of phloridzin. | The condition after 2 weeks diet | 
| Mucosal electrical resistance in vitro | Mucosal biopsies are mounted in min Ussing chambers. Electrical resistance reflecting paracellular permeability is assessed when switching from glucose-free to glucose-containing luminal solution. | The condition after 2 weeks diet | 
| Glycemic control following a test meal | Blood concentrations of glucose and insulin are assessed over 2 hours following a mixed test meal. | The condition after 2 weeks diet | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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mucosa, intestinal, metabolic control, human, diet