Networks of Bacterium-Metabolite Interactions in the Small Intestine

Study Overview
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Brief Summary
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Probands with an Ileo- or Colostomy are assigned to consume a test meal which is either high in fat or high in carbohydrates. After the test meal samples from the stoma, urine, blood and skin are retrieved. These will be subjected to large scale analyses of microbiota and metabolite content. To get a better comparability test subjects will consume a standardized liquid diet three days before the study day.

Detailed Description
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Between both study days a two week wash out phase will be done. During the study day sampling will be done at set time points until 8 hours after the consumption of the test meal.

Official Title
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Networks of Bacterium-Metabolite Interactions in the Small Intestine

Conditions
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Diet, Healthy, Microbial Colonization

Intervention / Treatment
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* Other: Test meal (high fat = Nutricia Calogen®, or high carbohydrate = Nutricia preOp®)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Written informed consent General good health Ileostomy or colostomy Exclusion Criteria: Hematologic disorders with contraindication of blood draw Participation in other clinical trial interfering with study protocol

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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 test meal first, high carbohydrate test meal second<br>Consumption of a high fat challenge first, consumption of a high carbohydrate challenge after two weeks wash out | Other: Test meal (high fat = Nutricia Calogen®, or high carbohydrate = Nutricia preOp®)<br>* After a night fast participants will drink the test meal<br>|
| Experimental: High carbohydrate test meal first, high fat test meal second<br>Consumption of a high carbohydrate challenge first, consumption of a high fit challenge after two weeks wash out | Other: Test meal (high fat = Nutricia Calogen®, or high carbohydrate = Nutricia preOp®)<br>* After a night fast participants will drink the test meal<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Identification of stimulating and inhibiting metabolite and bacteria interactions | Correlation of results of secondary outcome measures to find interactions | 8 hours | 
| Reproduction of metabolite-bacteria interactions in vitro culture | By culturing of bacteria with possible interactions together in vitro | 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Analysis of bacteria species composition | by 16S rRNA sequencing of sample content | 8 hours | 
| Cultivation of bacterial strains in various conditions including ileal fluids | Cultivation of native species found in samples, as well as dedicated E. coli with recording capacity for transcriptional changes | 2 weeks | 
| Metabolite composition in intestinal fluids | by untargeted mass spectrometry | 8 hours | 
| Metabolite composition in blood | by untargeted mass spectrometry | 8 hours | 
| Metabolite composition in urine | by untargeted mass spectrometry | 8 hours | 
| Metabolite composition in intestinal fluids, blood and urine | by untargeted mass spectrometry | 8 hours | 
| Analyze eucaryotic and viral microbiome composition | by shotgun sequencing of sample content | 8 hours | 
| Analysis of microbiota metabolic potential | by shotgun sequencing of sample content | 8 hours | 
| Analysis of microbiota metabolic activity | by sequencing of transcriptome of sample content | 8 hours | 
| Analysis of microbiota biomass | by measuring absolute bacteria counts by flow cytometry of 16S spiking | 8 hours |