Metabolic Signatures of Dairy Products Ingestion in Humans: Effect of Age

Study Overview
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Brief Summary
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Despite the fact that dairy products are greatly consumed, it remains today very difficult to determine with a classical blood biochemical test whether a person has ingested a fresh fermented dairy product or just milk, while their biological, metabolic and health impacts may be different. The metabolic footprint left by the consumption of these products could be modified by the age of the consumer. Indeed, in the elderly, the processes of digestion, assimilation and metabolism are known to be altered /different compared to healthy adults. Thus, different metabolic signatures in the elderly could appear as the result of a less effective use and metabolism of the nutrients ingested. This could further also result in different or altered biological effects on dairy products.

Detailed Description
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The two main objectives of this project are to: Determine precisely the plasma and urine metabolic signatures resulting from acute (postprandial) ingestion of yogurt or milk. Characterize the metabolic signature following the consumption of these dairy products in the elderly and compared with the signature of reference (adult). Understand the mechanisms and metabolic pathways involved if discriminating metabolites between age are detected.. The clinical study is open, monocentric, controlled and randomized, in a cross experimental design. The study is not performed in a double blind way. However, the measure bias will be limited because of the standardized and objective characteristic of the main criteria. Moreover, biological samples will be analyzed by the same partners of the project. Each subject will be its own control, so that confusion factors related to individual variability will be eliminated. A total of 28 volunteers (men) will participate in the study: 14 adults and 14 old people (>65 yrs-old). After 3 weeks of controlled diet (without consumption of dairy products) the volunteers will ingest 600g of milk or yogurt. After 1 week of wash-out, the other product will be consumed. Blood and urine will be collected during the postprandial period. The monocentric characteristic of the study, the low number of subjects and the expertise of the involved staff will enable to limit the number of missing data. The randomization (latin square) has been established by a bio-statistician of the project before the study started. A document describing the randomization proceeding is confidentially kept.

Official Title
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Metabolic Signatures Resulting From Acute (Postprandial) Ingestion of Yoghurt or Milk in Humans: Effect of Age

Conditions
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Nutrition

Intervention / Treatment
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* Other: Acute milk intake
* Other: Acute Yogurt intake


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: no pathology and no medical treatment BMI >=21 and <=30 kg/m² normal biological status no dislike for diary intake Exclusion Criteria: smoking no pathology and no medical treatment (no antibiotics in the last 3 months) consumption of nutritional supplements several times at week

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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Male

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: Milk acute intake<br>14 adult and 14 elderly volunteers will consume 600mL of milk. Blood (11 sampling points) and urine samples (3 collection points) will be collected before the ingestion and during the postprandial period (6h). | Other: Acute milk intake<br>* Food matrix: milk<br>|
| Experimental: Yogurt acute intake<br>14 adult and 14 elderly volunteers will consume 600mL of yogurt. Blood (11 sampling points) and urine samples (3 collection points) will be collected before the ingestion and during the postprandial period (6h). | Other: Acute Yogurt intake<br>* Food matrix: yogurt<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Metabolomics: discovery of novel biomarkers of acute dairy intake (milk and yogurt) | Analysis of the urine and plasma metabolome | Baseline, then ten times during the 6h following product intake on two different days (one milk, one yogurt) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| glucose homeostasis markers | Analysis of blood glucose and insulin levels | Baseline, then ten times during the 6h following product intake on two different days (one milk, one yogurt) | 
| lipid homeostasis markers | Analysis of blood cholesterol and triglycerides levels | Baseline, then ten times during the 6h following product intake on two different days (one milk, one yogurt) | 
| Inflammation markers | IL-6, TNF-alpha blood levels | Baseline, then ten times during the 6h following product intake on two different days (one milk, one yogurt) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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metabolomics, dairy products, milk, yogurt, elderly