Metabolic Signatures of Dairy Products Ingestion in Humans: Effect of Age
Condition: Nutrition
Study type: Interventional

Summary: 
      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: 
      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.
    

Intervention name(s): Acute milk intake; Acute Yogurt intake
Intervention type(s): Other; Other
Intervention description(s): Food matrix: milk; Food matrix: yogurt
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: dairy products; milk; yogurt; metabolomics; elderly