Effect of a Kefir Beverage on Immunity and Lipid Profile
Condition: Prebiotics
Study type: Interventional

Summary: 
      This is an exploratory cluster randomized controlled trial to evaluate the effect of a kefir
      beverage, enriched with prebiotics components, on immunity, lipid profile and adiposity in a
      population-based study, using the family as the intervention unit.
    

Detailed description: 
      The gastrointestinal tract is populated by a collection of microorganisms, primarily
      bacteria, that interact with intestinal host cells. In the past two decades, several studies
      have demonstrated the effects of the intestinal microbiota on host physiological, metabolic
      and immunological processes and have revealed that the microbiota is fundamental to host body
      function. There is currently a growing interest in manipulating the intestinal microbiota to
      enhance the effects on health and welfare of the intestine. In this regard, since its
      introduction, the concept of prebiotics has stimulated both scientific and industrial
      interest. A dietary prebiotic is a selectively fermented ingredient that results in specific
      changes, in the composition and/or activity of the gastrointestinal microbiota, thus
      conferring benefits upon host health. To date, the prebiotics most widely evaluated in human
      clinical trials are inulin-type fructans (inulin, fructo-oligosaccharides, oligofructose) and
      galacto-oligosaccharides (GOS).

      The investigators goal is to conduct a human clinical trial to evaluate the impacts of a
      functional-prebiotic beverage on immunity and metabolic profile.

      This study will be performed on a family-oriented basis. 44 families/clusters (~ 150 children
      and adults, older than 3 years) will be selected to participate in the study and will be
      randomized into intervention group (n=22 families) and control (n=22 families) groups.

      Weight, body mass index (BMI), waist circumference (WC), nutrient intake from food frequency
      questionnaire, physical activity, blood pressure, allergic sensitization, metabolic function
      (fasting blood glucose, HbA1c, insulin resistance and lipid profile), general lymphocyte
      overview (B-cells, T-cells and NK-cells) and sub-populations of T-helper cells (Th1, Th2,
      Th17 and T-regulatory), inflammation markers (C-reactive protein, interleukin-6 and tumor
      necrosis factor-alpha) will be measured at baseline and after 4 months.

      Mixed effect models analysis will be performed to assess changes in the cardiometabolic and
      immune parameters.
    

Intervention name(s): Prebiotic group; Placebo group
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Fermented dairy product with galacto-oligosaccharides (GOS), kefiran and other metabolites resulting from the fermentation with kefir granules.; Beverage with color, flavor and nutritional composition similar to the fermented dairy product but not containing the prebiotic components.
Other intervention name(s): Fermented dairy product with kefir granules; Dairy product without prebiotic components
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Cluster randomized controlled trial
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Prebiotics; kefir