Dietary Fiber and Gut Microbiome Study
Condition: Healthy
Study type: Interventional

Summary: 
      The purpose of this dietary intervention is to study the effects of several dietary fibers on
      the gut microbiota at the personal level. Hypothesis 1: Intake of specific dietary fibers
      improves the blood lipid profile depending on the personal microbiota of the participants.

      Hypothesis 2: detailed food intake analysis and continuous monitoring of gut microbiota
      enables to draw causative interrelationships between food components, bacteria of gut
      microbiome and health characteristics.
    

Detailed description: 
      The study design is a cross-over, pre-post intervention trial. All participants are enrolled
      into all study periods. Study consists of baseline period, four periods of dietary fiber
      intervention and four periods of wash-outs.

      The main goal of this study was to elucidate the patterns between individual dietary fibers
      and gut microbiota at the personal level. Each person has a unique (individual) intestinal
      microbiological profile that changes according to lifestyle (diet, environment, physical
      activity), age and health status. With next generation sequencing methods to map microbial
      communities and detailed nutritional analysis including blood tests, it is possible to
      identify the specific effects of specific fiber on a selected (individual) microbiota. TFTAK
      researchers have long-term experience in microbiota analysis as well as diet design and
      nutrition analysis, which can be successfully applied in this project.

      PRELIMINARY STUDY EVALUATION AND TESTING

        1. Complete preliminary study questionnaire

        2. Complete orientation to the study and provide voluntary consent to join the study

        3. Collection of coded intervention products, sampling supplies, and instructional
           materials

      1-WEEK QUESTIONNAIRE AND LABORATORY VISIT

      1. Record food intake and gastrointestinal function for 7 days 2. Collect health data and
      provide a 7-day food diary using web-based program Nutridata (tap.nutridata.ee) 3. Provide a
      stool and blood sample at the laboratory 3-WEEK QUESTIONNAIRE AND

      LABORATORY VISITS

        1. Record food intake and gastrointestinal symptoms for 7 days

        2. Collect health data and provide a 3-day food frequency questionnaire

        3. Provide a stool and blood sample at the laboratory BLOOD SAMPLE

      ANALYSES

      1. Provide the blood sample at the laboratory in the morning in an overnight fasted state.

      DIETARY INTERVENTION

      Study consists of baseline period, four periods of dietary fiber intervention and four
      periods of wash-outs:

        1. Baseline mapping (health questionnaire, 1 week food diary before sampling of blood and
           gut microbiota)

        2. Dietary fiber 1, 3 weeks, analyses: health questionnaire, 1 week food diary before
           sampling of blood and gut microbiota

        3. Wash-out period, 2 weeks, analyses: health questionnaire, 1 week food diary before
           sampling of blood and gut microbiota

        4. Repeating 3 times periods of 2 and 3. In each dietary fiber period 15 g/day of oat
           fiber, rye fiber, mix I and mix II of dietary fibers are used as test compounds. Dietary
           fiber mix I and mix II are inulin, beta-glucan, polydextrose, citrus pectin and
           psyllium, and beta-glucan, citrus pectin and psyllium, respectively.
    

Intervention name(s): Dietary fiber 1; Dietary fiber 2; Dietary fiber 3; Dietary fiber 4
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): Description in the arm description; Description in the arm description; Description in the arm description; Description in the arm description
Allocation: Non-Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: Gut microbiome; food diary; dietary fibers