Impact of Consumption of Beta-glucans on the Intestinal Microbiota and Glucose and Lipid Metabolism
Condition: Metabolic Syndrome; Dyslipidemia; Obesity, Abdominal; Hyperglycemia; Hypertension
MeSH terms: Hypertension; Metabolic Syndrome; Dyslipidemias; Hyperglycemia; Obesity, Abdominal; Syndrome
Study type: Interventional

Summary: 
      The purpose of this study is to investigate if daily consumption of barley beta-glucans
      effect lipid and glucose metabolism and alter intestinal microbiota composition in
      participants with metabolic syndrome or with high risk for metabolic syndrome development. It
      is assumed that 4-week intervention with beta-glucans will improve some clinical signs of
      metabolic syndrome and alter composition of intestinal microbiota. Variation in microbiota
      composition will be investigated with emphasis on Bacteroidetes and Firmicutes ratio.
      Furthermore it is presupposed that consumption of beta-glucans will stimulate growth of
      beneficial intestinal bacteria from genus Lactobacillus and Bifidobacteria and consequently
      effect production of short chain fatty acids in population with metabolic syndrome. Moreover
      it is presupposed that 4-week consumption of beta-glucans will have influence on glucose
      metabolism and will consequently improve insulin resistance within people with metabolic
      syndrome or high risk for metabolic syndrome development. It is assumed that 4-week
      consumption of beta-glucans will improve specific plasma lipid content in population with
      metabolic syndrome.
    

Detailed description: 
      In study it will be investigated whether daily consumption of barley beta-glucans integrated
      in bread product effects lipid and glucose metabolism and alter the composition of intestinal
      microbiota in a population with metabolic syndrome or with high risk for metabolic syndrome
      development. 70 participants with metabolic syndrome will be enrolled in study. Participants
      will daily consume 200 g of bread with high amount of beta-glucans.

      Hypothesis:

        1. 4- week consumption of beta-glucans alters composition of intestinal microbiota and
           changes ratio of bacteria from phylum Bacteroidetes and Firmicutes. Furthermore
           consumption of beta-glucans stimulates growth of beneficial intestinal bacteria from
           genus Lactobacillus and Bifidobacteria and consequently effects production of short
           chain fatty acids in population with metabolic syndrome.

        2. 4- week consumption of beta-glucans has influence on glucose metabolism and consequently
           improves insulin resistance within people with metabolic syndrome.

        3. 4 - week consumption of beta-glucans improves specific plasma lipid content in
           population with metabolic syndrome.

      Study will be designed as double blind, randomised, placebo controlled clinical trial and
      performed regarding to CONSORT 2010 recommendations for randomised clinical trials. Patient
      enrollment will be performed in several community health centres in Slovenia in association
      with family medicine doctors. Appropriate patients with metabolic syndrome or with high risk
      for metabolic development will be suggested to participate in clinical trial. Candidates will
      be suggested to participate in a two month study. If there will not be recruited enough
      participants for two month study they will be suggested for participation in one month study.
      Candidates interested in participating in study will be informed about study design and terms
      and conditions of study by main investigator.

      Study will be performed after successful recruitment of first 20 or more participants. Study
      will be performed three times, so that 70 participants will be recruited in complete study.
      Participants will consume bread with high beta-glucans content (around 3, 4 g beta-glucans
      per 100 g of bread) during 8 or 4 week period. Before beginning of study participants will
      have two week washout period without consuming any pre- and pro-biotics. They will remain
      their usual eating habits during study period except taking any antibiotics or pre- and
      pro-biotic. Participants will give blood and stool samples a day before intervention with
      barley beta-glucans. Blood sampling will involve oral glucose test for insulin resistance
      determination and sampling for specific lipid content determination. They will also have
      option to give a blood sample for genetic investigation of genes associated with lipid
      metabolism (apoE). Blood and stool sampling will be repeated day after intervention period.
      The same parameters as before intervention period except genetic analysis will be
      investigated. 72-hour dietary recall will be performed during intervention period
      individually to evaluate daily nutrient and energetic input of each participant.
    

Intervention name(s): Bread with added beta-glucans; Placebo Comparator: Bread without added beta-glucans
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Participants will daily consume bread with high content of beta-glucans. They will approximately consume 6 g beta-glucans per day in 200 g of bread. Intervention period will be 4 weeks. Meanwhile the participants will remain their usual eating habits except consuming any pro- or pre-biotics; Participants will daily consume placebo bread without any added beta-glucans (approximately 200 g per day). Intervention period will be 4 weeks. Meanwhile the participants will remain their usual eating habits except consuming any pro- or pre-biotics.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Metabolic syndrome; 4 -week intervention; Randomised placebo controlled parallel study; Beta-glucans; Abdominal fat; Dyslipidemia; Insulin resistance; Hypertension; Gut Microbiota Composition; Oral Glucose Tolerance Test; Lipid Profile; Real-Time Polymerase Chain Reaction; Denaturating Gradient Gel Electrophoresis