Gastrointestinal microbiome modulator improves glucose tolerance in overweight and obese subjects: A randomized controlled pilot trial

J Diabetes Complications. Nov-Dec 2015;29(8):1272-6. doi: 10.1016/j.jdiacomp.2015.08.023. Epub 2015 Sep 3.


Objective: The objective of this study was to examine the effects of a gastrointestinal microbiome modulator (GIMM) containing inulin, β-glucan, blueberry anthocyanins, and blueberry polyphenols on metabolic parameters, fecal markers of gut microbiota, and satiety.

Design and methods: Thirty overweight or obese individuals aged 18 to 70years, were enrolled in a randomized controlled trial. Participants consumed the test product or placebo daily for four weeks. Stool samples were collected and blood was drawn at baseline and week four for assessments of gut microbiota, satiety hormones, glucose control, and lipid measures. Subjective satiety was assessed weekly. Linear models were used to compare differences from baseline to week four.

Results: GIMM consumption improved blood glucose tolerance (p=0.008), and increased satiety (p=0.03). There were no statistically significant differences in insulin sensitivity, fecal markers of gut microbiota, plasma satiety hormones, or serum lipid concentrations between the groups. However, plasma satiety hormones and fecal short chain fatty acid concentrations increased in the test group compared to the placebo.

Conclusions: GIMM consumption for four weeks, increases satiety, and improves glucose tolerance possibly through insulin-independent pathways.

Keywords: Blueberry; Glucose tolerance; Inulin; Microbiota; Satiety; β-Glucan.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Appetite Depressants / therapeutic use*
  • Avena / chemistry
  • Biomarkers / analysis
  • Blueberry Plants / chemistry
  • Body Mass Index
  • Dietary Fiber / therapeutic use*
  • Dietary Supplements*
  • Feces / chemistry
  • Feces / microbiology
  • Female
  • Flavonoids / therapeutic use*
  • Fruit / chemistry
  • Gastrointestinal Microbiome*
  • Glucose Intolerance / prevention & control*
  • Humans
  • Insulin Resistance
  • Inulin / administration & dosage
  • Male
  • Middle Aged
  • Obesity / blood
  • Obesity / diet therapy
  • Obesity / metabolism
  • Obesity / microbiology
  • Overweight / blood
  • Overweight / diet therapy*
  • Overweight / metabolism
  • Overweight / microbiology
  • Pilot Projects
  • Satiety Response
  • Seeds / chemistry
  • beta-Glucans / administration & dosage


  • Appetite Depressants
  • Biomarkers
  • Dietary Fiber
  • Flavonoids
  • beta-Glucans
  • Inulin