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

Abstract

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 70 years, 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.

Exercise and Beta-Glucan Consumption (Saccharomyces cerevisiae) Improve the Metabolic Profile and Reduce the Atherogenic Index in Type 2 Diabetic Rats (HFD/STZ)

“…Among the possible beta-glucan’s action, we can highlight the stimulation of intestinal motility, as well as changes in the microbiota and modulation of hormones secretion in the intestine [27,40,41]. Intestinal motility can be stimulated by the increase in the viscosity of the digesta in the lumen, due to the formation of a gelatinous layer [42,43].…”

“…High molecular weight beta-glucans (1,3/1,6) can also serve as a substrate for symbiotic microorganisms present in the intestine, increasing IgA and lysozyme secretion, and, as a consequence, immune resistance [40]. Another mechanism related to the functional effect of beta-glucans is satiety, mediated by gastrointestinal hormones [41]. Beta-glucans modulate the secretion of ghrelin and peptide YY, in order to inhibit hunger, acting indirectly in glycemic and lipidemic control [44].…”

Blueberries’ Impact on Insulin Resistance and Glucose Intolerance

“…In overweight and obese subjects, Rebello et al [24] used a gastrointestinal microbiome modulator (GIMM) containing inulin from agave, β-glucan from oats, and polyphenols from blueberry pomace as the dietary intervention. Consuming GIMM over 4 weeks improved glucose tolerance (assessed by oral glucose tolerance test; OGTT), but no changes in insulin resistance (assessed by HOMA-IR) were observed.…”

“…Insulin resistance and/or glucose tolerance were assessed using HOMA-IR (homeostatic model assessment-estimated insulin resistance), FSIVGTT (Frequently sampled intravenous glucose tolerance test), and OGTT (oral glucose tolerance test). Rebello et al [24], used HOMA-IR and OGTT and Stull et al [25,31], used the clamp and FSIVGTT. * Studies that used bilberries.…”

“…The scientific evidence supporting the anti-diabetic health benefits of blueberries is growing. Pre-clinical [14,15,16,17,18,19,20,21] and clinical [22,23,24,25] studies have found improvements in insulin resistance and glucose tolerance after blueberry consumption in obese and insulin-resistant rodents and humans. For many years, increased consumption of blueberries has been a folk remedy in Canada for treating T2DM [26].…”