Effects of indigestible carbohydrates in barley on glucose metabolism, appetite and voluntary food intake over 16 h in healthy adults

Nutr J. 2013 Apr 11:12:46. doi: 10.1186/1475-2891-12-46.

Abstract

Background: Recent knowledge in animals suggests that gut microbial metabolism may affect host metabolism, including appetite regulating hormones. The aim of the present study was to evaluate the potential effects of a whole grain barley kernel product, rich in intrinsic indigestible carbohydrates (dietary fibre and resistant starch), on markers of metabolism and appetite regulation in healthy subjects.

Methods: Boiled barley kernels (BK) or white wheat bread (WWB; reference) were provided as late evening meals to 19 young adults in random order using a cross-over design. During subsequent ad libitum standardized breakfast and lunch meals (10.5-16 h), blood was collected for analysis of glucose, plasma insulin, adiponectin, ghrelin, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), serum free fatty acids (FFA) and interleukin (IL)-6. In addition, appetite sensations, voluntary energy intake and breath H2 were determined.

Results: BK as evening meal increased plasma GLP-1 at fasting (P < 0.05) and during the experimental day (P < 0.01) compared with WWB. In addition the BK evening meal decreased fasting serum FFA (P < 0.05) and tended to decrease fasting serum IL-6 (P = 0.06). At lunch, preceded by BK evening meal, voluntary energy intake was decreased (P < 0.05) when compared to WWB evening meal. The BK evening meal decreased incremental blood glucose area (P < 0.01), promoted higher breath H2 (P < 0.001), maintained adiponectin concentrations (P < 0.05) and reduced perceived hunger (P < 0.05) during 10.5-16 h after the meal.

Conclusions: The results indicate that the BK evening meal, facilitate glucose regulation, increase the release of GLP-1, reduce subsequent energy intake while at the same time decreasing hunger over 2 subsequent meals, and reduce fasting FFA the subsequent morning, possibly mediated through gut microbial fermentation of the indigestible carbohydrates.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Appetite*
  • Blood Glucose / metabolism*
  • Body Mass Index
  • Cross-Over Studies
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Fiber / administration & dosage
  • Energy Intake
  • Fatty Acids, Nonesterified / blood
  • Female
  • Gastrointestinal Tract / microbiology
  • Ghrelin / blood
  • Glucagon-Like Peptide 1 / blood
  • Hordeum / chemistry*
  • Humans
  • Hunger
  • Incretins / blood
  • Insulin / blood
  • Interleukin-6 / blood
  • Male
  • Meals
  • Metagenome
  • Nutritional Status
  • Postprandial Period*
  • Young Adult

Substances

  • Blood Glucose
  • Dietary Carbohydrates
  • Dietary Fiber
  • Fatty Acids, Nonesterified
  • Ghrelin
  • Incretins
  • Insulin
  • Interleukin-6
  • Glucagon-Like Peptide 1