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

Abstract

BackgroundRecent 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.MethodsBoiled 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.ResultsBK 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.ConclusionsThe 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.

Nutritional Impacts of Different Whole Grain Milling Techniques: A Review of Milling Practices and Existing Data

“…Intervention studies often have small numbers of subjects and show the benefits of ingestion of a specific whole grain, such as oats or rye, but not necessarily a mixture of whole grains or brown rice (37)(38)(39)(40). Even large randomized intervention trials (41), such as one with healthy overweight subjects in the United Kingdom, have not shown improvements in markers of heart disease with increased intake of whole grain foods compared with usual intake.…”

Inclusion of Konjac Flour in the Gestation Diet Changes the Gut Microbiota, Alleviates Oxidative Stress, and Improves Insulin Sensitivity in Sows

“…Dietary interventions are thus a potential tool to modulate gut microbiota and further impact host health (18,19). Previous studies have shown that resistant starch (rich in nonstarch polysaccharides) improved glucose tolerance in healthy subjects with a normal body mass index (20,21) and provided evidence of a link between colonic fermentation and glucose metabolism (20). However, to date, little information is available about the impact of KF feed consumption on the gut microbiota of pregnant females and the correlation between gut microbiota and metabolic parameters after dietary KF supplementation.…”

The Therapeutic Potential of Resistant Starch in Modulation of Insulin Resistance, Endotoxemia, Oxidative Stress and Antioxidant Biomarkers in Women with Type 2 Diabetes: A Randomized Controlled Clinical Trial

“…However, other studies have informed researchers about the mechanisms underlying the effects of RS on oxidative stress. Some proposed mechanisms for prebiotics antioxidant effects include the scavenging ability of reactive oxygen species (ROS) [32] , SCFAs [33] , reduction of inflammation and endotoxin [34] , a change in microflora toward Lactobacilli which contain antioxidants [35] , suppression of CD11c expression in adipose tissue [36] and reduction of the levels of FFAs [37] .…”