Effect of mulberry fruit extract on glucose fluxes after a wheat porridge meal:a dual isotope study in healthy human subjects

Background: Previous research has shown the efficacy of mulberry extracts for lowering post-prandial glucose (PPG) responses. The postulated mechanism is slowing of glucose absorption, but effects on glucose disposal or endogenous production are also possible. This research assessed the effect of a specified mulberry fruit extract (MFE) on these three glucose flux parameters. Methods: The study used a double-blind, randomized, controlled, full cross-over design. In 3 counter-balanced treatments, 12 healthy adult male subjects, mean (SD) age 24.9 (2.50) years and body mass index 22.5 (1.57) kg/m2, consumed porridge prepared from 13C-labelled wheat, with or without addition of 0.75 g MFE, or a solution of 13C-glucose in water. A co-administered 2H-glucose venous infusion allowed for assessment of glucose disposal. Glucose flux parameters, cumulative absorption (time to 50% absorption, T50%abs), and PPG positive incremental area under the curve from 0 to 120 min (+iAUC0–120) were determined from total and isotopically labelled glucose in plasma. As this exploratory study was not powered for formal inferential statistical tests, results are reported as the mean percent difference (or minutes for T50%abs) between treatments with 95% CI. Results: MFE increased mean T50%abs by 10.2 min, (95% CI 3.9–16.5 min), and reduced mean 2 h post-meal rate of glucose appearance by 8.4% (95% CI −14.9 to −1.4%) and PPG + iAUC0-120 by 11% (95% CI −26.3 to −7.3%), with no significant changes in glucose disposal or endogenous production. Conclusions: The PPG-lowering effect of MFE is primarily mediated by a reduced rate of glucose uptake.</p

Effect of fibre additions to flatbread flour mixes on glucose kinetics:A randomised controlled trial

We previously found that guar gum (GG) and chickpea flour (CPF) added to flatbread wheat flour lowered postprandial blood glucose (PPG) and insulin responses dose dependently. However, rates of glucose influx cannot be determined from PPG, which integrates rates of influx, tissue disposal and hepatic glucose production. The objective was to quantify rates of glucose influx and related fluxes as contributors to changes in PPG with GG and CPF additions to wheat-based flatbreads. In a randomised cross-over design, twelve healthy males consumed each of three different C-13-enriched meals: control flatbreads (C), or C incorporating 15 % CPF with either 2 % (GG2) or 4 % (GG4) GG. A dual isotope technique was used to determine the time to reach 50 % absorption of exogenous glucose (T-50 %abs, primary objective), rate of appearance of exogenous glucose (RaE), rate of appearance of total glucose (RaT), endogenous glucose production (EGP) and rate of disappearance of total glucose (RdT). Additional exploratory outcomes included PPG, insulin, glucose-dependent insulinotropic peptide and glucagon-like peptide 1, which were additionally measured over 4 h. Compared with C, GG2 and GG4 had no significant effect on T-50 %abs. However, GG4 significantly reduced 4-h AUC values for RaE, RaT, RdT and EGP, by 11, 14, 14 and 64 %, respectively, whereas GG2 showed minor effects. Effect sizes over 2 and 4 h were similar except for significantly greater reduction in EGP for GG4 at 2 h. In conclusion, a soluble fibre mix added to flatbreads only slightly reduced rates of glucose influx, but more substantially affected rates of postprandial disposal and hepatic glucose production

Effect of mulberry fruit extract on glucose fluxes after a wheat porridge meal:a dual isotope study in healthy human subjects

Background: Previous research has shown the efficacy of mulberry extracts for lowering post-prandial glucose (PPG) responses. The postulated mechanism is slowing of glucose absorption, but effects on glucose disposal or endogenous production are also possible. This research assessed the effect of a specified mulberry fruit extract (MFE) on these three glucose flux parameters. Methods: The study used a double-blind, randomized, controlled, full cross-over design. In 3 counter-balanced treatments, 12 healthy adult male subjects, mean (SD) age 24.9 (2.50) years and body mass index 22.5 (1.57) kg/m2, consumed porridge prepared from 13C-labelled wheat, with or without addition of 0.75 g MFE, or a solution of 13C-glucose in water. A co-administered 2H-glucose venous infusion allowed for assessment of glucose disposal. Glucose flux parameters, cumulative absorption (time to 50% absorption, T50%abs), and PPG positive incremental area under the curve from 0 to 120 min (+iAUC0–120) were determined from total and isotopically labelled glucose in plasma. As this exploratory study was not powered for formal inferential statistical tests, results are reported as the mean percent difference (or minutes for T50%abs) between treatments with 95% CI. Results: MFE increased mean T50%abs by 10.2 min, (95% CI 3.9–16.5 min), and reduced mean 2 h post-meal rate of glucose appearance by 8.4% (95% CI −14.9 to −1.4%) and PPG + iAUC0-120 by 11% (95% CI −26.3 to −7.3%), with no significant changes in glucose disposal or endogenous production. Conclusions: The PPG-lowering effect of MFE is primarily mediated by a reduced rate of glucose uptake.</p