Abstract
BACKGROUND: Genetically modified (GMO) high-amylose barley lowers postprandial glucose. Since certain EU countries do not allow GMO barley, we therefore assessed if high-amylose barley made from traditional breeding (Lean Baking Barley, LBB) lowers postprandial glucose compared to bread made from regular barley (RB) or wheat (WF) in individuals with or without type 2 diabetes (T2D). METHODS: In a randomised crossover design, 38 participants (18 T2D and 20 non-T2D) consumed 160 g of bread made from 100% LBB, RB, or WF. Postprandial metabolic responses, appetite and bread perception were measured. A mixed model ANOVA was used for analysis. RESULTS: LBB bread reduced 4 h postprandial glucose measured as incremental area under the curve (iAUC) by 41% and 39% vs. WF and RB bread in T2D and by 28% and 32% in non-T2D (all, P < 0.05). In T2D, LBB reduced postprandial insulin (iAUC) by 52% and 38% vs. WF and RB, and by 60% vs. WF in non-T2D (all, P < 0.05). Postprandial GIP (iAUC) was lower after LBB in both groups vs. RB and WF (P < 0.05). GLP-1 (iAUC) and FFA (tAUC) were lower after LBB vs. WF in non-T2D (P < 0.05), but not in T2D. Appetite scores were similar for all breads. Overall liking was higher for WF but did not differ between barley types. CONCLUSION: LBB breads reduce postprandial glucose and insulin compared to RB and WF bread in individuals irrespective of T2D. LBB may have potential as a functional food in prevention and management of T2D. ClinicalTrails.gov registration: NCT04702672.