Title: Differentiating the effects of whey protein and guar gum preloads on postprandial glycemia in type 2 diabetes

• Published in: Clinical nutrition (Edinburgh, Scotland) Scotland), 2019-12, Vol.38 (6), p.2827-2832
• Main Authors: Watson, Linda E., Phillips, Liza K., Wu, Tongzhi, Bound, Michelle J., Checklin, Helen, Grivell, Jacqueline, Jones, Karen L., Horowitz, Michael, Rayner, Christopher K.
• Format: Article
• Language: English
• Subjects: Gastric emptying; Guar gum; Incretin hormones; Postprandial glycemia; Type 2 diabetes; Whey protein
• ISSN: 0261-5614; 1532-1983
• DOI: 10.1016/j.clnu.2018.12.014

Whey protein and guar gum have both been reported to reduce postprandial glycemia in health and type 2 diabetes, associated with stimulation of glucagon-like peptide-1 (GLP-1) and/or slowing of gastric emptying. Our aim was to evaluate, in type 2 diabetes, the acute effects of low dose “preloads” of whey and guar, given alone or in combination before a meal, on postprandial glycemia, insulin, GLP-1, and gastric emptying. 21 patients with type 2 diabetes, managed by diet or metformin alone, were each studied on 4 days. They received a preload “shake” 15min before a mashed potato meal (368.5 kcal) labeled with 13C-octanoic-acid. The preloads comprised either (i) 17 g whey (W), (ii) 5 g guar (G), (iii) 17 g whey + 5 g guar (WG) each sweetened with 60 mg sucralose, and (iv) 60 mg sucralose alone (control; C), all dissolved in 150 mL water. Venous blood was sampled frequently for measurements of glucose, insulin, and GLP-1 concentrations. Gastric half-emptying time (T50) was calculated from breath 13CO2 excretion over 240 min. Postprandial blood glucose concentrations were lower with W and WG compared to C (each P