Proceedings of the Nutrition Society | 2021
Mycoprotein reduces endogenous glucose production when consumed with a mixed-meal tolerance test
Abstract
Postprandial glucose kinetics can be managed by altering dietary composition. The addition of soluble fibre to a meal can decrease the total rate of glucose appearance (RaT), while insoluble fibre has been shown to increase the rate of glucose disappearance (RdT). Mycoprotein (MYC) is a high-fibre food (1/3 soluble and 2/3 insoluble) shown to reduce postprandial glucose and insulin concentrations in healthy participants, though the underlying glucose kinetics have not been explored. The present study took a dual stable isotope tracer approach to determine how MYC impacts glucose kinetics when ingested with a mixed-meal. We hypothesised that the previously observed reduction in glucose concentrations with MYC ingestion would be due to a lower RaT. This study also aimed to determine whether this effect was dose dependent. In a double-blind, randomised, cross-over design, 12 healthy adults (M:F 6:6) attended 3 experimental test days, involving ingestion of a test drink, enriched with 100mg [U-13C] glucose, containing 250ml whole milk, 50 g glucose, and either 0 (CON), 20 (MYC20), or 40 g (MYC40) MYC. CON and MYC20 were matched for energy, protein (18 g), carbohydrate (75 g) and fat (12 g). An intravenous infusion of D-[6,6-2H2] glucose was used to determine glucose kinetics over 6 h. Time-course and AUCs of glucose, insulin, and rate of appearance of total (RaT), exogenous (RaEx), endogenous (EGP), and RdT, of glucose were assessed using twoand one-way ANOVAs, respectively. Drink ingestion resulted in a rapid increase in blood glucose and serum insulin concentrations, peaking at 45 and 30min, respectively; however there were no differences between the conditions (P> 0.05). Both RaT and RdT decreased in the MYC40 compared with CON during 0–120min (-14 ± SEM 4% and -16 ± 5%, respectively) (P< 0.05). RaEx was not affected by MYC in the first 0–120 min, but during 240–360min RaEx was 14 (± 10)% greater in MYC40 than CON. MYC20 and MYC40 suppressed EGP by 19 ± 7% and 14 ± 5% respectively, compared to CON between 0–120min, and this effect continued into 120–240min for MYC20 but not for MYC40. The present study showed MYC ingestion reduced postprandial EGP, implying that MYC, (or a product of its metabolism) directly affects the liver, particularly given there was no difference between MYC and CON in circulating insulin concentration.