A New Resistant Starch Material Obtained from Faba Beans (Vicia faba L. Creole): Potential Modulation of the Diabetic Condition in Diabetic Wistar Rat Model

Background: Resistant starch, and specially retrograded starches (RS), have been suggested as useful biological molecules to improve the glucose management in diabetic conditions. However, the influence of the botanical origin in the RS biological capacities make necessary its evaluation, where RS from legumes have been paid less attention compared to other sources as cereals. Objectives: A RS product obtained from creole Faba beans (Vicia faba L. creole), was evaluated for the first time as a material capable of improving glucose homeostasis in diabetic conditions. Methods: The RS ingredient investigated (with a reduced digestibility of 50%) was tested in a Wistar rat model with induced diabetes, fed with a 15 or 30% replacement of RS ingredient in the diet. Diverse nutritional and biomarkers were analysed. Results: As a result of the reduced digestibility of the RS ingredient, diabetic animals fed with RS replacement (15% or 30%) showed attenuated postprandial hyperglycemia responses, reducing the hyperglycemic condition close to 29% compared to non-treated diabetic animals (24.56 ± 7.50 and 25.02 ± 3.54 vs. 34.65 ± 1.89 mmol/L, respectively). In addition, fasting serum glucose levels were significantly reduced (22%). Other biochemical parameters associated with glucose metabolism, such as glycosylated hemoglobin and AGEs levels, also improved. Furthermore, significant improvements in nutritional parameters (such as weight gain) and a lower insulin resistance index were determined. In contrast, no clear effects were observed in lipid metabolism and oxidative stress biomarkers in the treated group. Conclusions: The results of this research suggest that the retrograded starch from creole beans evaluated could be a potential functional food ingredient capable of enhancing glucose homeostasis in diabetic conditions.