Dietary resistant starch attenuates perturbations in carbohydrate and methyl group metabolism in type 1 diabetic rats

Abstract

Type 1 diabetes (T1D) is characterized by aberrant carbohydrate metabolism owing to a lack of insulin production. Recently, it has also been shown that T1D in the streptozotocin (STZ)‐treated rat results in abnormal methyl group metabolism. Because previous reports have demonstrated that dietary resistant starch (RS) can attenuate hyperglycemia in type 2 diabetes, the focus of this study was to determine if RS could provide glycemic control in a STZ‐T1D rat model, as well as have an impact on methyl group metabolism. Male Sprague Dawley rats were acclimated to a 0, 37, or 71% RS (RS‐0, RS‐37, RS‐71, respectively) diet for 10 d. All starches were provided at 550 g/kg diet. After the acclimation period, half of the RS‐0 rats, and all of the RS‐37 and RS‐71 rats were injected with STZ (60 mg/kg body weight). After 15 d, rats were anesthetized, whole blood samples were obtained by cardiac puncture, and tissue samples rapidly removed for analysis. Diabetic rats fed either the RS‐37 or RS‐71 diet exhibited significantly less weight loss compared to those fed the RS‐0‐based diet. Moreover, both RS‐37‐ and RS‐71‐fed diabetic rats exhibited significantly lower blood glucose concentrations compared to diabetic rats fed the RS‐0 diet. Thus, RS appears to be an effective dietary component that can attenuate diabetes and related metabolic alterations in T1D diabetic rats. Support: Plant Sciences Institute, Iowa State University.