Consumption of a high β-glucan barley flour improves glucose control and fatty liver and increases muscle acylcarnitines in the Zucker diabetic fatty rat

Abstract

The soluble fiber β-glucan, a natural component of barley, has been shown to lower the postprandial glucose response and is thought to improve insulin resistance. This study examined the effect of chronic consumption of the high β-glucan barley flour on glucose control, liver lipids and markers of muscle fatty acid oxidation in the Zucker diabetic fatty (ZDF) rat. Two groups of ZDF rats were fed diets containing either 6% β-glucan in the form of barley flour or cellulose as a control for 6 weeks. A group of Zucker lean rats served as a negative control. The barley flour group had an increased small intestinal contents viscosity compared to the obese control group. After 6 weeks, the barley flour group had reduced glycated hemoglobin, lower relative kidney weights and a reduced area under the curve during a glucose tolerance test, indicating improved glucose control. Fasting plasma adiponectin levels increased in the barley flour group and were not different than the lean control group. ZDF rats on the barley flour diet had lower relative epididymal fat pad weights than the obese control and a greater food efficiency ratio. The barley flour group also had reduced liver weights and a decreased concentration of liver lipids. The barley flour group had significantly higher concentrations of muscle acylcarnitines, a metabolite generated during fatty acid oxidation. These results show that chronic consumption of β-glucans can improve glucose control and decrease fatty liver in a model of diabetes with obesity.