A Study of the Effects of Dietary Fiber in Cereals for Improvement of Obesity Parameters

(JSNFS Award for Excellence in Research (2022))

Abstract

The effects of fiber intake from cereals, specifically barley and wholegrain wheat, on obesity parameters were investigated through human intervention studies. A series of experimental animal studies were also performed to investigate the mechanism responsible for the anti-obesity effects of barley. Our human intervention studies have revealed some evidence of effects such as: (1) suppression of the postprandial rise in blood glucose level (rice with barley and wholegrain wheat bread); (2) the maintenance of satiety (foods containing barley); (3) reduction of abdominal fat (rice with barley and wholegrain wheat bread); and (4) modification of gut microbiota (wheat bran and foods containing barley). Animal experiments have shown that both high- and low-molecular-weight barley β-glucans have anti-obesity effects. However, the former is due mainly to inhibition of dietary lipid absorption as a result of viscosity, and the latter to the action of short-chain fatty acids through intestinal fermentation. It was confirmed that the improvement of glucose intolerance resulting from intake of barley flour was attributable to an increase of short-chain fatty acids as a result of intestinal fermentation, thus increasing the secretion of glucagon-like peptide-1 (GLP-1).