Effects of Oats and β-Glucan on Gut Health

Grains are typically the largest contributor to dietary fiber intake and are also high in resistant starch and oligosaccharides. Oats, in particular, contain considerable amounts of soluble fiber, which appear to have lipid-lowering and glucose-modulating effects. In addition, oats increase stool weight, speed intestinal transit, modify gut microflora, and serve as substrate for bacteria that produce short chain fatty acids. In vitro fermentation studies show that carbohydrates in oat bran (rich in β-glucan) are more rapidly consumed by bacteria than carbohydrates of rye and wheat brans (rich in arabinoxylan). However, oat fiber is fermented more slowly than inulin, resulting in less gas production. In vivo studies have demonstrated whole grain breakfast cereals (including oats) are more effective than wheat bran breakfast cereal as prebiotics, increasing fecal bifidobacteria and lactobacilli in human subjects. Taken together, these findings demonstrate that consuming oats is beneficial to gut health.