Remarkably, oat bran selectively enhanced the number of probiotic bacteria in milk and maintained overall microbial count over a 28-day storage period. Additionally oats have a high content of soluble fiber in the form of β-glucan, and contain also
arabinoxylans and cellulose which are mainly insoluble fiber. The fibers are not digested in the small intestine, but the soluble β-glucan is believed to increase the viscosity of the food bolus, leading to a slower gastric emptying, enhanced gut fill, and slower absorption of nutrients.