Effects of Short-Term Intake of Wheat Bran with Different Particle Sizes on the Murine Intestinal Environment

Wheat bran has a high dietary fiber content. In this study, we investigated the effects of short-term intake of wheat bran on intestinal environment in a murine model. Mice were fed with AIN-93G for 1 week, followed by experimental diets containing wheat bran with an average particle size of 53 mu M (powdered) or 350 mu m (granulated) for 1 additional week. During a 4-week period (twice-repeated feeding cycles), the ratio of bacteria belonging to the families Prevotellaceae and S24-7 increased in murine feces after intake of both particle-size diets. Furthermore, the amount of short fatty acids, particularly butyric acid, and cecal immunoglobulin A were significantly increased in the powdered wheat bran group, probably by the changes in intestinal microbiota composition. These findings may potentially explain many of the health benefits through the alteration of intestinal microbiota, even after short-term intake of wheat bran.