Protein, and dietary fiber-rich new foodstuff from brewer's spent grain increased excretion of feces and jejunum mucosal protein content in rats.
Biosci Biotechnol Biochem. 1997 Jan;61(1):29-33.
Kanauchi O, Agata K.
Applied Bioresearch Center Corporate Research and Development Division, Kirin Brewery, Co., Ltd., Gunma, Japan.

We made a new protein-rich and fibrous foodstuff by milling and sieving brewer's spent grain. This product contained glutamine-rich protein and the dietary fibers cellulose, hemicellulose, and lignin. We called this product germinated barley foodstuff (GBF). GBF had the effect of increasing fecal dry weight and number of feces and of significantly increasing jejunum mucosal protein content in rats over the cellulose group. In GBF, Gln-rich protein is thought to have strong chemical bonds with dietary fiber, an arrangement which would be important in the way these physiological effects arise. As dietary supplements of Gln or dietary fibers (i.e., cellulose, hemicellulose, lignin, and a mixture of these) did not improve defecation and jejunum mucosal protein simultaneously, the effects of GBF are thought to be caused not by the individual ingredients, but by the combination of protein with dietary fiber.