Development of a Functional Germinated Barley Foodstuff from Brewer's Spent Grain for the Treatment of Ulcerative Colitis

A new protein-rich and fibrous foodstuff, germinated barley foodstuff (GBF), made from brewer's spent grain by physical isolation (milling and sieving) contains glutamine-rich protein and hemicellulose. In addition to improving defecation in healthy volunteers and animals, consumption of GBF prevented inflammation and diarrhea in a colitis model, largely by increasing production of luminal short-chain fatty acids and because of its high water-holding capacity. In this study, we evaluated the safety and efficacy of GBF as a novel nutraceutical therapy in the treatment of patients with ulcerative colitis (UC). Patients showed improvement in their clinical activity and endoscopic score and had an increase in stool butyrate content after GBF administration, without any adverse effects. Further, we examined the mechanism of the effect of GBF. GBF was fermented, and butyrate was produced by Eubacterium with the aid of Bifidobacterium in the gastrointestinal tract. The bacterial butyrate production from GBF improved the intestinal barrier function, resulting in mitigation of colitis. GBF may prove valuable when applied as a new functional foodstuff, especially as a nutraceutical in the treatment of UC.