Gastrointestinal effects of immature wheat grain fructo-oligosaccharides

Research on functional cereal grains has focused on immature wheat grains (IWG), natural source of fructo-oligosaccharides (FOS). These undigestible carbohydrates are defined “prebiotics” for their properties on gut health. The prebiotic effect of IWG biscuits was tested “in vitro”. 50g of two experimental biscuits (IWG and control) were served at breakfast with 300 ml of tea to three healthy ileostomates. Effluents, recovered for 8 hour, were pooled into two fermentation mix (control and IWG) and used as fermentation medium. Mix were inoculated, anaerobically, with fresh faeces from 6 healthy volunteers and incubated at 37°C for 24 hours. Bifidobacteria and Lactic Acid Bacteria counts were evaluated by FISH technique and SCFA production was assessed by GC. Bifidobacteria and Lactic Acid Bacteria counts were higher (p<0.05) in IWG than in control mix, supporting the prebiotic effects of FOS; IWG fermentation promotes acetate production. Since colonic fermentation may delay gastric emptying, we investigated whether IWG biscuits, eaten at breakfast, modify gastric emptying of the main meal. Twelve healthy volunteers underwent ultrasound measurement of gastric emptying of a 800 Kcal meal, consumed 5 hours after a breakfast based on lactose-free milk and IWG or control biscuits; hunger and fullness sensations were also evaluated. FOS delayed gastric emptying of the main meal (p<0.05), decreased hunger (p<0.001) and increased fullness (p<0.005) in the period before the main meal. These data support IWG use in preparing functional prebiotic breakfast products probably able to promote second meal effect and to reduce the overall daily caloric intake