Fn-type chicory inulin hydrolysate has a prebiotic effect in humans

The partial enzymatic hydrolysis of chicory inulin (GFn; 2 less than or equ al to n less than or equal to 60) yields an oligofructose preparation that is composed of both GFn-type and Fn-type oligosaccharides (2 less than or e qual to n less than or equal to 7; 2 less than or equal to m less than or e qual to 7), where G is glucose, F is fructose, and n is the number of beta( 2-->1) bound fructose moieties. Human studies have shown that feeding GFn-t ype oligomers significantly modifies the composition of the fecal microflor a especially by increasing the number of bifidobacteria. The experiments re ported here were used to test the hypothesis that the Fn-type molecules hav e the same property. During a controlled feeding study, 8 volunteers (5 fem ales and 3 males) consumed 8 g/d of an Fn-rich product for up to 5 wk. Feca l samples were collected and analyzed for total anaerobes, bifidobacteria, lactobacilli, bacteroides, coliforms and Clostridium perfringens. Both 2 an d 5 wk of oligofructose feeding resulted in a selective increase in bifidob acteria (P < 0.01). In addition, a daily intake of 8 g of the Fn-type oligo fructose preparation reduced fecal pH and caused little intestinal discomfo rt.