Effects of wheat pentosan and inulin on the metabolic activity of fecal microbiota and on bowel function in healthy humans

The effects of wheat pentosan and inulin on the metabolic activity of fecal microbiota and on bowel function were compared in healthy humans. In a parallel study 14 subjects consumed daily for three weeks 13 g of wheat pentosan or inulin baked in wheat bread. Activities of bacterial enzymes (β-glucuronidase, β-glucosidase, urease) and concentrations of bacterial metabolites (short chain fatty acids, phenol, p-cresol) in feces, bowel function and intestinal symptoms were measured at the beginning and end of the intervention period. Changes in most parameters studied were similar in subjects receiving pentosan or inulin bread, but pentosan increased total SCFA (P = 0.048) and butyrate (P = 0.009) concentrations in feces more than inulin. Pentosan also increased the occurrence of flatulence (P < 0.05). Pentosan appears to be more easily fermented than inulin, and due to the increase in the fecal butyrate concentration may have favourable effects on colonic health.