Effect of casein-derived peptides on D-xylose absorption assessed by H2 breath test in normal volunteers.

Studies have shown a promoting effect of food on small intestinal absorption. Casein hydrolysate seems be more effective in increasing of D-xylose absorption in dogs than the whole protein and lactulose. The purpose this study was to analyze the effect of groups of peptides derived from casein hydrolysate on the absorption of D-Xylose and intestinal transit time in normal subjects. Seven normal volunteers participated in the study. Three peptide fractions were isolated from casein enzymatic hydrolysate by means of a preparative HPLC silica column. On separate days subjects drank test solutions containing lactulose, D-xylose, and D-xylose with one of three peptide groups. The hydrogen breath test was used to indirectly estimate D-xylose absorption and orocecal transit time. Two peptide fractions when added to D-xylose were followed by an increased absorption characterized by decreased H2 production. A nonstatistically significant increase of orocecal transit time was observed with these peptides.