Source of the urinary maltose and maltotriose excreted during intravenous infusion of oligosaccharide solutions in young pigs

Pigs infused with preparations of glucose oligosaccharides excrete sizeable quantities of maltose in urine despite the absence of maltose in the infused solution. Maltose infused without other oligosaccharides is well utilized. Our studies examined possible sources of excreted maltose. We first examined whether simultaneous infusion of larger oligosaccharides with maltose inhibits maltose utilization. Four young pigs were infused for four days with 20 g/d of a maltose-free oligosaccharide preparation to which tracer quantities of U- 14C-maltose were added. Urinary excretion of maltose-plus-maltotriose increased significantly ( P < .05) from a mean ± SD baseline value of .01 ± .01 g/d to an overall four-day mean value of 1.33 ± 0.47 g/d. However, only 10.7 ± 0.78% of infused 14C-maltose was excreted, indicating that simultaneous infusion of larger oligosaccharides did not inhibit maltose utilization. The second study examined whether maltotriose present in the oligosaccharide mixture was the source of excreted maltose. Four young pigs were infused for three days with 20 g/d of a special preparation of oligosaccharides containing only frace quantities of maltose and maltotriose. Urinary maltose plus maltotriose excretion increased significantly ( P < .05) from a mean ± SD baseline value of .01 ± .01 g/d to 1.65 ± 0.41 g/d during oligosaccharide infusion. The data suggest that excreted maltose and maltotriose arise from the catabolism of larger oligosaccharides.