Effective in vivo hydrolysis of milk lactose by beta-galactosidases in the presence of solid foods.

The feasibility of enzyme replacement therapy with exogenous, food-grade, microbial enzymes at mealtime to effect intragastrointestinal hydrolysis of the lactose from 360 ml of cow's milk consumed with a solid food meal (breakfast cereals) was investigated in adult Guatemalan lactose-malabsorbers using a hydrogen breath-analysis procedure to quantify the completeness of postprandial carbohydrate absorption. Adding 2 g of a commercial preparation of beta-galactosidase from Kluyveromyces lactis at mealtime to milk taken with a refined cereal (cornflakes) and an unrefined cereal (bran) reduced the production of excess breath H2 attributable to lactose maldigestion to a level not significantly different from that achieved with lactose-prehydrolyzed milk. Sucrase, as expected, had no effect on H2 production. A beta-galactosidase from Aspergillus niger was less effective that the K. lactis enzyme for in vivo hydrolysis. Thus, exogenous betagalactosidases can eliminate lactose malabsorption in lactase-deficient individuals even in the presence of solid foods, allowing lactose intolerant persons to consume milk and dairy products without gastrointestinal discomfort.