IMPROVEMENT OF LACTOSE DIGESTION IN HUMANS BY INGESTION OF UNFERMENTED MILK CONTAINING BIFIDOBACTERIUM-LONGUM

Fifteen lactose malabsorbers were studied to evaluate the effects of c onsumption of milk containing different strains of Bifidobacterium lon gum on lactose digestion. Influences of different growth substrates, b ile sensitivity, and lactose transport on lactose digestion by bifidob acteria were also investigated. Lactose malabsorption was determined b y measuring breath hydrogen excretion of subjects fed four different t est milks (three of which contained 5 x 10(8) cfu/ml of B. longum) on 4 different d using a randomized, double-blinded trial. Test milks inc luded 1) 400 ml of lowfat milk (control), 2) 400 ml of milk containing B. Longum B6 that had been grown with lactose, 3) 400 ml of milk cont aining B. longum B6 grown with lactose plus glucose, or 4) 400 ml of m ilk containing B. longum ATCC 15708 grown with lactose. beta-Galactosi dase activity was highest in milk containing B6 grown with lactose but was extremely low in milk containing B6 grown with lactose and glucos e. Consumption of milk containing B6 grown with lactose resulted in si gnificantly less hydrogen production and flatulence than occurring aft er consumption of control milk or the milk containing B6 grown with bo th lactose and glucose. Hydrogen production after ingestion of 15708 w as also significantly lower than hydrogen production after ingestion o f the control milk. We concluded that milks containing B. longum might reduce breath hydrogen response and symptoms from lactose malabsorpti on when the culture is grown in a medium containing only lactose to in duce a higher beta-galactosidase level and increase rate of lactose up take.