MANAGEMENT OF LACTOSE MALDIGESTION BY CONSUMING MILK CONTAINING LACTOBACILLI

The influence of nonfermented milk containing L. acidophilus or L. bul garicus on lactose utilization by lactase maldigesters was investigate d. Nonfermented milks containing L. acidophilus or L. bulgaricus at 10 (8) and 10(9) CFU/ml were prepared using 2% low-fat milk. Lactose mald igestion was monitored by measuring breath hydrogen at hourly interval s for 8 hr following consumption of 400 mi of each diet. Nonfermented milk containing L. acidophilus B at 10(8) CFU/ml were not effective in reducing breath hydrogen and symptoms. Nonfermented milk containing L . acidophilus B at 10(9) CFU/ml only slightly decreased breath hydroge n production; however, the symptoms were significantly improved. Nonfe rmented milks containing L. bulgaricus 449 at 10(8) and 10(9) CFU/ml w ere effective in reducing breath hydrogen and symptoms. The results fo r bulgaricus milk were all significant. In this study, L. acidophilus B and L. bulgaricus 449 were chosen because of their similar beta-gala ctosidase activity and bile sensitivity. L. acidophilus and L. bulgari cus are both thermophilic lactobacilli and an active transport (permea se) system is found in both species for lactose transport. The major f actor affecting in vivo lactase digestion in this study appears to be the bacterial cell wall/membrane structures. That the cell wall/membra ne structures of L. acidophilus are different from those of L. bulgari cus can be indirectly proven by the results of sonication time for max imum beta-galactosidase activity measurement. The results of this stud y indicate that L. bulgaricus is usually a better choice than L. acido philus for manufacturing nonfermented milks for lactose maldigesters.