DIGESTION AND TOLERANCE OF LACTOSE FROM YOGURT AND DIFFERENT SEMISOLID FERMENTED DAIRY-PRODUCTS CONTAINING LACTOBACILLUS-ACIDOPHILUS AND BIFIDOBACTERIA IN LACTOSE MALDIGESTERS - IS BACTERIAL LACTASE IMPORTANT

Objective: To compare the digestibility and tolerance of lactose from three semi-solid fermented dairy products with the same amount of lact ose but different lactase contents and bacterial cultures in lactase d eficient adults. Design: Measurement of breath hydrogen (H-2) concentr ation and of clinical symptoms after consumption of the test meals. Se tting: Metabolic ward for healthy volunteers, INSERM U290, Hopital St. Lazare, Paris. Subjects: Fifteen lactase-deficient healthy adult volu nteers (20-45 y) started the study. One subject became a non-H-2-produ cer during the study; therefore the results of 14 subjects are present ed. Intervention: Each subject consumed, on four different days and in random order, after a 12 h fast, three semisolid test meals containin g 18 g of lactose, and a 10 g dose of lactulose which allowed calculat ion of lactose malabsorption. The three meals were: traditional yoghur t, fermented milk (Ofilus(R)) that contained Lactobacillus acidophilus and Bifidobacterium sp., and a similar product 'Bulgofilus' enriched with Lactobacillus bulgaricus to increase the lactase content. Results : Compared with lactulose, the sum of symptoms was significantly lower for Bulgofilus (P=0.05), and bloating was less severe for Ofilus(R) ( P=0.06). Between the fermented milks, there were no differences. The a rea under the breath H-2 curve was significantly lower for each fermen ted milk when compared to lactulose (P < 0.0001). The degree of maldig estion of lactose did not differ significantly between the products; i t was 21 +/- 3% (range 6-52) for Ofilus(R), 21 +/- 3% (range 6-44) for Bulgofilus, and 18 +/- 3% (range 3-43) for yoghurt. Conclusion: Despi te the differences in the lactase and bacterial content, lactose was a s well digested and tolerated from the three different semi-solid ferm ented dairy products. This could be due to a slow gastric emptying of the semi-solid milk.