[Lactose absorption and tolerance to different types of yogurts in adults with hypolactasia]

It is known that lactose is better absorbed in yogurts than in milk by lactase-deficient individuals. This fact is due to the presence of beta-galactosidase activity in the yogurts, that are different concerning the caracteristics of the products. Thus, the aim of this study was to verify the absorption and tolerance of lactose in some yogurts consumed by our population. We studied 12 hypolactasic adults who, after diagnostic confirmation, were submitted to three breath hydrogen tests after ingestion of milk and two yogurts with different levels of beta-galactosidase. These activities were determined in each sample utilized. The lactose absorption was evaluated by the measurement of H2 eliminated in the expired air and the tolerance was assessed by the symptoms reported by the participants. The medians of the H2 maximum increment were 20 ppm/min for the milk, 10.5 for yogurt X and 5.5 for the yogurt Y. The area under the curve of H2 concentration presented a median of 960 in the test with milk, 420 with yogurt X and 270 with yogurt Y. These results showed statistically significant differences for milk and the two yogurts and similar among the yogurts. The score for symptoms also were different between the milk and the two yogurts and similar among the yogurts. A statistically significant association between absorption and tolerance was not observed, because many tolerant subjects were malabsorbers of lactose. These data show that lactose in yogurts is better absorbed and better tolerated than lactose in milk, suggesting that our products are similar to those of the literature concerning their capacity of hydrolising lactose "in vivo". In spite of the differences found "in vitro" among the beta-galactosidase, there were no significant differences of absorption and tolerance between the two yogurts studied.