title: Yogurt and fermented-then-pasteurized milk: effects of short-term and long-term ingestion on lactose absorption and mucosal lactase activity in lactase-deficient subjects.
abstract: Lactase-deficient subjects absorb lactose in yogurt more effectively than lactose in other dairy products. However, as all previous studies were performed without a double-blind design and only after a single ingestion of the test product, the mechanism of this enhanced absorption remains unclear. The aims of this double-blind study were 1) to evaluate lactose absorption after prolonged ingestion of yogurt and fermented-then-pasteurized milk (FPM) and 2) to assess the modification of the lactase activity of the duodenal mucosa. In 16 lactase-deficient subjects we confirmed that yogurt enhances lactose digestion, this beneficial effect being destroyed by pasteurization. Moreover, the long-term (8 d) ingestion of either yogurt or FPM does not modify the results of hydrogen breath tests in comparison with a 24-h ingestion. The mucosal lactase (Dahlquist method) and beta-galactosidase (ONPG method) activities were not significantly modified by yogurt or FPM ingestion. These results suggest that in lactase-deficient subjects no adaptation occurs after eating yogurt or FPM and that the increased lactose absorption in yogurt must be mainly related to an intraluminal process.
authors.affiliation: Groupe de Biochimie et de Physiologie Digestive et Nutritionnelle, Rouen, France.
authors.forename: E
authors.initials: E
authors.lastname: Lerebours
authors.forename: C
authors.initials: C
authors.lastname: N'Djitoyap Ndam
authors.forename: A
authors.initials: A
authors.lastname: Lavoine
authors.forename: M F
authors.initials: MF
authors.lastname: Hellot
authors.forename: J M
authors.initials: JM
authors.lastname: Antoine
authors.forename: R
authors.initials: R
authors.lastname: Colin
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001944:Breath Tests; D002986:Clinical Trials as Topic; D003611:Dairy Products; D004311:Double-Blind Method; D004386:Duodenum / Q000201:enzymology; D005285:Fermentation; D005696:Galactosidases / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D006859:Hydrogen / Q000032:analysis; D066298:In Vitro Techniques; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000201:enzymology*; D007785:Lactose / Q000378:metabolism*; D007787:Lactose Intolerance / Q000201:enzymology / Q000378:metabolism*; D008892:Milk; D013997:Time Factors; D015014:Yogurt; D001616:beta-Galactosidase / Q000032:analysis / Q000378:metabolism*
chemical_list: D006859:Hydrogen; D005696:Galactosidases; D001616:beta-Galactosidase; D007785:Lactose