Absorption of lactose and its digestion products i the normal and malnourished Ugandan.

Primary or specific lactase deficiency is very common in healthy members of the Baganda and other Bantu tribes of Uganda after the first three or four years of life (Cook and Kajubi, 1966; Cook, 1967). Secondary lactase deficiency has been recorded in some cases of kwashiorkor (Bowie, Brinkman, and Hansen, 1965; Stanfield, Hutt, and Tunnicliffe, 1965), where there is mucosal damage in the proximal jejunum. The functional importance of the lactase deficiency in both of these situations is not yet clear. The lactose-tolerance test has been widely used as a screening test for lactase deficiency and it is important to establish its true value. Several investigators have found a good correlation between the lactase level in specimens of jejunal mucosa and the maximum rise in blood glucose after lactose (Dunphy, Littman, Hammond, Forstner, Dahlqvist, and Crane, 1965; McMichael, Webb, and Dawson, 1965, 1966; Peternel, 1965; Cook and Kajubi, 1966; Welsh, 1966). Others have not found such a good association (Friedland, 1965; Newcomer and McGill, 1966a). The present study was undertaken to assess the relationship between the rise in capillary blood glucose and percentage absorption of lactose digestion products from the jejunum after oral lactose. By an intubation technique the amount of unabsorbed lactose in the jejunum was measured. In a few subjects jejunal disaccharidase levels were also estimated. Two groups were studied: a series of relatively normal Ugandan hospital patients, and a group of children with mild to moderately severe kwashiorkor.