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Updated: Aug 8, 2026

Measuring Lactase Enzymatic Activity in the Teaching Lab
Published on: August 6, 2018
Abstract:
The tests with lactose loading followed by the assay of blood sugar were conducted in 500 normal subjects, aged from 18 to 89 years, and 262 patients with gastro-intestinal diseases, aged from 25 to 55 years. When lactose malabsorption was detected, aspiration biopsy of the small intestine mucosa was performed followed by the study of the structure and the level of a number of disaccharidases (lactase, maltase, saccharase). Lactose malabsorption was detected in 72 (14.4%) out of 500 normal subjects (10.6%--aged 18-59, and 20%--aged 60-89 years), among them there were 12.5% of Russians, 13% of Byelorussians and 5.8% of Ukrainians (aged 25-55 years). The secondary lactose malabsorption was recorded in 44% of patients with ulcerative colitis, in 33% of patients with chronic enterocolitis, in 11.5% of patients with gastric ulcer, in 8% of those with duodenal ulcer, in 23.5% of patients with chronic gastritis attended by lowered secretory function, and in 8% of those with enhanced secretory function.
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