Resumen
The invention relates to the use in humans of a method which is based on the use of 4-galactosyl-xylose and which involves an alternative technique to determining xylose in urine. The method consists in measuring the concentration of xylose in the blood following the oral administration of 4- galactosyl-xylose to the patient, the use of said method being even more suitable in the case newborns. The invention also relates to the technology used for the in vivo evaluation of intestinal lactase activity, by way of a non-invasive test for the diagnosis of a deficiency of said enzyme, which consists in directly evaluating the overall activity of the enzyme in the individual and not in assessing the consequences of said deficiency. The inventive method does not require specialist equipment, does not cause any obvious discomfort to patients with a lactase deficiency and is extremely reliable, thereby eliminating the inconveniences of currently-used diagnosti c tests.