Lactulose - a disaccharide consisting of galactose and fructose, is not hydrolyzed by the disaccharidases of the small intestine mucosa. Has a hyperosmotic laxative effect, stimulates the intestinal peristalsis, improves the absorption of phosphates and calcium salts, promotes the excretion of ammonium ions.
Lactulose is cleaved by intestinal flora of the colon to low-molecular organic acids, which leads to a decrease in pH and an increase in osmotic pressure and. as a consequence, an increase in the volume of intestinal contents. These effects stimulate intestinal peristalsis and affect the consistency of the stool. The physiological rhythm of emptying of the large intestine is restored.
In hepatic encephalopathy, the effect is attributed to the suppression of proteolytic bacteria by increasing the number of acidophilic bacteria (eg, lactobacilli), the transition of ammonia to the ionic form by acidifying the contents of the colon, emptying the bowels due to a decrease in pH in the large intestine and osmotic effect, and also reducing the nitrogen-containing toxic substances by stimulating bacteria that utilize ammonia for bacterial protein synthesis.
Lactulose as a prebiotic substance enhances the growth of beneficial bacteria such as bifidobacteria and lactobacilli, while it becomes possible to suppress the growth of potentially pathogenic bacteria such as Clostridium spp. and Escherichia coli, which provides a more favorable balance of intestinal flora.