lactulose

Lactulose is a synthetic disaccharide composed of galactose and fructose that functions as both an osmotic laxative and a prebiotic. It is not absorbed in the upper gastrointestinal tract and reaches the colon intact, where it is fermented by commensal bacteria, particularly *Bifidobacterium* and *Lactobacillus* species. This fermentation produces short-chain fatty acids (such as lactic and acetic acids), which lower the colonic pH and exert an osmotic effect, drawing water into the lumen to soften stools and stimulate peristalsis. Beyond its primary use in chronic constipation, lactulose is a cornerstone therapy for hepatic encephalopathy; the acidified colonic environment converts ammonia (NH3) into non-absorbable ammonium ions (NH4+), effectively trapping it for excretion. Recent clinical research has explored its utility in modulating the gut-brain axis in Parkinson's disease, reducing uremic toxins in chronic kidney disease, and acting as an adjuvant therapy in inflammatory bowel disease.

Brand names

KristaloseDuphalacEnuloseGenerlacConstuloseCholacChronulac

Other names

4-O-beta-D-galactopyranosyl-D-fructoselactulose syruplactulose oral solutioncrystalline lactulose