First identified in 1929, Lactulose came to prominence for the treatment of constipation in 1959. Lactulose is a synthetic sugar, which does not occur naturally. The disaccharide lactulose (galacto-fructose) is synthesised from lactose (galacto-glucose) by isomerisation of glucose to fructose. Each molecule of galactose is linked to a molecule of fructose.
These linked monosaccharides are the reason why lactulose cannot be degraded by animal or human enzymes and reaches the colon unchanged with only few available calories.
Lactulose, how does it work?
Lactulose reaches the colon unchanged, where the bacteria of the intestines metabolise it, producing a number of short chain fatty acids. This process initiates a large number of effects in the gastrointestinal tract:
Lactulose is a carbohydrate and energy source for colonic saccharolytical bacteria. Bifidobacteria and Lactobacilli metabolise Lactulose into several SCFA (short chain fatty acids). Total biomass, stoole volume and osmotic pressure is increased and pH is decreased resulting in a accelerated bowel movements and shorter transit time.
Ammoniac binding
Lactulose inhibits bacterial ammonia production by acidifying the content of the bowel. It promotes growth of colonic flora. The growing biomass uses ammonia and nitrogen from amino acids to synthesise bacterial protein, which in turn inhibits protein degradation to NH3. Lactulose leads to less ammonia by inhibiting bacterial urea degradation and reduces colonic transit time, thus reducing the time available for ammonia production and expediting ammonia elimination.
Pre-biotic
In the colon, undigested lactulose carbohydrates are the ideal nutritional basis for health-promoting bacteria in the bowel flora, e.g. bifidobacteria and lactobacilli. This can result in a large number of positive effects as intact intestinal barrier, stabilisation of the immune system, strengthened immune system, reduced susceptibility to illness and many more.
