Lactulose is a synthetic disaccharide composed of one galactose molecule and one fructose molecule linked by a β1→4 glycosidic bond (2). Since lactulose is not naturally occurring, lactose, composed of glucose and galactose, is often used as a precursor molecule for lactulose production. In order to produce lactulose from lactose, lactose isomerization must occur in which the galactose subunit is removed from lactose and joined to a fructose molecule. Lactose isomerization can be carried out using chemical or enzymatic methods. Chemical methods use an alkaline catalyst, such as sodium hydroxide or potassium hydroxide, in combination with a complexing agent, such as borate or aluminate, which will attach to the lactulose and precipitate as an insoluble complex from the reaction system, thereby shifting the chemical balance in favor. the formation of the lactulose product; Synthesis of lactulose by this method can result in a yield of up to 80% lactulose. Enzymatic methods achieve lactose isomerization via transgalactosylation using β-galactosidases, which hydrolyze the β1→4 glycosidic bond of lactose. In the presence of fructose, the galactose subunit of lactose is ideally added to the hydroxyl group of all four carbon atoms of fructose to form lactulose. However, the addition of galactose to fructose is not limited to the main four carbon atoms because fructose contains other hydroxyl groups on several carbon atoms; therefore, enzymatic isomerization of lactose can produce various constitutional isomers of lactulose containing β1→1 or β1→6 glycosidic linkages (3). The β1→4 glycosidic bond of lactulose is crucial for its function in humans and animals. The mucous membranes that line the top and middle of the paper......ely metabolized by beneficial bacteria in the colon, such as bifobacteria and lactobacilli, which are essential for maintaining a healthy body (3).Lactulose is safe for short- and long-term use at all ages, from infants to the elderly (1, 2). Overconsumption of lactulose can cause excessive diffusion of water in the intestines and lead to diarrhea. However, this side effect can be corrected by administering a lower dose of lactulose (1). Works Cited (1) Elkington, SE (1970). “Lactulose”. Gut 11 (1970): 1043-1048(2) Panesar, PS and Kumari S. (2011). “Lactulose: production, purification and potential applications”. Biotechonology Advances 29 (2011): 940-948(3) Schuster-Wolff-Bühring, R., Fischer, L. and Hinrichs, J. (2010). "Production and physiological action of the disaccharide lactulose". International Dairy Review 20 (2010): 731-741