Lactose intolerance

Lactose deficiency is the failure to express the enzyme that hydrolyses lactose into galactose and glucose in the small intestine ( Misselwitz B et al Nov 2019 )

What is it ? Lactose is the main carbohydrate in human and mammalian milk Lactose is the main source of calories in milk Normally when lactose is consumed it is hydrolyzed to glucose and galactose by lactase enzyme Lactase-phlorizin hydrolase → known as lactase is a beta-galactosidase -found in the small intestinal brush border These are absorbed by intestinal blood stream○ glucose used as source of energy○ galactose becomes component of glycolipids and glycoproteins Reduced intestinal lactase results in malabsorption of lactose →Unabsorbed lactose →Metabolised by colonic bacteria →Produces gas and short chain fatty acids → leading to the clinical manifestation Abdominal cramps , bloating , diarrhoea , flatulence It is not a cause of rectal bleeding

How common ?

Acquired primary lactase deficiency is considered to be highly prevalent - affects approximately 65 to 74 % of the world population Rare in children younger than 5 yrs of age Prevalence is variable among different ethinicities Nearly 100 % of patients with Asian , African or Native-American ancestry develop primary lactase deficiency...