Lactose intolerance is a common pathology that occurs due to the reduced activity of β-galactosidase leaving undigested lactose in the intestine. About 70% of the world population suffers from this condition. The gastro intestinal symptoms associated with this condition are diarrhoea, pain, nausea, bloating, flatulence, etc. It has been reported that these individuals are at a risk of developing several other pathologies like irritable bowel disease, osteoporosis, etc. Hence, proper diagnosis and treatment is essential for dealing with this condition. Various methods are used for providing an accurate diagnosis, such as hydrogen breath test (HBT), lactose intolerance test, genetic test, intestinal biopsy, etc. Depending on the type of intolerance, several methods are adopted for treating it, such as replacing enzyme, using exogenous enzymes, following lactose free diet, as well as consuming prebiotics and probiotics. Different methods are applied to synthesize lactose free dairy products to help lactose intolerant individuals suffering from important vitamins and minerals deprivation. Recently, plant-based milks are also used as a substitute for providing calcium and vitamins. The last few years have seen improvement in the quality and availability of lactose-free dairy products offering tempting foodstuffs to consumers. This narrative article aimed to review the existing science on lactose intolerance, along with its epidemiology, diagnosis, and clinical management.
Keywords: β-Galactosidase, Lactase, Lactose intolerance, Lactose maldigestion, Lactase non-persistence, Lactose-free products,