β-galactosidase is an enzyme that helps break down lactose, a sugar found in milk and dairy products. It catalyzes the hydrolysis of lactose into its simpler sugars, glucose and galactose, making it easier for the body to digest. This enzyme is particularly important for individuals who are lactose intolerant, as it can alleviate digestive discomfort by aiding in lactose digestion. This enzyme is produced by various organisms, including E. coli and yeast. In laboratory settings, β-galactosidase is often used as a reporter gene in molecular biology experiments, helping researchers track gene expression and activity. Its role in biotechnology and food industries is also significant, as it improves the digestibility of dairy products.