Lactase is an enzyme produced in the small intestine that helps break down lactose, a sugar found in milk and dairy products. When lactose is consumed, lactase splits it into two simpler sugars, glucose and galactose, which can then be easily absorbed into the bloodstream. In some individuals, the body produces insufficient lactase, leading to a condition known as lactose intolerance. This can result in digestive issues such as bloating, gas, and diarrhea after consuming dairy. People with lactose intolerance may choose lactose-free products or take lactase supplements to aid digestion.