Lactose is sometimes referred to as “milk sugar” because it is only found naturally in the milk of mammals—including cows, goats and humans. Milk from cows and goats is used to make cheese and yogurt, but not all milk products contain the same amount of lactose. For example, hard cheeses such as cheddar, parmesan and Swiss contain very little or no lactose, whereas milk, ice cream and. Learn about the symptoms, diagnosis, and treatment of an intolerance to the natural sugar in milk and how lactose intolerance differs from allergy. Lactose is a natural, complex sugar produced in all mammalian milk that’s difficult to breakdown unless you have lactase, a protein, in your small bowel. Lactose is a disaccharide composed of galactose and glucose and has the molecular formula C 12 H 22 O 11. Lactose makes up around 2–8% of milk (by mass). The name comes from lac (gen. lactis), the Latin word for milk, plus the suffix -ose used to name sugars. The compound is a white, water-soluble, non- hygroscopic solid with a mildly sweet. Lactose intolerance is a condition that makes it hard to digest the sugar in milk and milk products, called lactose. People with lactose intolerance often have diarrhea, gas and bloating after eating or drinking foods containing lactose. The condition is usually harmless, but its symptoms can cause discomfort. Too little of an enzyme made in the small intestine, called lactase, is usually. Find out about lactose intolerance, what the symptoms are, what the treatments are, what tests can find out if you have it, and what causes it. What is Lactose and Lactose Intolerance? Lactose is a sugar found in some dairy products. Lactase is an enzyme in the gut that is needed to break down lactose. Many adults have trouble digesting foods with lactose because their level of lactase goes down after childhood, which is normal. People with intestinal disease or injury may also become lactose intolerant, even if they were not before. Lactose-free milk is regular cow’s milk that has undergone a process to break lactose down into simple sugars (glucose and galactose). This is achieved by adding the lactase enzyme directly to the milk. Learn about lactose intolerance, a condition in which you have symptoms—such as bloating, diarrhea, and gas—after you consume foods or drinks that have lactose. Lactose is a sugar naturally found in dairy products like milk, butter, yogurt, and more. Learn which 5 foods to avoid for lactose intolerance.