Perhaps many people have experienced diarrhea from drinking milk since they don’t know when. I thought I was allergic to milk, but drinking yogurt is fine, or drinking a small glass of milk after a meal is fine. This phenomenon is most obvious in Asians, and it is actually lactose intolerance caused by lactase deficiency.
What is lactose intolerance?
Lactose intolerance is simply explained as an impairment in the digestion of lactose in the intestine, resulting in intestinal symptoms such as flatulence, intestinal cramps or diarrhea. The main cause is lactase deficiency.
For most mammals (including humans), lactase activity is maintained at high levels until 2 years of age, and in most people lactase activity continues until 2-15 years of age and then gradually declines to adult levels, about 10% of normal infant enzyme activity levels.
What happens in the gut with lactose intolerance?
Among the myriad of enzymes that help break down food in the human intestine, lactase is the least mature, least abundant, most impaired, and slowest to recover of the small intestinal mucosal disaccharidases, and is closely related to human health.
Lactose is hydrolyzed by lactase into galactose and glucose and then absorbed by the body. When the lactase enzyme of small intestine mucosa is lacking or its activity is reduced, lactose cannot be decomposed and stays in the intestine, where it is fermented and decomposed by intestinal bacteria into lactic acid and CO2 and other gases.
The role of lactose
1.Lactose is present in the milk of most mammals and contains about 7% in human milk, it is the main carbohydrate in breast milk and provides energy for the body;
2, lactose promotes the absorption and utilization of calcium, iron, zinc and other minerals;
3, maintain the micro-ecological balance in the intestinal tract;
4, lactose is broken down after the galactose or infant brain development of essential substances.
Secondary lactose intolerance in infants and young children
In infants and young children, secondary lactose intolerance caused by intestinal infections is common, and lactose intolerance caused by rotavirus enteritis is the most common. Rotavirus not only destroys the intestinal mucosa and reduces the secretion of lactase, but also acts directly on lactase to destroy and decompose it, causing secondary lactose intolerance and prolonging diarrhea.
Main symptoms and effects of lactose intolerance
1, infants and young children common symptoms for diarrhea, typical stool is yellow thin stool, with foam and sour smell. In older children, abdominal discomfort and bloating are common. The diarrhea disappears a few days after the lactose removal diet.
2, secondary lactose intolerance caused by diarrhea, once the diarrhea of children with breast milk or milk powder as the main food, will not improve for a long time, often need to switch to lactose-free milk powder, diarrhea can slowly improve.
3. Lactase deficiency also affects the absorption of calcium in the small intestinal tissues, thus causing calcium deficiency or rickets in children.
Treatment of lactose intolerance
1. Reduce or avoid dairy products, or switch to lactose-free/low-lactose milk powder, and use cereals, soy milk or soy foods and meat and other lactose-free foods as the main food. And for infants and toddlers under 2 years old who are fed mainly on milk, they can switch to lactose-free milk powder.
2, probiotics: a variety of probiotics and lactase related, lactic acid bacteria can produce lactase, for lactose intolerance treatment has a good effect, pharmacies are also easy to buy. You can also eat “yogurt”, which contains a high number of active lactobacilli, is also an important source of probiotics.
3, lactase: take lactase before each meal or before drinking milk to relieve symptoms, or add lactase (liquid preparation) to milk and drink it overnight in the refrigerator to break down most of the lactose in milk.
Is it true that a diagnosis of lactose intolerance means you can’t drink milk?
Studies have found that even in patients with severe lactose intolerance, eating up to 6.5-12.5 mg of lactose per day, equivalent to no more than 125-250 ml of milk, and when eaten with other things, often does not cause symptoms.