I. What is lactose intolerance
Lactose intolerance is a non-infectious diarrhea caused by the inability to completely digest and break down lactose in breast milk or cow’s milk due to low lactase secretion, also known as lactase deficiency.
Lactase deficiency is a widespread worldwide problem with a high incidence in Far Eastern populations, most of whom do not show symptoms, but diarrhea and other symptoms often occur in newborns and infant babies whose diet is primarily based on breast milk.
The peak age range for the occurrence of lactose intolerance varies in different countries, from 7-8 years old in Japan to 3-5 years old in Africa, and a survey of 1168 healthy children aged 3-13 years old in four major cities of Beijing, Shanghai, Guangzhou and Harbin in China suggests a high incidence of lactase deficiency, with 87% of children with lactose intolerance Lactose intolerance occurs at the age of 7-8 years.
II. How lactose intolerance develops
The sugar in breast milk and cow’s milk is mainly lactose, and the secretion of lactase at the tip of the mucosal surface of the small intestine, especially the jejunum, is reduced or not active enough to completely digest and decompose lactose in milk, and some of the lactose is fermented by colonic flora into lactic acid, hydrogen, methane and carbon dioxide.
Lactic acid stimulates the intestinal wall and increases intestinal peristalsis and diarrhea occurs. Carbon dioxide produces flatulence and increases peristalsis in the intestinal tract, causing the baby to act restlessly and occasionally inducing intestinal cramps and colic. The increase in lactic acid also lowers the pH value of the stool.
Third, what kinds of lactose intolerance
Generally, there are three types: congenital lactase deficiency, secondary lactase deficiency, and adult-type lactase deficiency.
Congenital lactase deficiency is caused by congenital deficiency or insufficient activity of lactase, and the incidence is related to race and heredity and belongs to autosomal recessive inheritance. Lactose intolerance in our newborns mostly belongs to this category, and the severity of symptoms varies as the amount and activity of the enzyme deficiency varies from person to person.
Secondary lactase deficiency mostly occurs after enteritis, when the tip of the intestinal villi is damaged during enteritis and enzyme deficiency occurs, and lactose intolerant diarrhea occurs after enteritis, and diarrhea only stops after the lower end of the villi grows up to the tip and can secrete sufficient amount of lactase, which usually takes about 0.5-2 months. Many newborns and preterm infants have a high number of bowel movements during the neonatal period because of the immaturity of the intestinal mucosa and the temporary low activity of lactase, which leads to a high number of bowel movements and a decrease in the number after the activity is normalized.
Adult lactase deficiency is due to the gradual decline or disappearance of lactase activity after a certain age, and its incidence varies with race and region. The incidence varies with race and region. For example, it is about 5%-30% in white Europeans, 76%-10% in yellow Asians, and 95%-10% in Africa.
Fourth, what are the manifestations of lactose intolerance
The main symptom is diarrhea several times a day to more than 10 times a day, most babies have more intestinal gas and often bring out a small amount of feces on the diaper. The stools are mostly yellow or greenish thin paste, or egg-flake soup-like, foamy, with milk lumps, and a few babies have milk reflux or vomiting.
The baby will also have abdominal distension and varying degrees of restlessness and crying, which improves with bowel movements or after diarrhea treatment. Colic is often rare and often occurs during the course of the disease, but can also occur before diarrhea.
Severe cases can occur dehydration, acidosis, growth retardation, etc., mostly without fever.
Five, how to determine the baby has lactose intolerance
Lactose intolerant babies mainly have diarrhea, which can be accompanied by easy crying, vomiting and occasional colic; negative stool routine tests, positive reducing sugar, low pH value suggest lactose intolerance; good treatment of lactose-free formula, and diarrhea after switching to regular formula or breastfeeding. In line with the above, it can be determined that the baby has lactose intolerance.
Six, need to distinguish with which disease
1, enteritis: enteritis caused by rotavirus or bacterial infection has a rapid onset, heavy symptoms, often accompanied by fever, mucus in the stool, possibly with pus and blood, pus cells and red blood cells under stool microscopy; while lactose intolerance caused by diarrhea has a slow onset, no fever, paste-like stool, negative microscopy, and positive reducing sugar.
2, cow’s milk protein allergy: especially light cow’s milk protein allergy. The diarrhea stops when the baby is switched to breast milk, while lactose intolerant babies are intolerant to both breast milk and cow’s milk. It is important to note that cow’s milk allergy may coexist with lactose intolerance, and the diarrhea will not stop after switching to breast milk. However, babies with cow’s milk protein allergy have negative stool reducing sugar test, which can help to differentiate the two.
3, infant colic syndrome: occurs in babies under 3 months of age, the cause is unknown, the colic is long, recurrent within 3 months. But the syndrome stool reducing sugar negative.
Seven, how to properly feed lactose intolerant babies
Lactose intolerant babies do not need special treatment if the number of stools is small and does not affect growth and development. If the number of diarrhea, weight gain is slow, you need to adjust the diet. If the acute phase is accompanied by dehydration, the first step should be intravenous or oral fluid supplementation to correct dehydration.
Lactose-free formula (including cow’s milk-based or soy-based lactose-free formula) can be used first, and then, after the diarrhea stops, breastfeeding can be gradually increased to a mixture of breast milk and lactose-free formula, depending on the baby’s tolerance.
Unlike cow’s milk protein allergy, where the symptoms of lactose intolerance are proportional to the amount of lactose ingested and therefore rarely need to be completely removed from the diet, cow’s milk protein allergy is not dose-dependent and even minute amounts of the antigen can cause typical symptoms.
VIII. What alternative foods are available for lactose-intolerant babies
1. Lactose-free formula or fresh milk: Lactose-free formula that replaces lactose with maltose or dextran-like in the composition of infant formula, in which protein, fat and other components still retain the formula composition. Lactose-free fresh milk is made by adding lactase to fresh milk to digest and break down the lactose in the fresh milk before drinking.
2, soy milk: soy-based formula based on special manufacturing called soy formula milk, soy does not contain lactose, protein to soy protein, plus methionine and taurine. This formula soy milk is different from the unspecialized manufacturing of soy milk and soy flour, more suitable for the growth and development of infants, but it should not be taken for a long time.
3, cereal or wheat food: full 3 months after the baby can add cereal or wheat food, diarrhea is not very heavy can be more effective.
4, yogurt: in the fresh milk with lactic acid bacteria fermentation made of yogurt, part of the lactose has been broken down into lactic acid, becoming less lactose products. Yogurt should be stored in 0-10 ℃ environment, and should not exceed 14 days, drinking without heating, but for babies who are not used to cold drinks can be slightly warmed. Undeteriorated yogurt should not have bubbles and yeast smell, and no mold or mildew spots should appear on the surface. There is also lactobacillus milk powder, after adding water to make milk, placed in warm water (40 ℃) for 4-6 hours that becomes yogurt.
Regardless of the food substitution, the general principle is not to reduce the baby’s nutritional needs, when the baby can increase complementary foods, reduce breast milk or cow’s milk diarrhea will gradually stop, the prognosis is good.