When babies go to the doctor for diarrhea, they are often advised to switch to “diarrhoea milk powder”. Diarrhea milk powders are generally more expensive. What are they used for? Is it necessary to replace it? Before answering these questions, we need to understand lactose and lactose intolerance.

The main difference between diarrhea milk powder and ordinary milk powder is that it is low in lactose or contains no lactose. Lactose is a disaccharide found in milk. Whether it is breast milk, cow’s milk or other animal milk, it contains lactose. After milk is drunk, lactose will be digested into glucose and galactose by lactase secreted by the small intestine, and then absorbed into the blood to provide energy for the body.

Mammals mainly drink milk during infancy and early childhood, so lactase is relatively abundant in infants and young children. As age increases, milk gradually ceases to be the main food, and the secretion of lactase will also decrease. Some people will develop lactase deficiency. If the lactose in milk is not enough to be digested, the undigested lactose will be degraded by intestinal bacteria, producing metabolites such as gas and lactic acid, causing symptoms such as diarrhea, flatulence, and stomach pain. This is lactose intolerance.

Lactose intolerance that gradually develops with age is called primary lactose intolerance. The occurrence of primary lactose intolerance has obvious racial differences, and most of us Chinese have it. However, primary lactose intolerance only occurs in older children and adults. Regardless of race, primary lactose intolerance does not occur before the age of 2-3.

When an infection occurs in the intestine, such as rotavirus enteritis, it will lead to the shedding of the villous epithelial cells in the small intestine, and the newly produced epithelial cells have insufficient ability to synthesize lactase, which may also lead to lactose intolerance. Lactose intolerance that occurs due to disease is called secondary lactose intolerance.

After developing lactose intolerance, if you continue to drink lactose-containing milk, diarrhea symptoms may worsen or last longer. Based on this consideration, doctors may recommend that children with diarrhea switch to lactose-free “diarrhea milk powder.”

Does that mean that when a child has diarrhea, it is recommended to adopt a lactose-free diet? Not really.

For breastfed children, there is strong evidence that breastfeeding can reduce the morbidity and mortality of diarrhea. Therefore, for breastfed children with diarrhea, current domestic and foreign guidelines unanimously believe that breastfeeding should continue to be maintained or increased. Breastfeeding, there is no need to switch to regular formula or lactose-free food.

Although there is some debate about formula-fed children, most authoritative medical institutions still believe that it is not necessary to routinely switch to lactose-free milk powder.

The World Health Organization has always recommended that children with acute diarrhea continue to feed as usual, and emphasizes that the special formulas advertised for children with diarrhea are expensive and unnecessary and should not be consumed routinely. Clinically significant milk intolerance is rare. See.

The American Academy of Pediatrics guidelines believe that although diarrhea may affect lactase secretion, most of it will not cause clinical symptoms or affect absorption. Therefore, it is also recommended that children with diarrhea eat a normal diet for their age, including dairy products containing lactose. No strict restrictions are required. Canadian guidelines also believe that giving lactose-free milk powder is not necessary.

It has been a long time since the diarrhea guidelines from the WHO, the United States and Canada were released. Are their views outdated?

A 2013 Cochrane review summarized the research on the impact of lactose-free diet on diarrhea. It was believed that using a lactose-free diet can shorten the duration of diarrhea in children by about 18 hours, and can also reduce the number of children who fail treatment (no improvement in diarrhea or vomiting symptoms). The chance is reduced by half.

However, these studies come from countries with different income levels, and most of them are studies on hospitalized children with relatively severe conditions. They are not universally applicable, and they are not double-blind studies, so the credibility of the conclusions is not so high. Canadian doctors don’t think it’s enough to change the previous guideline recommendations.

After this Cochrane review came out, the WHO, the United States, and Canada did not issue new guideline recommendations. In 2014, Europe issued a new acute gastroenteritis guideline [8], which also mentioned the Cochrane review. , but still clearly stated that “the routine use of lactose-free milk powder in outpatient clinics is currently not recommended.”

In general, the current common view is that diarrhea may affect the secretion of lactase, but secondary lactose intolerance is rare, so diarrhea does not require a routine lactose-free diet, especially for outpatients who are not seriously ill. , so the current clinical guidelines in most countries do not recommend routine replacement of lactose-free milk powder. However, hospitalized patients or those with long-lasting diarrhea can switch to a lactose-free diet. For example, WHO recommends switching to a lactose-free diet if diarrhea lasts for more than 2 weeks and symptoms do not improve with a normal diet.

Most countries believe that it is not necessary to switch to lactose-free milk powder for diarrhea, but my country is another exception. In 2016, the “Chinese Journal of Pediatrics” published the “Clinical Practice Guidelines for Acute Infectious Diarrhea in Chinese Children”, which states: “Formula feeders can choose to use low-lactose or lactose-free formulas.” This is equivalent to saying that as long as diarrhea is Change to milk powder for diarrhea.

The first time I saw this guide, I was curious about the reason for its recommendation, and then I checked the basis for its views. The referenced document was an article titled “Clinical study on infantile lactose intolerance”. I thought it was a foreign research paper, so I went to Pubmed to search, but I couldn’t find it. Then I translated the title into Chinese, and then searched it in the Chinese database. It turned out to be a Chinese review on lactose intolerance.

This review did not find any evidence to support the routine use of lactose-free formula for children with diarrhea. I don’t know how these clinical guidelines, which represent the highest academic level of Chinese pediatrics, were formulated.