True lactase deficiency is rare, but transient lactose intolerance is very common in babies, especially after episodes of gastroenteritis or after an infection or allergy or disease that damages the intestine. Precautions should then be taken for the intestinal mucosa to heal and for the lactase to become effective again.

Lactose intolerance corresponds to a problem of digestion of the sugar contained in milk (lactose) and its derivatives. It is linked to insufficient secretion of lactase, the famous enzyme that helps digest lactose in the intestine. Lactose, not transformed by lactase, is found in the intestine where it ferments. This leads to uncomfortable digestive symptoms.

Thus, unlike allergy, intolerance does not involve the immune system: the organism does not defend itself against a substance that it does not support. The reaction is purely metabolic. If you or your partner is lactose intolerant, then there is no need to worry about your child: lactose intolerance is not passed on – unless lactase insufficiency is hereditary – and cases of lactose intolerance in newborns are extremely rare. This disorder generally appears around 2-3 years: the child complains of discomfort after drinking a large amount of milk, in the morning for example.

In case of lactose intolerance, the symptoms closely resemble those of allergy but are limited to the gastrointestinal tract:

• Bloating (swollen belly)
• Abdominal pain
• Stomach cramps
• Gas

In the most severe forms, the child may suffer from particularly irritating diarrhea and vomiting.

The intensity and duration of symptoms depends on the amount of milk ingested since they are due to the fermentation of lactose in the digestive tract.

In congenital lactase deficiency, an inherited disease, symptoms begin within the first few days after birth with watery stools which are often accompanied by vomiting. The newborn does not gain enough weight. This constitutes a larger metabolic disease that requires prompt management.

However, it should be noted that there are transient forms of lactose intolerance. Indeed, certain situations modify the production of lactase such as when the child contracts gastroenteritis, a parasite infection or an allergic reaction which occasionally damages the intestine. Intolerance can then last from a few days to a few months. Celiac disease is of course also the cause of lactose intolerance in many cases.

If you have any doubts about your child, talk to a doctor about their symptoms. Although he cannot make a diagnosis on the spot, he will ask you several questions about his diet if he suspects lactose intolerance. In this case, he will take the opportunity to make appropriate recommendations regarding what to do while waiting for the results, namely:

• changes to make to your child’s diet to meet his nutritional needs while taking into account his possible lactose intolerance
• how much milk and other dairy products your child can eat without feeling unwell
• key words to look for on food labels to identify any presence of milk.

Note that often there is no need to make a more precise diagnosis with laboratory tests or to consider drug treatments based on synthetic lactase. Unless the lactose intolerance is very severe and the very strong symptoms do not improve despite the adaptation of the diet. In this case, you will be advised to refer you to a gastroenterologist, possibly specialized in pediatrics.

If the intolerance occurs as a result of an infection from gastroenteritis, celiac disease, parasite infection or an allergic reaction for example, it will disappear with the recovery of the child. . The milk will then be reintroduced gradually over several weeks so that the lactase activity slowly resumes.

On the other hand, if lactose intolerance is proven, the doctor will help you determine the dose of milk that your child is able to take per day according to the severity of the symptoms that he presents. Unless the intolerance is really very strong, health professionals are generally very reluctant to products labeled “lactose free” or “lactose free”, more and more in fashion. The idea is simply to adapt the meals of the child to this particular sensitivity that he presents. Adapt the dose of milk and its derivatives and not completely escape lactose : such is the rule!

Note that the digestive tolerance of lactose is higher when milk or dairy product is combined with other foods. So avoid offering isolated milk, yoghurts, fromage blanc, faisselle or small Swiss cheese for example to your child. However, the consumption of yoghurts, both natural and flavored, due to the presence of lactic ferments, would promote the digestion of lactose. They are therefore to be integrated, moderately, during meals.

The matured cheeses (Camembert, Comté, Saint Paulin, bûche de chèvre, Edam, Beaufort, etc.) and the butter are lactose-free. There is therefore no question of depriving yourself of it. Only milk (including powdered milk and fermented milk, called kefir) and fresh cheeses (including faisselle, small Swiss and white cheese) contain lactose. As for butter and cream, they are never eaten alone and in large quantities. They therefore present no risk, except for those with severe lactose intolerance.

However, be careful with all products made from milk or milk derivatives: pancakes, waffles, ice creams, dessert creams, chocolate bars, white or milk chocolate products, etc.

In case of strong intolerance, it is necessary to remind your doctor and report it to your pharmacist because some medicines contain lactose.

In the event of a proven total deficiency, this rare hereditary disease called congenital lactase deficiency, the eviction of milk and all its derivatives is absolutely essential. A gastroenterologist will help you adopt the right reflexes with regard to feeding your baby and give you a list of all the ingredients likely to hide lactose.

To meet the needs of babies and children with intolerance, transient or not, to lactose, the laboratories have formulated infant milk without lactose.

These milks are offered in particular to toddlers who have intestinal disturbances such as diarrhea. As soon as the symptoms improve, the child will gradually return to conventional milk. They are also recommended for babies who suffer from celiac disease or any gastrointestinal infection.

In case of congenital lactase deficiency, which induces hereditary lactose intolerance from birth, the child should be fed only with infant formula without lactose, if he is bottle-fed. If he is breastfed, the mother will of course adapt his diet.

Regarding milk, it is important to note that even in cases of severe lactose intolerance (or allergy to cow’s milk protein), vegetable drinks such as those sold in supermarkets are not suitable for the needs of the infant and are formally discouraged by health professionals because of the risks they present for the baby (significant deficiencies).