Lactase Deficiency in Babies: What It Is and How to Recognise It

During the first months of life, milk is the main part of a baby’s diet, so parents tend to notice even small changes after feeding. Gas, tummy rumbling, bloating, loose stools or fussiness can have many different causes. One of them is lactase deficiency in babies, when the activity of the enzyme needed to break down milk sugar is lower than required. This may be associated with signs commonly described as lactose intolerance in babies.

What Is Lactase Deficiency in Babies?

Lactose is a natural carbohydrate found in breast milk and many types of infant formula. To break it down, the body needs lactase — an enzyme produced in the small intestine. Lactase splits lactose into two simpler sugars: glucose and galactose.

If you would like to understand the difference between these two similar-sounding terms in more detail, read our article “Lactase and Lactose: What Is the Difference and Why Do Babies Need Them?”.

When lactase activity is lower, some lactose may remain undigested and pass into the large intestine. There, intestinal bacteria interact with it, and this process may be accompanied by gas formation and additional fluid in the intestine.

Lactose Intolerance Symptoms in Babies

Lactose intolerance symptoms in babies may become noticeable after breastfeeding or formula feeding. Parents may observe:

• increased gas;
• tummy rumbling and bloating;
• loose or watery stools;
• fussiness during or after feeding.

However, one sign alone does not mean that a baby has lactase deficiency or lactose intolerance. Similar symptoms can have many different causes. It is therefore important to notice whether they repeatedly occur after feeding and to discuss any concerns with a paediatrician.

What Can Cause Lactase Deficiency in Infants?

In most full-term babies, lactase is already actively produced at birth. However, there are situations when the activity of this enzyme may be lower.

An immature digestive system in premature babies. Lactase activity increases during the later stages of fetal development. Babies born prematurely may therefore need more time for lactase activity to develop.

Temporarily reduced lactase activity. This may occur following changes in the lining of the small intestine, as this is where the lactase enzyme is produced.

Congenital lactase deficiency. This is a rare condition in which the body produces very little lactase from birth or produces almost none at all.

It is also worth remembering that lactose itself is a normal component of breast milk. You can read more about this in “Lactose in Breast Milk: What Parents Should Know”.

What parents may notice after feeding	What to pay attention to
Gas and tummy rumbling	Whether it occurs regularly
Abdominal bloating	Whether it is associated with feeding
Loose stools	Whether their frequency or consistency changes
Fussiness	Whether other signs occur at the same time

Mamalac — Lactase Drops for Babies

Mamalac is a dietary supplement in drop form containing a highly active plant-derived lactase enzyme. Lactase is involved in breaking down milk sugar into glucose and galactose.

The drop form is designed for use in infants according to the dosage table. During breastfeeding, the required number of drops can be given to the baby on a spoon before feeding. For formula-fed babies, the drops are added to properly prepared infant formula according to the instructions.

A bottle of Mamalac contains 15 ml of solution, with 3000 ALU of lactase per 1 ml. When 8 drops are used per serving, one bottle provides approximately 37 servings. The enzyme remains active in an acidic environment and across fluctuations in pH.

The number of drops depends on the baby’s age and the volume of breast milk or infant formula, so the dosage table should always be followed. Detailed instructions are available on the Mamalac product page.

FAQ

How can I tell if my baby may have lactase deficiency?

Rather than focusing on a single sign, notice whether certain changes repeatedly appear after feeding. These may include gas, bloating, tummy rumbling, changes in stool consistency or fussiness. The cause of these signs should be assessed by a paediatrician.

What are the symptoms of lactose intolerance in babies?

Possible symptoms of lactose intolerance in babies include bloating, increased gas, tummy rumbling and loose or watery stools after milk feeding. However, similar signs can occur for other reasons as well.

Does breast milk contain lactose?

Yes. Lactose in breast milk is a natural carbohydrate and one of its main sugars.

Are lactose and lactase the same thing?

No. Lactose is milk sugar, while lactase is the enzyme that breaks lactose down into glucose and galactose.

Can newborn babies have lactase deficiency?

Yes, although congenital lactase deficiency is rare. Temporarily lower lactase activity may occur, for example, in babies born prematurely.

What do Mamalac lactase drops contain?

Mamalac contains a plant-derived lactase enzyme. 1 ml of the drop solution contains 3000 ALU of lactase.

How are Mamalac drops used during breastfeeding?

The number of drops is determined according to the dosage table, taking into account the baby’s age and feeding volume. The detailed method of use is provided in the product instructions.

Can Mamalac lactase drops be used with infant formula?

Yes. Mamalac lactase drops for babies can be added to properly prepared infant formula in the amount indicated in the dosage table.

Where can I buy Mamalac?

The Mamalac dietary supplement with lactase enzyme for infants is available through the official Mamalac product page or from the online partner Allegro.pl.

A dietary supplement should not be used as a substitute for a varied and balanced diet.