Lactose intolerance in babies is characterized by an inability to properly digest the milk sugar lactose. Babies with lactose intolerance are born without the enzyme lactase, which is necessary to break down lactose into simple sugars that the body can digest. This type of lactose intolerance, which is called congenital lactose intolerance, is rare.
Physiology
The small intestine is lined with small finger-like projections called villi. Normally, these villi produce the enzymes, including lactase, that are needed to digest various types of foods. Lactase attaches to lactose in the digestive tract and breaks it down into glucose and galactose, which the body can successfully absorb. If a baby does not produce lactase, lactose moves through the digestive system in its full form. When it reaches the bacteria in a baby's large intestine, the bacteria feed on it and produce gas as a result. The gas produced by bacteria is responsible for the symptoms of lactose intolerance.
Babies with congenital lactose intolerance are born without the ability to produce lactase. The condition is autosomal recessive, which means that both the mother and father must pass down the defective gene for the baby to be affected by the condition. Premature babies are most likely to be born with lactose intolerance because the ability to produce the enzyme increases during the third trimester, according to MayoClinic.com.
Symptoms
A baby will generally experience the symptoms of lactose intolerance 30 minutes to two hours after consuming lactose. A baby will not be able to tolerate the lactose in breast milk and will experience diarrhea from birth, according to MayoClinic.com. Other possible symptoms of congenital lactose intolerance include abdominal bloating, gas and vomiting.
Treatment
Congenital lactose intolerance cannot be cured. Treatment focuses on removing lactose from the diet to prevent the development of symptoms. Babies with congenital lactose intolerance must be given a lactose-free formula immediately after birth. These babies will have to avoid foods that contain lactose for the rest of their lives.
Considerations
Lactose intolerance in babies is not the same thing as a milk allergy. A milk allergy involves an abnormal immune system response and can result in a life-threatening allergic reaction. If your baby develops hives, swelling, bloody diarrhea or experiences difficulty breathing, it may indicate an allergy to milk. If you notice any of these signs, contact your health-care provider immediately.
