Prebiotics in baby milk may protect against eczema

What do we know already?

Prebiotics are non-digestible substances that encourage the bacteria in our stomachs to grow and help us digest food. They are not to be confused with probiotics, which are live micro-organisms, usually bacteria, that live in our digestive systems and help digestion. The most common types of prebiotics are sugars called fructo-oligosaccharides (FOS), inulin, and galacto-oligosaccharides. They are found naturally in various vegetables and fruits, such as tomatoes, asparagus, and bananas.

Prebiotics are also commonly added to powdered baby milk, as it is thought that they may help make formula milk easier to digest. This is because formula milk is harder for babies to digest than breast milk. There is also some evidence that prebiotics can help some stomach conditions such as colitis.

To find out more, researchers pooled evidence from good-quality studies of the effects of prebiotics added to babies’ milk. They looked at how likely babies were to develop allergic diseases such as asthma, eczema, and hives. These illnesses are all caused by the body’s immune system reacting to allergens (any substance that can cause an allergy), particularly allergens in food.

The researchers looked at four studies that included 1,428 babies aged less than six months old who were fed formula or human milk with or without added prebiotics. They also compared different prebiotic supplements to see if some had more health benefits than others.

What does the new study say?

Babies who had prebiotic supplements added to their milk were less likely than babies who didn’t have prebiotics in their milk to get eczema between the ages of four months and two years. Both types of enriched milk, formula and human, worked equally well at preventing eczema.

There was also some evidence that prebiotics might be more helpful for babies who were at high risk of having allergic reactions. The researchers didn’t find any link between prebiotic supplements and other allergic reactions, such as hives.

How reliable is the research?

This type of review, which pools the results of high-quality studies that have randomly assigned people to have different treatments, and then compares the results, is the best way we have of looking at the effects of treatments.

However, although the studies in this review were generally considered to be good quality, the researchers still had some concerns about the strength of some of the evidence they contained, and about what can be read into them. In particular, they couldn’t be sure whether prebiotics should only be recommended for babies who are thought to be at risk of developing an allergy.

What does this mean for me?

This study suggests that formula milk with added prebiotics may help prevent some children from developing eczema, although there isn’t enough evidence for a general recommendation. Either way, giving your baby formula that contains these kinds of supplements is unlikely to do them any harm. If you are breastfeeding, there’s no need to worry that your baby is missing out on any health benefits, as breast milk contains large amounts of natural prebiotic sugars.