What Is Allergic Disease?

Allergic diseases are a type of immune problem. They include asthma (affecting the lungs), allergic rhinitis/hay fever (affecting the nose area), eczema (affecting the skin), and also allergies to foods, insects (such as bee stings), and medicines.

Allergic diseases are some of the most common health problems for children, even though they are not spreadable from person to person. At the moment, about 1 in every 3 children experience an allergic disease. Unfortunately allergic diseases are becoming more common in children all around the world.

What Causes Allergic Diseases?

It is agreed that there are many causes of allergic diseases. These causes include genetics, diet, medicines (such as antibiotic use), and environment problems (such as air pollution or mold in the home). There is some proof that environment problems may affect a baby before it is born (for example, when a pregnant mother breathes polluted air).

What Is the Microbiome?

The microbiome is the name for tiny organisms that live together. These include bacteria, fungi and viruses. Microbiomes are a good thing, and exist naturally in the environment. Microbiomes also exist on our skin and inside our body (such as in the gut) and are sometimes called “good bacteria”. Our microbiome helps to keep our body healthy. Even unborn babies have a microbiome. In fact, research has shown that the “contents” of the microbiome in unborn babies may affect their immunity after they are born.

What Are Probiotics?

Probiotics are supplements (e.g., pills, capsules, liquids) or foods (e.g., some yoghurts and fermented cabbage) that contain live “good” bacteria, like those that are found in the body’s natural microbiome. The probiotics used for the research in this paper contained bacteria from groups called Lactobacillus rhamnosus GG and Bifidobacterium lactis BB12.

Why Take Probiotics during Pregnancy?

Some scientists have suggested the idea that, if a mother takes probiotic supplements when pregnant, this could have a good effect on the baby’s microbiota, which could then help prevent the baby having an allergic disease once born. At the moment, the World Allergy Organization (WAO) recommends this for pregnant women who have a high chance of their baby having an allergic disease.

What Do Researchers Already Know about Taking Probiotics during Pregnancy?

The researchers report that there is a knowledge gap about taking probiotics during pregnancy. This means that there is not enough research to be sure about the positive effects, or to know the details needed for treatment (such as how much to take). The researchers identified an opportunity to explore this theme further.

What Questions Did the Researchers Ask?

Previously, the researchers had studied a group of pregnant women taking probiotics to see if the probiotics reduced the development of a pregnancy complication known as gestational diabetes mellitus. This previous study divided the pregnant women into two groups. One group of women took probiotics and the second group did not (known as placebo). As is normal for this type of research, none of the women knew if they were taking a “real” probiotic supplement or a “fake”, so that psychological factors did not affect the results.1 The babies born to these women had grown up and were between 3 and 7 years old. The researchers could now study information about the children’s health and look for a connection with their mothers taking probiotic supplements or placebo.

How Did They Answer These Questions?

The researchers collected information on the children using internationally accepted scientific ways. They gained permission from the mothers and sent questionnaires to find out about the children’s health. The researchers received information about 107 children (no multiple births such as twins were included in the study).

What Did the Researchers Look for?

The researchers used scientific techniques to look for differences between the children whose mothers took probiotics, and the children whose mothers took no probiotics. They examined information about problems with allergic disease, frequency of other illnesses and hospital visits, and also problems such as autism spectrum disorder (ASD) and attention disorders (ADHD).

What Did the Researchers Find out?

The researchers found no differences between the children whose mothers took probiotics and those whose mothers took no probiotics.

Next Steps

Since this study looked at women who had a low chance of their baby having an allergic disease, the researchers identified that it is important to do further studies on women who have a high chance of their baby having an allergic disease. It is possible that a difference may be found for these women and babies.

Also, they state that studies with a larger number of women need to be done, in order to give stronger results. Similarly, they recommend that future research should aim to explore aspects such as the amount of probiotic taken, and at what stage of pregnancy.

¹In the initial study it was concluded that probiotic use during pregnancy did not prevent gestational diabetes mellitus.