The randomized, double-blind study, conducted by researchers at the Norwegian University of Science and Technology (NTNU), compared mothers who drank one glass of probiotic milk a day to women who were given a placebo. Use of the probiotic milk - which the mothers drank beginning at week 36 in their pregnancy up through to three months after birth -- reduced the incidence of eczema by 40 percent in children up to age two, the researchers found. The study is a part of a larger research project at the university called the Prevention of Allergy Among Children in Trondheim, or PACT, an ongoing population-based intervention study in Norway focused on childhood allergy.
Random sample of pregnant women
Researchers followed 415 pregnant women and their children from pregnancy until the children were two years old. The participants were randomly selected among pregnant women in Trondheim - and then randomly divided into two groups, one of which was given milk with probiotics, and the other a placebo milk. Mothers in the study did not know whether they were given the probiotic milk or the placebo milk.
"The taste of both products was similar, and the milk was delivered in unmarked milk cartons. This means that neither the participants in the study or the researchers knew who had received probiotic milk or placebo milk," says NTNU researcher Torbjørn Øien, one of the scientists involved in the study. "We can therefore say with great certainty that it was the probiotic bacteria alone that caused the difference in the incidence of eczema between the two groups."
Eczema incidence lower, or less severe
The children were checked for eczema throughout the period, as well as for asthma and allergy at age two. Afterwards, the incidence of asthma, eczema and allergy was compared in the two groups.
"The results showed that probiotic bacteria reduced the incidence of eczema in children up to age two years by 40 percent. And the kids in ‘probiotics group' who did have eczema, had less severe cases," explains Christian Kvikne Dotterud, a student in the Medical Student Research Programme at the Department of Community Medicine at NTNU.
The study did not show any effect from the probiotic milk on asthma or allergies, however.
More research on allergic diseases
Dotterud and his research colleagues have started a follow-up study of the children to see if they find any preventive effect on allergic diseases, especially asthma, when children have reached six years old.
"Our study is the first to show that certain probiotic bacteria given to the mother during pregnancy and breast-feeding prevents eczema," says Dotterud.
Previous studies have shown that ingestion of some probiotics by children may prevent eczema, but this is the first study to show a preventative effect when the mother alone consumed the probiotics.
Via breast milk
"In Norway, there has been some skepticism about giving infants probiotics. Therefore, it is preferable that mothers take probiotics, not children," he said. Probiotics are generally considered safe for healthy people.
To participate in the study mothers had to have planned to breastfeed their children.
"We believe that probiotic bacteria affects breast milk composition in a positive way," Dotterud said.
The study was sponsored by Tine SA, which produced and distributed the milk used in the study. Tine SA is s Norway's largest producer, distributor and exporter of dairy products, and is a cooperative owned by 15,084 Norwegian dairy farmers. Tine SA had no role in the study designs, data collection or data analysis.
The results of the study have been published in the journal The British Journal of Dermatology. The article is entitled: Probiotics in pregnant women to prevent allergic disease: a randomised, double-blind trial [Epub ahead of print]
Why the increase in asthma and allergies in Norway?
PACT, the Prevention of Allergy Among Children in Trondheim study - was started in 2000 as a primary prevention, controlled study to look at measures that might reduce the increase in the incidence of asthma and allergies that has been recorded in Norway in recent decades.
It is an ongoing population-based intervention study in Norway focused on the impacts on childhood allergy of systematic and structure interventions to reduce tobacco exposure, increase the consumption of n-3 polyunsaturated fatty acids, and reduce indoor dampness.
What are probiotics?
Probiotics are live lactic acid bacteria which can be added to food and drink. In contrast to common lactic acid bacteria used in the acidification of products such as milk and yogurt, probiotic bacteria have the ability to survive through the acidic stomach environment and settle temporarily in the intestine. The probiotic lactic acid bacteria have a natural place in the digestive system, where they strengthen normal intestinal flora and are good for the body.
What kind of probiotic milk did the scientists use?
Researchers used the Norwegian product Biola from Tine SA. There are wide variations in terms of how well the strains in the probiotic products on the market have been documented. Biola contains LGG ®, the probiotic bacteria that are currently the most extensively studied in the world. Biola product used in the study also contains Lactobacillus acidophilus (La-5) and Bifidobacterium lactis (Bb-12). These also have documented health effects, albeit less extensive than LGG ®. There is reason to believe that it is beneficial for your health to consume a variety of bacterial strains with documented efficacy, rather than unilateral influence of only one bacterial strain.
What is LGG ®?
LGG ® (Lactobacillus rhamnosus GG) is the probiotic bacteria strain that has been the most studied and researched in terms of human health effects. It has been shown that LGG ® contributes to good gut function and a stronger defense against unwanted bacteria and viruses in the stomach. At present there are more than 500 published articles on LGG ® in international journals and more than 30 doctoral theses have been completed on LGG's ® effect on health. More than 40 countries in different parts of the world market products with LGG ®.