There is already some evidence to suggest that probiotic bacteria taken by mothers can reduce the likelihood of eczema, also an allergic disease. For example, in 2003 Finnish researchers demonstrated that children who were exposed to probiotics around the time of birth were 40 per cent less likely to develop atopic eczema at four years of age than children in a placebo group.
However exposure to probiotics did not have any protective effect over asthma in this study.
Yet researchers at Swansea University's School of Medicine, working with the leading UK probiotics maker, Cultech, believe that probiotic bacteria may be able to stimulate the immune response to asthma too.
Both asthma and eczema are associated with abnormal immune responses in the newborn child.
"The immune dysfunction underlying allergy is thought to be caused by inadequate stimulation of the immune system in today's hygienic environment. Studies suggest that such stimulation could be provided by probiotic organisms, and this could help to prevent allergic diseases," explained study leader Dr Steve Allen.
His team will test whether babies taking probiotics every day for the first six months go on to get less allergic disorders than those taking a placebo. They plan to recruit 600 babies into the study, who will be followed-up to the age of five.
Allergic disorders such as eczema, hay fever and asthma are very common in South Wales and are on the rise in many developed countries. In the UK, one in eight children has asthma and this figure has increased six-fold in the last 25 years, according to Asthma UK. This increase is prompting interest in preventative therapies.
Researchers from BioGaia, maker of Reuteri bacteria, and Sweden's Karolinska Institute are also investigating the impact of probiotics on allergies in around 200 mothers and their infants. Half of the mothers received Reuteri supplements for four weeks prior to birth of their babies and these babies are now being given probiotics for their first year.
They recently reported that an analysis of breast milk taken from the mothers in the supplement group a couple of days after giving birth showed increased levels of the anti-inflammatory cytokine (cell signal substance) IL-10 and reduced levels of TGF-beta-2.
The cytokine IL-10 is central to regulation of the immune system and has been shown to have anti-inflammatory properties. Full results of this study are expected in the third quarter of this year.
The Welsh researchers are working with four industrial partners to develop and market suitable products resulting from the research. These include Cultech, Danisco Foods in the USA, Obsidian Research (a small biochemistry-based research organisation) and the supplement marketing firm BioCare.