Probiotic supplementation during pregnancy and then for the infants after birth could reduce the incidence of eczema, suggests a new clinical trial from Sweden.
The study, published in the current issue of the Journal of Allergy and Clinical Immunology, reports that, while no significant preventative effect was observed in eczema among all the infants, probiotic-supplemented children of mothers with allergies did experience significant reductions in eczema.
"Although a preventive effect of probiotics on infant eczema was not confirmed, the treated infants had less IgE-associated eczema at 2 years of age and therefore possibly run a reduced risk to develop later respiratory allergic disease," wrote lead author Thomas Abrahamsson from Linkoping University Hospital.
Eczema, also known as atopic dermatitis (AD), is one of the first signs of allergy during the early days of life and is said to be due to delayed development of the immune system. According to the American Academy of Dermatologists it affects between 10 to 20 percent of all infants, but almost half of these kids will 'grow out' of eczema between the ages of five and 15.
The research appears to be in line with a previous study from Finland that reported in 2003 that children who were exposed to the Lactobacillus rhamnosus GG (LGG) bacteria around the time of birth were 40 per cent less likely to develop atopic eczema at four years of age compared with children in a placebo group.
The new double-blind, randomised, placebo-controlled trial included 188 families with allergic disease. Mothers were assigned to receive daily supplements of Lactobacillus reuteri (BioGaia, 100 million colony forming units) or placebo from gestational week 36 until the birth of the child. After this point, the infants were then supplemented with the same product for the first 12 months of their lives, and followed until age 24 months.
The incidence of eczema was similar between the two groups, reported Abrahamsson (approximately 35 per cent). The L. reuteri-supplemented group however had less IgE-associated eczema during the second year, eight versus 20 per cent, respectively.
Immunoglobulin E (IgE) is the predominant antibody associated with an allergic response.
Reactivity of the children towards skin prick tests, a common test for allergy, was also less common in the probiotic-supplemented group, and significantly for children of allergy-suffering mothers - 14 versus 31 per cent, respectively.
"Proposed modes of action by probiotics include improved intestinal barrier function, degradation of macromolecules, and influence on the gut immune system," wrote the authors.
"Earlier studies on the effect of lactobacilli on immune cells in animal or in vitro models have shown promotion of Th1-like responses with IFN-gamma, IL-12, and IL-18 activation, which inhibits development of a Th2-like deviation in infants.
"L. reuteri has displayed a slightly different profile than other probiotic bacteria and seems to possess more pronounced anti-inflammatory properties, as demonstrated in animal and human in vitro studies," they said.
"As sensitized infants with eczema have increased risk for later development of allergic asthma and rhinoconjunctivitis, studies on the outcome in older children, as well as possible mechanisms behind this effect, are warranted," they concluded.
Source: Journal of Allergy and Clinical Immunology (Elsevier)
Volume 119, Issue 5, Pages 1174-1180
"Probiotics in prevention of IgE-associated eczema: A double-blind, randomized, placebo-controlled trial"
Authors: T.R. Abrahamsson, T. Jakobsson, M. Fageras Bottcher, M. Fredrikson, M.C. Jenmalm, B. Bjorksten and G. Oldaeus