We found no evidence to support a protective association between perinatal use of probiotics and doctor diagnosed asthma or childhood wheeze .
R and omised controlled trials to date have not yielded sufficient evidence to recommend probiotics for the primary prevention of these disorders .
OBJECTIVE To evaluate the association of probiotic supplementation during pregnancy or infancy with  childhood asthma and wheeze .
Probiotics during weaning reduce the incidence of eczema.
A reduced microbial load early in life has been suggested to be linked to the increasing prevalence of allergic diseases in the industrialized world . Some studies have indicated that probiotics may be effective in the prevention of eczema . In vitro studies indicate that probiotics have immunomodulatory effects . In the present study , we evaluated the effects of feeding Lactobacillus F19 during weaning on the incidence of eczema and Th1/Th2 balance . In a double-blind , placebo-controlled r and omized intervention trial , infants were fed cereals with ( n = 89 ) or without Lactobacillus F19 ( n = 90 ) from 4 to 13 months of age . We assessed the cumulative incidence of eczema at 13 months of age . The ratio of interferon-gamma ( IFN-gamma ) to interleukin 4 ( IL4 ) mRNA expression levels in polyclonally stimulated peripheral blood T cells was used as a proxy for immune balance . Total and specific IgE serum levels were also assessed . The cumulative incidence of eczema at 13 months was 11 % ( 4 - 17 % , 95 % CI ) and 22 % ( 13 - 31 % , 95 % CI ) in the probiotic and placebo groups , respectively ( p < 0.05 ) . The number needed to treat was 9 ( 6.5 - 11.5 , 95 % CI ) . At 13 months of age , the IFN-gamma/IL4 mRNA ratio was higher in the probiotic compared with the placebo group ( p < 0.05 ) . In contrast , there were no differences between groups in serum concentrations of IgE. In summary , feeding Lactobacillus F19 during weaning could be an effective tool in the prevention of early manifestation of allergy , e.g. , eczema . The higher Th1/Th2 ratio in the probiotic compared with the placebo group suggests enhancing effects of Lactobacillus F19 on the T cell-mediated immune response
We found no evidence to support a protective association between perinatal use of probiotics and doctor diagnosed asthma or childhood wheeze .
R and omised controlled trials to date have not yielded sufficient evidence to recommend probiotics for the primary prevention of these disorders .
OBJECTIVE To evaluate the association of probiotic supplementation during pregnancy or infancy with  childhood asthma and wheeze .