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 .
Effects of feeding probiotics during weaning on infections and antibody responses to diphtheria, tetanus and Hib vaccines.
Microbial exposure is necessary for the development of normal immune function , which has driven the idea of using probiotics for treatment and prevention of  immune-mediated diseases in infancy and childhood . Mounting evidence indicates that probiotics have immunomodulatory effects . However , the mechanisms are still poorly understood . Specific antibody response is a valuable proxy for immune system maturation status in infancy . We aim ed at determining the impact of Lactobacillus F19 ( LF19 ) during weaning on infections and IgG antibody responses to routine vaccines . In a double-blind , placebo-controlled r and omized intervention trial , infants were fed cereals with ( n = 89 ) or without LF19 ( n = 90 ) from 4 to 13 months of age . Infants were immunized with DTaP ( diphtheria and tetanus toxoid and acellular pertussis ) , polio and Hib-conjugate vaccines at ( 3 ) , 5(1/2 ) and 12 months of age . We assessed the number of days with infections , antibiotic prescriptions and antibody concentrations to Hib capsular polysaccharide ( HibPS ) , diphtheria toxin ( D ) and tetanus toxoid ( T ) before and after the second and third doses . Days with infectious symptoms did not differ between the groups . Days with antibiotic prescriptions were fewer in the LF19 group ( p = 0.044 ) . LF19 enhanced anti-D concentrations when adjusting for breastfeeding duration and colonization with LF19 ( p = 0.024 ) . There was an interaction of the intervention and colonization with LF19 on anti-T concentrations during the course of vaccination ( p = 0.035 ) . The anti-HibPS concentrations were higher after the first and second dose of Hib vaccine in infants breastfed < 6 months compared with those breastfed > or = 6 months ( p < 0.05 ) , with no effect by LF19 . In conclusion , feeding LF19 did not prevent infections , but increased the capacity to raise immune responses to protein antigens , with more pronounced effects in infants breastfed < 6 months
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 .