High to moderate certainty in the body of evidence suggests that LGG supplementation ( regardless of the timing of administration ) did not reduce the risk of eczema .
There was also no consistent effect on other allergic outcomes .
This meta- analysis shows that LGG was ineffective in reducing eczema .
Current guidelines recommend the use of probiotics to reduce the risk of  eczema .
It remains unclear which strain(s ) to use .
We systematic ally evaluated data on the efficacy of Lactobacillus rhamnosus GG ( LGG ) supplementation prenatally and /or postnatally for the primary prevention of eczema .
World Allergy Organization-McMaster University Guidelines for Allergic Disease Prevention (GLAD-P): Probiotics
Background Prevalence of  allergic diseases in infants , whose parents and siblings do not have allergy , is approximately 10 % and reaches 20–30 % in those with an allergic first-degree relative . Intestinal microbiota may modulate immunologic and inflammatory systemic responses and , thus , influence development of sensitization and allergy . Probiotics have been reported to modulate immune responses and their supplementation has been proposed as a preventive intervention . Objective The World Allergy Organization ( WAO ) convened a guideline panel to develop evidence -based recommendations about the use of probiotics in the prevention of allergy . Methods We identified the most relevant clinical questions and performed a systematic review of r and omized controlled trials of probiotics for the prevention of allergy . We followed the Grading of Recommendations Assessment , Development and Evaluation ( GRADE ) approach to develop recommendations . We search ed for and review ed the evidence about health effects , patient values and preferences , and re source use ( up to November 2014 ) . We followed the GRADE evidence -to-decision framework to develop recommendations . Results Currently available evidence does not indicate that probiotic supplementation  reduces the risk of developing allergy in children . However , considering all critical outcomes in this context , the WAO guideline panel determined that there is a likely net benefit from using probiotics result ing primarily from prevention of eczema . The WAO guideline panel suggests : a ) using probiotics in pregnant women at high risk for having an allergic child ; b ) using probiotics in women who breastfeed infants at high risk of developing allergy ; and c ) using probiotics in infants at high risk of developing allergy . All recommendations are conditional and supported by very low quality evidence . Conclusions WAO recommendations about probiotic supplementation for prevention of allergy are intended to support parents , clinicians and other health care professionals in their decisions whether to use probiotics in pregnancy and during breastfeeding , and whether to give them to infants
High to moderate certainty in the body of evidence suggests that LGG supplementation ( regardless of the timing of administration ) did not reduce the risk of eczema .
There was also no consistent effect on other allergic outcomes .
This meta- analysis shows that LGG was ineffective in reducing eczema .
Current guidelines recommend the use of probiotics to reduce the risk of  eczema .
It remains unclear which strain(s ) to use .
We systematic ally evaluated data on the efficacy of Lactobacillus rhamnosus GG ( LGG ) supplementation prenatally and /or postnatally for the primary prevention of eczema .