OBJECTIVETo assess the preventive effect of probiotics against pediatric allergic diseases.

METHODThe authors searched all randomized controlled trials on the preventive effect of probiotics on pediatric allergic diseases from 8 databases (Pubmed, Medline, Springer link, highwire, Cochrane, Vip, Wanfang Data and CNKI) up to September 2011. Two reviewers assessed the studies to see if they meet inclusion criteria, and extracted data. Meta-analysis for the result of homogenous studies was made with RevMan 4.2 and the co-effect was pooled by using fixed-effects model of relative risk (RR) ratios.

RESULTFifteen studies published between April 2001 and September 2011 including 3604 cases were included. All included studies were graded on randomization, allocation concealment, blinding, baseline and loss to follow-up. Meta-analysis based on included studies showed that prenatal and postnatal probiotic supplementation had preventive effect on pediatric atopic eczema by reducing the RR to 0.78 (95%CI: 0.70 - 0.88, P < 0.0001), and 3 studies in which probiotic was given only after birth, the RR was further reduced to 0.75 (95%CI: 0.66 - 0.86, P < 0.0001). Meta analysis for the effect of lactobacilus alone and combined with other bacteria showed that both decreased the RR ratios of 0.57 (95%CI: 0.44 - 0.73, P < 0.0001) and 0.79 (95%CI: 0.64 - 0.97, P = 0.02), respectively.

CONCLUSIONPresent evidences show that prenatal and postnatal probiotic supplementation will prevent pediatric atopic eczema, but not other allergic diseases such as sensitization, food allergy and asthma.