August 19/Minneapolis/HealthDay -- Probiotic exposure in early life may reduce total immunoglobulin E level (IgE) and protect against atopic sensitization, but does not seem to protect against asthma/wheezing, according to a meta-analysis published online August 19 in Pediatrics.

In an effort to assess the effects of probiotic supplementation on atopic sensitization and asthma/wheeze prevention in children, Nancy Elazab, M.D., from the University of Miami, and colleagues used a random-effects model to calculate pooled risk estimates. The effect of factors influencing probiotics efficacy was examined with meta-regression.

The researchers found that probiotics were effective in reducing total IgE (P = 0.044), and the reduction in IgE was more pronounced with longer follow-up. Probiotics significantly reduced the risk of atopic sensitization both when administered prenatally (relative risk, 0.88; P = 0.035 for positive result on the skin prick test and/or elevated specific IgE to common allergens) and when administered postnatally (relative risk, 0.86; P = 0.027 for positive result on skin prick test). There was a significantly increased risk of atopic sensitization with administration of Lactobacillus acidophilus, compared with other strains (P = 0.002). Asthma/wheeze were not significantly reduced with probiotics (relative risk, 0.96; 95 percent confidence interval, 0.85 to 1.07).

"Prenatal and/or early-life probiotic administration reduces the risk of atopic sensitization and decreases the total IgE level in children but may not reduce the risk of asthma/wheeze," the authors write.