Impact of maternal supplementation with probiotics during pregnancy on atopic eczema in childhood – a meta-analysis

Systematic review and meta-analysis of randomized controlled trials in pregnant women taking probiotics, with childhood atopic eczema or related allergic outcomes assessed in the offspring. The pooled evidence covered seven studies and 2,843 children, with follow-up extending into childhood, including ages 2 to 7 years.

Maternal probiotic supplementation during pregnancy was evaluated, sometimes continuing through delivery, lactation, or early infancy, versus placebo. Regimens were predominantly Lactobacillus-based monotherapy or mixed-strain probiotic combinations, with trial doses ranging from 1 x 10^8 to 1 x 10^10 CFU depending on the strain and study.

Overall, maternal probiotic supplementation appeared to reduce childhood atopic eczema risk, but the benefit was driven by Lactobacillus-based regimens rather than mixed-strain preparations. The clearest trial-level effects were seen with Lactobacillus rhamnosus GG, including RR 0.51 (0.32, 0.84) at 2 years and RR 0.58 (0.35, 0.94) at 7 years. Mixed probiotic strains did not show a significant effect, and there is no evidence-based support for multi-strain probiotics for this indication. Longer-term effects still need further study.

The evidence base was limited by small individual trials, heterogeneous probiotic strains and dosing schedules, and variable timing and duration of supplementation. Effects were not consistent across all formulations, with mixed-strain preparations showing no significant benefit. Longer-term follow-up data were limited, so durability of benefit remains uncertain.