A protective effect of Lactobacillus rhamnosus HN001 against eczema in the first 2 years of life persists to age 4 years

Summary Background Using a double blind randomized placebo‐controlled trial ( A ustralian N ew Z ealand C linical T rials R egistry: ACTRN 12607000518460), we have shown that in a high risk birth cohort, maternal supplementation from 35 weeks gestation until 6 months if breastfeeding and infant supplementation until 2 years with Lactobacillus rhamnosus HN 001 ( HN 001) (6 × 10 9 cfu/day) halved the cumulative prevalence of eczema by age 2 years. Bifidobacterium animalis subsp lactis HN 019 ( HN 019) (9 × 10 9 cfu/day) had no effect. Objective The aim of this study was to investigate the associations of HN 001 and HN 019 with allergic disease and atopic sensitization among these children at age 4 years, 2 years after stopping probiotic supplementation. Methods The presence ( UK W orking P arty's D iagnostic C riteria) and severity SCOR ing A topic D ermatitis ( SCORAD ) of eczema and atopy (skin prick tests) and parent‐reported symptoms of asthma and rhinoconjunctivitis were assessed using standard protocols and questions. Results Four‐hundred and seventy‐four infants were eligible at birth of whom 425 (90%) participated in this follow‐up. The cumulative prevalence of eczema by 4 years (Hazard ratio ( HR ) 0.57 (95% CI 0.39–0.83)) and prevalence of rhinoconjunctivitis at 4 years (Relative risk 0.38 (95% CI 0.18–0.83)) were significantly reduced in the children taking HN 001; there were also nonsignificant reductions in the cumulative prevalence of SCORAD ≥ 10 ( HR 0.74 (95% CI 0.52–1.05), wheeze ( HR 0.79 (95% CI 0.59–1.07)) and atopic sensitization ( HR = 0.72 (95% CI 0.48–1.06)). HN 019 did not affect the prevalence of any outcome. Conclusions and Clinical Relevance This study showed that the protective effect of HN 001 against eczema, when given for the first 2 years of life only, extended to at least 4 years of age. This, together with our findings for a protective effect against rhinoconjunctivitis, suggests that this probiotic might be an appropriate preventative intervention for high risk infants.