Abstract
Background In a two-centre randomized placebo-controlled trial of Lactobacillus rhamnosus HN001 (HN001) (6 x 10(9) colony-forming units [cfu]) or Bifidobacterium lactis HN019 (HN019) (9 x 10(9) cfu) taken daily from 35-week gestation to 6 months' post-partum in mothers while breastfeeding and from birth to age 2 years in infants, we showed that HN001 significantly protected against eczema development at 2, 4 and 6 years and atopic sensitization at 6 years. There was no effect of HN019. We report here the findings for 11 year outcomes. Methods At age 11 years, eczema was defined as previously using the UK Working Party's Diagnostic Criteria. Asthma, wheeze, hay fever and rhinitis were defined based on the International Study of Asthma and Allergies in Childhood (ISAAC) questions. Atopic sensitization was defined as one or more positive responses (mean wheal diameter >= 3 mm) to a panel of food and aeroallergens. Analysis was intention-to-treat using hazard ratios to assess probiotic effects on the 11-year lifetime prevalence and relative risks for point or 12-month prevalence at 11 years. Results Early childhood HN001 supplementation was associated with significant reductions in the 12-month prevalence of eczema at age 11 years (relative risk [RR] = 0.46, 95% CI 0.25-0.86, P = 0.015) and hay fever (RR = 0.73, 95% CI 0.53-1.00, P = 0.047). For the lifetime prevalence, HN001 was associated with a significant reduction in atopic sensitization (hazard ratio [HR] = 0.71, 95% CI 0.51-1.00, P = 0.048), eczema (HR = 0.58, 95% CI 0.41-0.82, P = 0.002) and wheeze (HR = 0.76, 95% CI 0.57-0.99, P = 0.046). HN019 had no significant effect on these outcomes. Conclusion This is the first early probiotic intervention to show positive outcomes for at least the first decade of life across the spectrum of allergic disease.