Long-term effects of probiotics in primary prevention of allergic disease need further evaluation. We previously reported a reduced cumulative incidence of infant eczema by feeding Lactobacillus paracasei ssp paracasei F19 (LF19) during weaning. Therefore, we assessed effects of LF19 on the prevalence of allergic disease at school age.Methods
In a double-blind placebo-controlled trial infants were randomized to daily intake of cereals with (n = 89) or without LF19 108 CFU (n = 90) from 4–13 months of age. At age 8–9, we evaluated the prevalence of allergic disease (eczema, allergic rhinitis, asthma, and food allergy) by clinical examination and validated questionnaires. IgE sensitization was assessed by skin prick test (inhalant allergens) and specific IgE levels (food allergens). Lung function was evaluated by a spirometry reversibility test. Fractional exhaled nitric oxide (FENO) was measured.Results
Of 171 children that completed the intervention, 121 were assessed at age 8–9. In the probiotic group, 15/59 (25%) were diagnosed with any allergic disease vs 22/62 (35%) in the placebo group [OR (95% CI) 0.62 (0.28–1.36)]. Corresponding numbers for IgE-associated allergic disease were 9/53 (17%) vs 12/59 (20%) [0.80 (0.31–2.09)]. Median (25th-75th percentile) FENO was 9 (8–12) in the probiotic vs 8 (7–12) ppb in the placebo group (P > 0.05). There was no effect of LF19 on lung function measures (P > 0.05).Conclusions
There was no long-term effect of LF19 on any diagnosed allergic disease, airway inflammation or IgE sensitization. This suggests delayed eczema onset but to fully examine long-term benefits a larger study population had been needed.