RESUMO
BACKGROUND: Ingestion of prebiotics during pregnancy and lactation may have immunomodulatory benefits for the developing fetal and infant immune system and provide a potential dietary strategy to reduce the risk of allergic diseases. OBJECTIVE: The aim of this trial was to determine whether maternal supplementation with dietary prebiotics reduces the risk of allergic outcomes in infants with hereditary risk. METHODS: We undertook a double-blind, randomized controlled trial in which pregnant women were allocated to consume prebiotics (14.2g daily of galacto-oligosaccharides and fructo-oligosaccharides in ratio 9:1) or placebo (8.7g daily maltodextrin) powder from <21 weeks gestation until 6-months postnatal during lactation. Eligible women had infants with a first-degree relative with a history of medically diagnosed allergic disease. The primary outcome was infant medically diagnosed eczema by 1-year of age, and secondary outcomes included allergen sensitization, food allergy, and recurrent wheeze by 1-year of age. RESULTS: 652 women were randomized between June 2016 and November 2021 (n=329 prebiotics, n=323 placebo). There was no significant difference between groups in the percentage of infants with medically diagnosed eczema by 1-year of age (prebiotics 31.5% (103/327 infants) compared to placebo 32.6% (105/322 infants); adjusted relative risk 0.98 (95% CI 0.77, 1.23; p=0.84). Secondary outcomes and safety measures also did not significantly differ between groups. CONCLUSION: We found little evidence that maternal prebiotics supplementation during pregnancy and lactation reduces the risk of infant medically diagnosed eczema by 1-year of age in infants who are at hereditary risk of allergic disease.