Effect of brewers' yeast or beta-glucan derived from Saccharomyces cerevisiae on breast milk supply following preterm birth: the BLOOM randomised controlled trial
In brief
Brewers' yeast shows no increase in milk volume for preterm mothers
In a trial of 105 mothers of infants born before 34 weeks, a 7-day course of brewers' yeast or beta-glucan did not raise 24-hour expressed breast-milk output compared with placebo (difference ≈ 94 mL/day for yeast, not statistically clear). Both supplements were well tolerated, but larger studies are needed to rule out a modest benefit.
- Journal
- Archives of disease in childhood. Fetal and neonatal edition (Q1)
- Published
- 1 September 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Luke Grzeskowiak, Lauren Williams, Alice Rumbold, Bronni Simpson, Renee L Kam, Lisa Nicole Yelland, et al.
- PMID
- 42680572
- DOI
- 10.1136/archdischild-2025-330214
Why clinicians should know about it
- Picked for Neonatology (top studies of the week, 6 September 2026): Randomised trial of brewers' yeast on breast‑milk volume for preterm
- Picked for Obstetrics and Gynecology (top studies of the week, 6 September 2026): Brewers’ yeast or beta‑glucan effect on breast‑milk supply after preterm
Abstract
OBJECTIVE: Breast milk is the optimal source of nutrition for preterm infants; however, low breast milk production is common following a preterm birth. This study aimed to determine if taking brewers' yeast or beta-glucan improves daily expressed breast milk volume. DESIGN: Randomised, blinded, parallel, placebo-controlled trial. SETTING: Three Australian tertiary-level neonatal units. PATIENTS: Mothers with a singleton or twin pregnancy who gave birth at <34 weeks' gestation. INTERVENTIONS: Mothers were randomised within 72 hours of birth into three parallel groups in a 1:1:1 ratio to receive either brewers' yeast, beta-glucan or placebo capsules for 7 days. MAIN OUTCOME MEASURE: Total expressed breast milk volume over a 24-hour period on day 7 of intervention. RESULTS: A total of 105 mothers underwent randomisation between August 2022 and April 2024 (36 brewers' yeast, 35 beta-glucan and 34 placebo). The adjusted mean difference in daily expressed breast milk volume was 94 mL/day (95% CI -51 mL/day to 239 mL/day) between the brewers' yeast and placebo groups and -25 mL/day (95% CI -173 mL/day to 123 mL/day) between the beta-glucan and placebo groups. Maternal side effects were similar across groups. CONCLUSION: We found no clear effect of short-term administration of brewers' yeast or beta-glucan on breast-milk production following preterm birth; both interventions were well tolerated. Given the small sample size, these findings do not rule out the possibility of a clinically meaningful benefit of brewers' yeast and suggest further research with a larger sample size may be warranted to clarify the potential clinical impact. TRIAL REGISTRATION NUMBER: ACTRN12622000968774.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.