Lactobacillus rhamnosus HN001 and Reduced Prevalence of Atopic Sensitization

Research synthesisLow evidenceSmall effect3 studies · 0 beneficial · 3 neutral · 0 harmful

Across 3 randomized controlled trials, all reported neutral small effects of Lactobacillus rhamnosus HN001 on reduced prevalence of atopic sensitization, with no statistically significant findings. The most-studied dose was 6 × 10^9 CFU daily, given to mothers and/or infants from gestation through early childhood. Evidence base is small (only 3 studies) — conclusions should be considered preliminary.

Effective dose range: 6 × 10^9 CFU daily
Studied populations: pregnant and breastfeeding mothers and their infants, high-risk birth cohort

Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. None of the included studies reached statistical significance; effect may be smaller than the predominant direction suggests.

Generated Jun 11, 2026

Doses used in studies

CFU/day: 6 billion (median 6 billion, IQR 6 billion–6 billion) — 3 studies

Safety in these studies

Overall tolerabilityReported
This study showed that the protective effect of HN001 against eczema... extended to at least 4 years of age.
from: A protective effect of Lactobacillus rhamnosus HN001 against eczema in the first 2 years o

3 of 3 papersPopulation:

Effects of Lactobacillus rhamnosus HN001 in early life on the cumulative prevalence of allergic disease to 11 years
- 2018-11-14
- RCT
- Pediatric Allergy and Immunology 29(8)
- - K. Wickens
  - C. Barthow
  - E. Mitchell
  - Janice Kang
  - N. van Zyl
  - G. Purdie
  - T. Stanley
  - P. Fitzharris
  - R. Murphy
  - J. Crane
- PubMed: 30430649
- DOI: 10.1111/pai.12982
10 Insights on
- Reduced Prevalence of Atopic Sensitization
- High evidence
- Rigorous Journal
- Mixed
HN019 had no significant effect on these outcomes
Effect
Neutral
Effect size
Small
Significant
No
Dose
9 × 10^9 cfu daily from 35-week gestation to 6 months' post-partum in mothers while breastfeeding and from birth to age 2 years in infants
Maternal supplementation alone with Lactobacillus rhamnosus HN001 during pregnancy and breastfeeding does not reduce infant eczema
- 2018-04-06
- RCT
- Pediatric Allergy and Immunology 29(3)
- - K. Wickens
  - C. Barthow
  - E. Mitchell
  - T. Stanley
  - G. Purdie
  - Judy Rowden
  - Janice Kang
  - Fiona Hood
  - L. V. D. van den Elsen
  - Elizabeth E Forbes-Blom
  - I. Franklin
  - Phillipa Barnes
  - P. Fitzharris
  - Robyn M. Maude
  - P. Stone
  - P. Abels
  - R. Murphy
  - J. Crane
- PubMed: 29415330
- DOI: 10.1111/pai.12874
7 Insights on
- Reduced Prevalence of Atopic Sensitization
- High evidence
- Rigorous Journal
- Mixed
Maternal-only HN001 supplementation did not significantly reduce ... atopic sensitization in the infant by 12 months
Effect
Neutral
Effect size
Small
Significant
No
Dose
6 × 10^9 colony-forming units daily
A protective effect of Lactobacillus rhamnosus HN001 against eczema in the first 2 years of life persists to age 4 years
- 2012-06-15
- RCT
- Clinical & Experimental Allergy 42(7)
- - K. Wickens
  - Peter N. Black
  - Thorsten Stanley
  - Edwin A. Mitchell
  - C. Barthow
  - P. Fitzharris
  - Gordon Purdie
  - Julian Crane
- PubMed: 22702506
- DOI: 10.1111/j.1365-2222.2012.03975.x
6 Insights on
- Reduced Prevalence of Atopic Sensitization
- High evidence
- Highly Cited
atopic sensitization (HR = 0.72 (95% CI 0.48-1.06))
Effect
Neutral
Effect size
Small
Significant
No
Dose
6 × 10^9 cfu/day

Lactobacillus rhamnosus HN001 and Reduced Prevalence of Atopic Sensitization

Effects of Lactobacillus rhamnosus HN001 in early life on the cumulative prevalence of allergic disease to 11 years

Maternal supplementation alone with Lactobacillus rhamnosus HN001 during pregnancy and breastfeeding does not reduce infant eczema

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