Orally applied bacterial lysate in infants at risk for atopy does not prevent atopic dermatitis, allergic rhinitis, asthma or allergic sensitization at school age: Follow-up of a randomized trial

Allergy. 2020 Aug;75(8):2020-2025. doi: 10.1111/all.14247. Epub 2020 Mar 17.


Background: The allergy preventive effects of gut immune modulation by bacterial compounds are still not fully understood.

Objective: We sought to evaluate the effect of bacterial lysate applied orally from the second until seventh months of life on the prevalence of allergic diseases at school age.

Methods: In a randomized, placebo-controlled trial, 606 newborns with at least one allergic parent received orally a bacterial lysate consisting of heat-killed Gram-negative Escherichia coli Symbio and Gram-positive Enterococcus faecalis Symbio or placebo from week 5 until the end of month 7. A total of 402 children were followed until school age (6-11 years) for the assessment of current atopic dermatitis (AD), allergic rhinitis (AR), asthma and sensitization against aeroallergens.

Results: AD was diagnosed in 11.0% (22/200) of children in the active and in 10.4% (21/202) of children in the placebo group. AR was diagnosed in 35% (70/200) of children in the active and in 38.1% (77/202) children in the placebo group. Asthma was diagnosed in 9% (18/199) of children in the active and in 6.6% (13/197) of children in the placebo group. Sensitization occurred in 46.5% (66/142) of participants in the active and 51.7% (76/147) in the placebo group.

Conclusion: An oral bacterial lysate of heat-killed Gram-negative Escherichia coli and Gram-positive Enterococcus faecalis applied during the first 7 months of life did not influence the development of AD, asthma and AR at school age.

Keywords: asthma; atopic dermatitis; prevention; rhinitis.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Asthma* / epidemiology
  • Asthma* / prevention & control
  • Cell Extracts
  • Child
  • Dermatitis, Atopic* / epidemiology
  • Dermatitis, Atopic* / prevention & control
  • Follow-Up Studies
  • Humans
  • Infant
  • Infant, Newborn
  • Rhinitis, Allergic* / epidemiology
  • Rhinitis, Allergic* / prevention & control
  • Schools


  • Broncho-Vaxom
  • Cell Extracts