Can Barn Dust Be the Key to Allergy Prevention?

Why do children who grow up on farms develop asthma and allergies less frequently? Researchers at the Dr. von Hauner Children's Hospital of the LMU Klinikum have made a significant step toward understanding how this "protective farm effect" works. The results were recently published in the journal Allergy.

The "Farm Effect" and the Hygiene Hypothesis

The phenomenon of the "farm effect" is based on the established hygiene hypothesis, which suggests that the child’s immune system is trained in the early years of life through regular contact with certain microorganisms. This exposure helps the immune system avoid excessive reactions to harmless substances and promotes a healthy immune balance. Studies have shown that children who grow up in rural environments and have regular contact with barn dust develop asthma significantly less often than their peers from urban areas.

New Insights into Immune Reactions Triggered by Barn Dust

A team led by Prof. Dr. Bianca Schaub, Professor of Pediatric Allergology at LMU and Head of the Asthma & Allergy Disease Area at DZL, conducted a cell culture study to investigate how the immune system responds to barn dust. They demonstrated that in children with manifest asthma, specific cells of the innate immune system were reduced after stimulation with barn dust. At the same time, subpopulations of cells from the acquired immune system, including B cells and certain T-helper cells, increased. These changes indicate a modulation of the immune system that could lead to anti-inflammatory effects.

“We now know that the innate immune system plays a much more central role in allergy development and prevention than we had thought for decades,” says Prof. Schaub. Previous studies had already shown that the protection conferred by barn dust is mediated by anti-inflammatory effects.

Lipocalins in Barn Dust: Protective Proteins

A recently published study involving Prof. Dr. Erika von Mutius, DZL researcher and former board member, as well as Director of the Institute of Asthma and Allergy Prevention at Helmholtz Munich, found that barn dust contains transport proteins called lipocalins, which influence immune function. These molecules are present in particularly high concentrations in barn dust and could play a major role in its protective effects.

Therapeutic Perspectives for Asthma and Allergies

The researchers continue their work with the goal of identifying the specific substances in barn dust that positively influence the immune system. Their long-term aim is to make these beneficial substances accessible to children who do not live in rural areas. “The fact that barn dust stimulation can even modulate immune responses in the laboratory in children with existing asthma potentially opens up new avenues for the treatment of already symptomatic children,” says Prof. Schaub.

This research could eventually help develop innovative therapeutic approaches for the prevention and treatment of asthma and other allergies.

Source: Das Geheimnis des Stallstaubs | LMU Klinikum

Original publication: Beerweiler CC, Salvermoser M, Theodorou J, Böck A, Sattler F, Kulig P, Tosevski V, Schaub B. Farm-dust mediated protection of childhood asthma: Mass cytometry reveals novel cellular regulation. Allergy. 2024 Nov;79(11):3022-3035. doi: 10.1111/all.16347. Epub 2024 Oct 14. PMID: 39400913.