# Farm-derived bacteria protect children from allergies

> Live situation record from CLSTR: https://clstr.news/situations/farm-derived-bacteria-protect-children-from-allergies
> Updated: 2026-08-22T11:00:00.000Z. Sources: 11. Developments: 3.

An international research team, led by Professor Markus Ege of the University Hospital LMU Munich and the Helmholtz Institute for Asthma and Allergy Research, has identified specific bacteria that provide a biological explanation for the ‘farm effect’. By analyzing dust samples from the mattresses of over 1,000 children and comparing them with barn dust, researchers identified nine gram-positive bacterial species linked to a lower risk of asthma, hay fever, and atopic dermatitis.

Two species, Romboutsia timonensis and Glutamicibacter arilaitensis, are particularly significant, accounting for approximately two-thirds of the protective effect against asthma and about half of the effect on other allergic conditions. The study, published in NEJM Evidence and validated with cohorts from Germany, France, and Finland, found that these bacteria produce metabolites—including kynurenine, xanthine, alpha-linolenic acid, and stearidonic acid—that, when inhaled, activate receptors in the airway epithelium to dampen inflammatory immune responses.

This discovery refines the ‘hygiene hypothesis’. While the traditional theory suggested general microbial contact strengthens immunity, these findings suggest that specific microbial signals are the primary drivers of immune training. Researchers noted this protective effect is most potent during the first years of life, though they cautioned that air pollution and smoking remain significant risk factors for asthma.

## Timeline

### 2026-08-22: Bacteria identified as key to protecting children from allergies

Researchers have identified nine specific bacteria that protect children from asthma and allergies by modulating the immune system, explaining the biological mechanism behind the rural ‘farm effect’.

3 sources. https://clstr.news/cluster/bacteria-identified-as-key-to-protecting-children-from-allergies

### 2026-08-05: Farm Exposure Shields Children from Asthma and Allergies, Study Finds

Research links farm dust bacteria to lower rates of asthma, hay fever and allergies in children, published in NEJM Evidence.

3 sources. https://clstr.news/cluster/farm-exposure-shields-children-from-asthma-and-allergies-study-finds

### 2026-08-01: Farm-Exposed Children Benefit from Specific Bacteria Reducing Asthma and Allergies

Researchers identified two barn‑derived bacteria, Romboutsia timonensis and Glutamicibacter arilaitensis, that explain most of the protective farm‑effect against asthma and allergies, opening paths for new drug

5 sources. https://clstr.news/cluster/farm-exposed-children-benefit-from-specific-bacteria-reducing-asthma-and-allergies

---
Cite as: Farm-derived bacteria protect children from allergies. CLSTR, https://clstr.news/situations/farm-derived-bacteria-protect-children-from-allergies