Scientific studies link farm bacteria and birth order to allergy risks

Recent scientific research has identified specific factors that influence the development of allergies and asthma in children. An international study led by LMU Klinikum and Helmholtz Munich investigated why children raised on livestock farms experience these conditions less frequently. By analyzing data from over 1,000 children across Europe, researchers identified two specific bacteria, ‘Romboutsia timonensis’ and ‘Glutamicibacter arilaitensis’, originating from the digestive systems of cows. These microbes produce substances in stable air that interact with human respiratory receptors, potentially training the immune system to prevent excessive inflammatory reactions.

Complementary research from the United States has examined how birth order affects long-term health. Analyzing medical records from over 10 million people, scientists found that birth order is associated with various health outcomes. First-born children showed higher rates of neurodevelopmental disorders, such as autism and ADHD, as well as asthma and food allergies. Conversely, younger siblings were more frequently diagnosed with migraines, gastritis, and certain joint conditions. Researchers suggest these patterns may result from differences in parental monitoring and early exposure to diverse microbes brought home by older siblings.