Symposium AWWA: 'We have an enormous harvest now'

With a great sense of fulfillment, we look back on an inspiring symposium held in March. To mark six years of AWWA, researchers from around the world gathered in Leiden, to share the latest insights with one another. 

Take a look at the key takeaways of six years of international research on the prevention of asthma and allergies. Featuring Hermelijn Smits, Sejal Saglani, Erika von Mutius, Ben Marsland, Gerard Koppelman and Aki Sinkkonen.

Which mechanisms are important for preventing asthma in children?

Through studies on farm milk, farm dust, and worm-derived molecules, the AWWA consortium has gained new insights.

• Drinking minimally processed cow’s milk (MPM) is associated with fewer infections (such as rhinitis) in early childhood among children born before the COVID-19 pandemic. Infections of the nasal mucosa, such as rhinitis, are a risk factor for developing lower respiratory tract infections and possibly asthma later in life. Although the study — partly due to the pandemic — was not large enough to draw definitive conclusions, it showed that children who consumed MPM developed more antibodies against cow’s milk without developing a cow’s milk allergy. Generally, children who drank more milk experienced healthier development of their gut microbiome.
   
• Certain metabolites produced by gut bacteria appear promising in combating allergic asthma in mouse models. These metabolites suppress severe inflammation in the lungs. Whether these metabolites can be developed into dietary supplements for people with asthma is being further investigated through the start-up Atopius Health.
   
• Epidemiological studies have shown that farm dust has a protective effect against asthma. This protective effect may be linked to bacteria found in cow poo. AWWA investigated this further. These bacteria produce metabolites that become airborne in cow barns as aerosols and have been found in farm dust. When children inhale these particles, they bind to receptors in the airways that may help reduce severe inflammation.
   
• In laboratory studies, exposure to farm dust has been shown to alter the immune system of test animals. Farm dust acts as a natural ‘checkpoint inhibitor’ and raises the threshold for initiating inflammatory processes, which means that inflammation occurs less readily and severely. Additionally, farm dust inhibits processes in the lung epithelial cells that are important in asthma, such as mucus production and the release of so-called ‘alarmins’ (substances that initiate an inflammatory response).
   
• These inflammatory processes are also associated with a specific asthma gene variant (on chromosome 17q21), which increases the risk of asthma. However, children with this same gene variant who grow up on a farm actually have a lower risk of developing asthma. This apparent paradox can be explained by the effects of farm dust on the activity of this risk gene.
   
• The way in which parasitic worms manipulate our immune system offers new clues for preventing asthma. Some substances secreted by the worms block inflammatory responses by our immune system, thereby reducing the likelihood of an asthma attack or viral respiratory infection. Other substances enhance the immune system’s suppressive functions. These compounds have unique properties that allow them to bind to specific cells or matrix structures. These properties can be harnessed for cell-specific and/or tissue-specific therapies.