Growing evidence suggests that getting cozy with soil microbes, especially as kids, can guard against allergic disease. Credit: Jenna Stensland
Researcher contact:
Joshua Ladau, Arva Intelligence, [email protected] (UTC-8 hours)
AGU press contact:
Sean Cummings, [email protected] (UTC-5 hours)
NEW ORLEANS – The unique blend of fungi and bacteria in a region’s soil might potentially be the strongest factor explaining rates of childhood allergic disease. Certain combinations of soil microbes appear linked to better health outcomes, according to new research to be presented at AGU’s 2025 Annual Meeting in New Orleans. While a direct cause-and-effect relationship hasn’t been proven, the researchers say this pattern appears consistently across the globe.
“We’ve analyzed the data in every way we can think of-adding datasets,looking at different measures of soil diversity…but no matter how we’ve done it,this result is consistent,” said Joshua Ladau,a microbial ecologist involved in the research and working at Arva Intelligence,a farmer-focused environmental solutions company. “At this point, I’m exceedingly confident this association is real.”
Ladau will present his research on December 16 at AGU25, joining more than 20,000 scientists discussing the latest Earth and space science research.
A global question
Allergic disease affects an estimated 2.5 billion people worldwide, roughly 30% of humanity. A growing body of research indicates that exposure to diverse soil microbes, especially in childhood, can help limit allergic disease – potentially by helping us develop immune tolerance early in life, experts hypothesize. Though, the extent of this influence compared to othre factors remains unclear.
“When you compare the effects of beneficial microbes with things like access to health care, genetics, climate, and pollution, how do they stack up? That was our question,” Ladau said. “Soils aren’t generally the first thing people consider when thinking about health.”
To investigate, the team used datasets recording the prevalence and severity of atopic dermatitis, asthma, and allergic rhinitis among over a million children in over 250 cities across 97 countries. They also used three global surveys of soil fungal and bacterial diversity, totaling over 8,200 soil samples from around the globe. They then used a model to identify associations between disease rates and soil biodiversity.
the sheer volume of information made this a challenging task. Preparing the massive datasets for analysis took months, Ladau said. The soil samples didn’t always come from the exact same locations as the allergic children, so the researchers developed a mathematical method to account for the distance between them when drawing connections. Even so, Ladau said, “the fact that we’re seeing such a strong signal despite this mismatched dataset highlights how important microbial measures are in predicting allergic disease.”
on top of that, each soil sample…
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