Mud kitchens and bugs for a healthy start

Kindergartens are exposing children to more mud, wild plants and fungi-and proving the benefits of biodiversity on wellbeing

- Phoebe Weston

Aurora Nikula, 5, is having a normal day at her nursery. She is making a cake out of sand and mud, adding in make-believe carrots, potatoes and meat. “It’s overcooked,” she says as she splashes water in, then adds another dollop of sand. “More sugar, it tastes better,” she says. A handful of mud goes in, and the dish evolves into a chocolate cake.

Aki Sinkkonen, a principal scientist with the Natural Resources Institute Finland, is watching. He’s also very interested in Aurora’s cake, but for different reasons. “Perfect,” he says, admiring the way she is mixing soil, sand and leaves and then putting it on her face. “She’s really getting her hands in it.”

To a hygiene-conscious kindergarten, this could be a problem, but at Humpula daycare centre in Lahti, north of Helsinki, children are encouraged to get muddy. Across Finland, 43 daycare centres have been awarded €1m ($1.16m) to rewild yards and to increase children’s exposure to the microscopic biodiversity - such as bacteria and fungi - that lives in nature.

We already know that access to the outdoors is important for children and their development. But this study goes one step further. It is part of a growing body of research linking two layers of biodiversity. There is the outer layer - the more familiar vision of biodiversity, made up of soil, water, plants, animals and microbial life, that lives in the forest playground (or any other environment). And then there is the inner layer: the biodiversity that lives within and upon the human body, including the gut, skin and airways.

Increasingly, scientists are learning that our health is intimately linked to our surroundings, and to the ecological health of the world around us. The first 1,000 days of human life - when the brain and body are most rapidly developing - are considered particularly crucial.