Daycares in Finland Built a 'Forest Floor', And It Changed Children's Immune Systems

Daycares in Finland Built a 'Forest Floor', And It Changed Children's Immune Systems

Children’s Daycare: The whole purpose of it is right there in the name.

Daycare is a place where we leave our children for the day, trusting they will be cared for to the highest degree. In spite of this, urban daycares can often resemble concrete jungles. Yards of pavement and maybe some gravel— not exactly synonymous with wonder or enjoyment.

It seems that Finland is well ahead of the curve here. At ten different daycare centers in Lahti and Tampere, an experimental study was conducted to learn how to care better for the little ones. Researchers recreated the environment of a ‘forest floor’ within the playgrounds, to see if stepping outside and playing in a natural environment would assist children’s immune systems, or assist their wellbeing in any other meaningful way.1,2

Get Down With The Dirty Kids

The open-mindedness of the parents, the schools’ kindness, and the insight from the Finnish Advisory Board, all contributed to the plan to get the kids messier outside. Combined with research from scientists at the University of Helsinki, and approval from the ethics committee of the local hospital, the month-long study went ahead, became public, and went viral.

The reason for such media curiosity: Interesting results. They showed Finnish preschoolers had increased T-cell counts and far more diverse healthy gut bacteria, simply thanks to one month of playing in the dirt!1,2

Children’s Immune Systems Tried and Tested

The 'biodiversity hypothesis' is the idea that a world rich in beneficial microorganisms has a true effect on immunity.4

Within a real forest floor, deep in the soil, a lot of biological activity takes place. The interaction of fungi and flora with plants and animals is miraculous, as they work to find common ground, in the ground.

A pretend forest floor is a great environment to introduce kids to this joy, but how did they create it?

The playgrounds were delivered segments of forest floor and sod, planters for growing annuals, and peat blocks for climbing and digging. The children were then sent out to play, essentially to make friends with the germs, allowing their bodies to naturally adapt as needed.1 

Some of the daycares featured concrete and gravel urban yards, others brought out kids for daily nature time, and the last four had yards revamped with an undergrowth of grass and forest floor. Children in these last four daycares were given time to play five times a week in their new backyard for the next 28 days.

Dishing the dirt on the findings, environmental scientist Marja Roslund from the University of Helsinki said, ‘‘We found that the intestinal microbiota of children who received greenery was similar to the intestinal microbiota of children visiting the forest every day."1,2

These 2020 findings give a fresh meaning to the children’s lyrics ‘if you go down to the woods today you’re in for a big surprise!’4

How They Tested Children’s Immune Systems

One month after greening the yards, the participating 3–5 year-old children gave blood and/or microbial samples for analysis of blood leukocytes, and skin and stool samples, to check for bacterial communities. The parents were asked to record any feelings the children had about the activities, and even store their stool samples in home freezers.1,2 Teachers were asked to tape-record the children’s interest and knowledge of nature, their attitudes towards outdoor activities, and in general the atmosphere in the daycare centers. Child nurses collected the skin samples.1,5

Although the experiment was small, it highlights an important area of emerging research: the health benefits and immunoprotective factors we derive from nature.4

Emerging theories suggest that Inflammatory disorders may be higher in modern cities simply because of reduced exposure to beneficial microbes from the natural environment. Even exposure to household pets has been shown to alter gut microbiota and reduce allergic disease. In much of today’s world, children seem to have lost their connection to the outside world and nature. This fascinating Finnish experiment was the first to directly control the urban environment of a child, monitor for changes in the microbiome and in turn, the immune system and happiness of a child.3

Keeping the Immune System Supported Year Around

Sometimes, depending on the time of year or busy schedules, it isn’t always easy to spend time in nature. So to counteract that we recommend bringing the power of nature to you—with natural immune formulas like Mycophyto, that help to train and optimize immune function. MycoPhyto is a revolutionary, high-potency mushroom blend that works to optimize acute and long-term immune responses and reinforce overall immune function.*

Gratitude for our survival is best expressed by working together with green spaces. If we help nature to survive by having less man-made, inorganic environments, we may be victorious in regaining healthier immune systems - possibly much more than previously thought.1,3,4



A revolutionary, high-potency mushroom formula that works to optimize acute and long-term immune responses, and reinforce overall immune function.*


  1. Roslund, M., Puhakka, R., Grönroos, M., Nurminen, N., Oikarinen, S., Gazali, Group, A. (2020, October 01). Biodiversity intervention enhances immune regulation and health-associated commensal microbiota among daycare children.
  2. Cassella C. Daycares in Finland built a “forest floor”, and it changed children’s immune systems. Accessed December 4, 2020.
  3. Haahtela T, von Hertzen L, Mäkelä M, Hannuksela M, Allergy Programme Working Group. Finnish Allergy Programme 2008-2018--time to act and change the course. Allergy. 2008;63(6):634-645. 
  4. Haahtela T. A biodiversity hypothesis. Allergy. 2019;74(8):1445-1456.
  5. Belkaid Y, Hand TW. Role of the Microbiota in immunity and inflammation. Cell. 2014;157(1):121-141.