Greening the kindergarten yard reduced the probability of potential pathogenic bacteria succeeding on children’s skin

The research article written by Marja Roslund et al. has been published in Environmental International.

According to the biodiversity hypothesis, reduced exposure to nature’s diverse microbiome increases the risk of developing disorders of the immune system, such as allergies, type 1 diabetes, and celiac disease. Immune-mediated diseases have increased, especially in urbanized societies.

This two-year study investigated how the greening of an urban kindergarten affects the microbiome of the yard and the children’s skin and intestines. The study compared greened daycare centers and modern urban daycare centers, whose yard mainly has asphalt, sand, gravel and plastic mats. In the yards of the kindergartens to be greened, forest soil was brought, i.e. the municipality, transplanted grass and soil boxes, in which the children planted plants and took care of them.

In an earlier month-long study, it was found that contact with greenery diversified the microbiome of children’s skin, which was connected to better immune defense function. In this now published study, it was found that the skin of the children who received the green garden had less potential pathogenic bacteria compared to the control group. This observation was made one year after the kindergarten yards had been modified with green materials. In addition, even though the forest floor was trampled while the children were playing, a diverse and useful microbiota remained in the kindergarten’s yard during the two-year follow-up.

According to researchers, the green materials of the kindergarten yard contain a diverse and health-beneficial microbial community, which reduces the success of possible disease-causing bacteria on the skin and can promote the development of children’s immune defenses.

Environment International: Long-term biodiversity intervention shapes health-associated commensal microbiota among urban day-care children