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By Amy Norton<\/b>
HealthDay Reporter<\/i><\/p>\n
THURSDAY, Oct. 15, 2020 (HealthDay News)<\/p>\n
Want to give your kids an immune system boost? Try letting them play in the dirt more often, a new study suggests.<\/p>\n
Researchers in Finland found that when they brought nature into daycare playgrounds — including forest soil and vegetation — preschoolers’ immune function showed a change for the better. In simple terms, it shifted to a less inflammatory state.<\/p>\n
That immune system redirect was also accompanied by some changes in the children’s microbiome — the vast collection of bacteria and other microbes that naturally live on and in the body. Research has revealed those bugs to be vital in normal body processes — from metabolism to brain function to immune system regulation.<\/p>\n
It’s too early to know whether bringing the forest to urban playgrounds has real health benefits, experts said.<\/p>\n
But the findings do argue for regular, messy outdoor time.<\/p>\n
“I highly recommend letting children play in the dirt,” said senior researcher Aki Sinkkonen, of the Natural Resources Institute Finland, in Turku.<\/p>\n
The study, published online Oct. 14 in Science Advances<\/i>, grew from a body of research on modern living and immune function. Many studies, for instance, have found that living on a farm — especially during childhood — is tied to a lower risk of allergies<\/a>. Meanwhile, the trappings of modern life — from antibacterial soaps to processed foods to widespread antibiotic use — are thought to reduce the diversity in the body’s microbial communities.<\/p>\n In general, researchers believe, the greater the diversity in the microbiome, the better.<\/p>\n Sinkkonen’s team decided to test the notion that adding “biodiversity” to an urban setting might boost the diversity in kids’ microbiomes, and alter their immune function.<\/p>\n The researchers recruited 10 city daycare centers, with a total of 75 children aged 3 to 5. At four centers, the researchers transformed gravel playgrounds with forest soil and sod, planters for growing annuals and peat blocks for kids to climb.<\/p>\n The rest of the centers served as a comparison. Three were “nature-oriented” centers where young children were regularly taken on trips to nearby forests; at the other three, gravelly playgrounds remained the norm.<\/p>\n After one month, children at centers that imported the forest showed an increased diversity in certain bacteria on the skin. That made them more similar to children at the nature-oriented centers, the study authors explained.<\/p>\n In contrast, the skin’s bacterial diversity generally declined among children at standard daycare centers, the findings showed.<\/p>\n Meanwhile, the green playgrounds changed kids’ immune systems, too. Their blood samples showed a heightened ratio of an anti-inflammatory immune system protein called IL-10, in relation to a pro-inflammatory protein called IL-17A.<\/p>\n Jack Gilbert, a microbiome researcher not involved in the study, praised its “holistic” approach. But he also had caveats.<\/p>\n “They had a very small sample size, and showed small effects,” said Gilbert, a professor at the University of California, San Diego School of Medicine.<\/p>\n The tactic, he said, will have to be tested at more schools, and involve many more children.<\/p>\n And the ultimate question, Gilbert said, is whether children can reap health benefits — like lower risks of eczema<\/a> or food allergy<\/a>.<\/p>\n Gilbert doubted that the limited microbiome changes were responsible for the immune system findings. Instead, he thinks it went the other way: Kids’ time digging in microbe-rich dirt altered their immune systems, and that tweaked the body’s microbiome.<\/p>\n “To me, the key finding is the change in the immune system,” Gilbert said.<\/p>\n While many questions remain, he echoed Sinkkonen’s advice on young children’s playtime. “I do think being in the dirt is good,” Gilbert said.<\/p>\n Sinkkonen noted that in this study, microbe diversity in the top layer of soil seemed to be critical. And kids were actively playing in it — digging around, planting vegetation. So, it’s unlikely, Sinkkonen said, that simply putting down some grass and shrubs would suffice.<\/p>\n The researchers do plan to pursue the question of health benefits. Sinkkonen said they are beginning a study to see whether exposing babies<\/a> to more biodiversity, for 10 months, can reduce the risk of allergies<\/a>.<\/p>\n![\"MedicalNews\"](\"https:\/\/images.medicinenet.com\/images\/HealthDay\/healthday.png\")
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