In a world where we have taught our children to wash their hands within an inch of their life, new research now says we should get them dirty. The research is published in the journal Science Advances and involved children aged 3-5 in schools where they covered some of the outdoor areas with forest floor shrubs and plants. The children spent an average of 90 minutes a day outside and were encouraged to play with the plants and soil.Tests after 28 days showed the diversity of microbes on the children’s skin was a third higher and significantly increased in the gut. Blood samples showed beneficial changes to to the immune system, including anti-inflammatory cytokine and regulatory T cells. So if you want to help to boost your children’s immune systems - give them some soil.