Finnish studies link nature contact to short-term changes in skin microbes

Research in Finland is examining whether contact with soil, peat, moss and other natural materials can affect the skin microbiome and immune regulation. Scientists at the Finnish Environment Institute found that a 20-second exposure increased the abundance and variety of microbes on participants’ skin, although the changes quickly diminished after exposure ended.

Studies involving children have reported similar effects. At the Aurinkolinna daycare centre, researchers are tracking children who play regularly in a nature-rich yard as part of the Vahvistu research project. Earlier work found that children who played on forest-floor materials had greater skin microbial diversity than those who used paved yards, with fewer potential pathogens detected on their skin.

Other research found changes in cytokines, immune-signalling proteins, among children who played in sand enriched with microbially diverse soil. The findings are consistent with the biodiversity hypothesis, which proposes that exposure to diverse environmental microbes may influence the human microbiome and immune function.

Related studies of adults found that gardening with microbially diverse soil was associated with increased skin microbial diversity and higher levels of anti-inflammatory cytokines. Workers in Finnish offices with indoor green walls also showed changes in skin microbes and lower levels of pro-inflammatory cytokines after two weeks.

The research does not establish that contact with nature prevents or treats eczema, asthma, allergies or other immune-mediated conditions. The duration and amount of exposure required for lasting effects are also unclear, and the studies primarily measure biological changes rather than long-term clinical outcomes. Broader research is needed to determine whether the associations translate into meaningful health benefits.