Contact with Soil and Nature Boosts Skin Microbiome and Immune Health

Spending time outdoors and physically engaging with natural elements like soil, plants, and trees can provide measurable health benefits beyond the usual sensory enjoyment. Recent studies indicate that touching soil and vegetation increases the diversity and abundance of microbes on the skin, which plays a crucial role in maintaining a balanced and healthy immune system. Mira Grönroos, an ecologist and nature-health researcher at the Finnish Environment Institute, conducted experiments where participants rubbed their hands with soil, peat, and moss for just 20 seconds. Despite washing their hands afterward, the microbial diversity on their skin significantly increased. This microbial variety helps prevent harmful bacteria from dominating, thereby supporting skin health and immune function. Children at the Aurinkolinna daycare center in Finland regularly play outdoors in a natural environment rich with trees, soil, and woodchips. Researchers studying these children over several years found that those exposed to this biodiverse environment had greater microbial diversity on their skin compared to children playing in paved areas. This diversity is linked to fewer potential pathogens and a more balanced skin microbiome. Further research demonstrated that children playing in microbially enriched sandboxes showed changes in immune markers that suggest improved immunoregulation, meaning their immune systems could better manage threats without overreacting. These findings support the biodiversity hypothesis, which proposes that reduced environmental biodiversity may contribute to the rise in immune-related conditions. Adults also benefit from contact with diverse microbes. In one study, participants who grew vegetables indoors in microbially rich soil experienced increased skin microbial diversity and higher levels of anti-inflammatory markers in their blood. Similarly, installing living plant walls in office environments led to increased skin microbial diversity and reduced inflammation markers. These studies underscore the potential health advantages of integrating natural, microbially diverse environments into daily life. Encouraging regular, even incidental, contact with nature—such as touching tree bark, gardening, or spending time in green spaces—may help enhance skin microbial communities and support immune health. While more research is needed to fully understand the implications for specific immune-related diseases, current evidence suggests that embracing nature contact carries low risk and offers multiple potential benefits. Experts advocate for urban planning that incorporates accessible natural elements to facilitate regular exposure to beneficial microbes. Overall, these findings encourage a reconsideration of our relationship with the natural world, highlighting the value of getting our hands dirty as a simple way to promote better health.