The prevention of many diseases has significantly improved by intervening in known risk factors. However, the causes of the increase in allergy and type 1 diabetes are unknown. These diseases are often associated with a low-grade inflammation and immunological imbalance. The lifestyle and environment of urbanized populations have changed causing imbalance in the human normal flora and affecting immune regulation. We discuss everyday factors affecting immune regulation, using allergy as an example. Health may be promoted through the "nature step", by supporting the connection between humans and nature.