Why Gardening is Good for Body and Mind

8. Healthy Bacteria in the Dirt

Digging in the garden releases [citation href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1868963/" title=Neuroscience" desc="Identification of an immune-responsive mesolimbocortical serotonergic system: Potential role in regulation of emotional behavior"]Mycobacterium vaccae, a type of bacteria that lives in the soil. When the gardener breathes them in, the bacteria activate neurons in the brain that release serotonin, similar to antidepressants. M. vaccae trains the immune system to ignore allergens like pollen and dog dandruff. In one study, researchers administered the bacteria to individuals with lung cancer and found that it lowered pain levels and reduced nausea.