Did you know that soil bacteria can literally change your state of mind?

We all know that gardening is good for you – getting out into the fresh air, enjoying the sunshine, general benefits of physical activity, growing your own food and cultivating beautiful plants.

But if you needed another reason to get into the garden, scientists in the UK and the US have discovered that common soil bacteria can have a positive influence on your immune system and even literally change your state of mind. It’s even being explored as a treatment for cancer and inflammatory diseases including Crohn’s disease and rheumatoid arthritis. 

Exposure to Myocbacterium vaccae (pronounced “vah-kay), has been shown to have positive effects on human health. This harmless bacteria stimulates the production of serotonin which elevates mood and decreases anxiety. Low levels of serotonin have been linked with a range of physiological and mental disorders including anxiety, depression, obsessive compulsive disorder and irritable bowel syndrome.

Hand holding microbially active soil

The scientists from Bristol University and University College London identified that the

Mycobacterium activated brain cells to secrete serotonin with results similar to that provided by antidepressants. Research in the US supports these findings and also suggested that the effects could last for about three weeks.

The good news for gardeners is that Mycobacterium vaccae is found in all soil types and is particularly abundant in soils with high levels of organic matter. We inhale bacteria while digging and then ingest small particles of soil left on food harvested from the garden.

So don’t let winter get you down, just get out into the garden and get dirty!

For more information, see the TherapeuticLandscapesNetwork, Psychology Today, or (for all the scientific detail) Neuroscience journal.