Mood Enhancers Found in Soil Bacteria

Not long ago, I remember reading about some scientists or other experts actually admitting that eating some dirt is good for you. For many years, eating dirt was considered an eating disorder called pica, which is characterized by craving non food items like laundry soap, chalk and even wet paper towels.

But minerals that our bodies need are in the soil. And eating certain types of soil can actually build up the immune system. It is well documented that children who grow up in rural areas and on farms with close, daily exposure to soil have fewer allergies and autoimmune diseases. Now, that should say something to all the moms out there running around with their Clorox wipes and Purell hand cleaner, right?

I wasn't really ready to start eating dirt even though there are some supplements sold, mostly over the Internet, that are essentially dirt capsules. Another theory is that clay soil can be good for you because toxins can bind to it, and therefore cleanse your body. And there is some evidence that certain types of clay soil called Kaolin act in the intestine much as Maalox or another antacid would do.

But scientists recently reported in the journal Neuroscience that soil can actually be a mood enhancer. A bacteria found in soil, called Mycobacterium vaccae was shown to boost serotonin production in the part of the brain that regulates mood. Serotonin is the brain chemical that antidepressants boost. This research was done on mice, of course. But brain levels of serotonin in the mice did increase when they ingested Mycobacterium vaccae.

Even human cancer patients were treated with this bacteria found in soil, and almost all of them reported an increased satisfaction with their quality of life.

Serotonin levels are also closely linked to immune function. Researchers have known for years that people with an imbalance in their immune system are more prone to depression, and other mood disorders. So there is precedent to consider serotonin levels and immune functions as tightly linked.

And if regular and repeated exposure to bacteria commonly found in soil decreases a person's risk of asthma, allergies and autoimmune disorders, it only follows that it may actually lift one's mood as well.

This may actually be why gardening is such an uplifting experience. It's the soil, not the meditative quality that makes you feel better. Getting outdoors, digging in the dirt, working in the garden have long been prescriptions to lift moods. And we might be a little closer to understanding why.

I still wouldn't run out there and start eating dirt. But I might not freak out so much when my toddler runs in with dirt smeared around her mouth.