Back in 2014, there was a lot of buzz about how a bacteria found in soil may help reduce depression. But that’s not the only thing dirt might be good for. Additional research shows that same bacteria might even make us smarter.
Let’s start with depression. Based on results in lung cancer patients, who said their quality of life improved after being treated with Mycobacterium vaccae, a “friendly” bacteria commonly found in soil, researchers in the United Kingdom decided to find out what M. vaccae did in the brain. They learned that injections of heat-killed bacteria activated brain cells so that they produced more seratonin.
Why is that good? Seratonin is a busy neurotransmitter responsible for all kinds of things in our bodies including constricting blood vessels, sending messages between cells in the brain and within the central nervous system, regulating digestive juices and helping to control the passage of food through the gut. Low levels of seratonin have been associated with things like aggression, anxiety, depression, obsessive compulsive disorder (OCD), bipolar disorder, irritable bowel and fibromyalgia. Most drugs work on the serotonin already found in the body, so having something that can increase production is a good thing.
Knowing all that about Seratonin, and that it also plays a role in learning, a group of curious scientists looked at the results of the UK researchers and wondered if the benefits of M vaccae might extend to other areas of the brain. Could M vaccae improve learning?
Researchers Dorothy Matthews and Susan Jenks fed live M vaccae to mice and then tested how well they navigated a maze. Matthews reported that “mice that were fed live M. vaccae navigated the maze twice as fast and with less demonstrated anxiety behaviors as control mice.” When they removed the bacteria from their food, the mice were slower, but still faster than those who never got to eat the bacteria. After 3 weeks without eating M. vaccae the difference between the two groups was no longer significant, suggesting that improvements are temporary.
So what can you do with this new knowledge? I’m using it as the reason I ate dirt as a child. Mom said I had a lot of stomach troubles, so maybe I needed that extra seratonin. All that dirt may be the reason I learned to read quite early. 🙂
While none of the researchers have suggested eating dirt, they’ve all speculated that more time in the outdoors where M. vaccae is present could be a good thing. Says Matthews, “This research suggests that M. vaccae may play a role in anxiety and learning in mammals. It is interesting to speculate that creating learning environments in schools that include time in the outdoors where M. vaccae is present may decrease anxiety and improve the ability to learn new tasks.