According to the scientists from Bristol University in Great Britain, exposure to "friendly" bacteria found soil may help improve mood and fight depression.
The researchers discovered that mice exposed to Mycobacterium vaccae produced more serotonin - the brain chemical. A shortage of serotonin is connected with depression. Therefore, widely used antidepressant medications act by increasing serotonin levels, BBC News informed.
The results of the study are published in the journal Neuroscience.
The investigators said that further studies need to be carried out in order to find out whether Mycobacterium vaccae helps improve mood by activating serotonin neurons.
"This research helps us understand how the organism communicates with the brain and why a healthy immune system is significant for maintaining mental health," explained the lead scientist, Dr Chris Lowry.
According to BBC News, patients suffering lung cancer who are treated with Mycobacterium vaccae have anecdotally observed better quality of life.
