Mood-boosting Bacteria Found in Dirt - Mycobacterium vaccae

They also leave us wondering if we shouldn't all be spending more time playing in the dirt.
~Neuroscientist Dr. Christopher Lowry

Mycobacterium vaccae, a bacteria found in dirt, stimulates the immune system and boosts the production of serotonin, a mood-regulating brain chemical. M vaccae has been used as a vaccine against tuberculosis, and is being tested as a treatment for cancer patients and in asthma sufferers to control the allergic reactions and help ‘rebalance’ the immune system.

Studies on mice led by neuroscientists at the University of Bristol suggest the bacteria may have applications as a treatment for depression. A chance observation by oncologist Mary O'Brien who was trying an experimental treatment for cancer that involved inoculating patients with Mycobacterium vaccae led to the University of Bristol study. When the inoculation was administered there were fewer cancer symptoms, and an improvement in patients' emotional health and mood.

 The study also lends support to the "hygiene hypothesis"  - that exposure to common bacteria from a young age helps balance the immune system and  make us less vulnerable to disease.


The study: Identification of an immune-responsive mesolimbocortical serotonergic system: Potential role in regulation of emotional behavior

Note: The initial discovery of  the antidepressant qualities of M vaccae was 10 years ago.

Something else I learned: Stress free mice enjoy swimming.