The results so far suggest that simply inhaling M. vaccae—you get a dose just by taking a walk in the wild or rooting around in the garden—could help elicit a jolly state of mind.
You now have a new reason to make mud pies — and lick the spoon if you feel like it! A recent study has revealed that ingesting soil bacteria (or Mycobacterium vaccae) not only makes your immune system more capable of handling allergens like bee pollen and cat dander, but also increases the release of serotonin into your brain. This means that playing in the dirt induces a natural happiness high that could help to combat depression, bodily pains and other common ailments. So don’t give in to washing your hands multiple times an hour in fear of catching the next swine flu — go stick them in a pile of dirt instead!