In the last decade, scientists have discovered thatbehavior, mood and even memory can be altered by the action of external microbes. A clear example is the effects caused by being in contact withMycobacterium vaccae, a bacterium thatlives on the groundand that we inhale when we take a walk in the field, play for a while in the park or we can plant the garden. According to a study published a few years ago in the journalNeuroscience, this microbe estimulates neurons in the prefrontal cortex of the human brain to release serotonin, the neurotransmitter for happiness and well-being, which puts us in a very good mood. What’s more, Christopher Lowry, a neuroscientist at the University of Bristol (UK), has found that injecting the bacteria into laboratory mice exerted an antidepressant effect very similar to the popular Prozac.
As if this were not enough, Dorothy Matthews, a researcher at The Sages Colleges in New York (USA), has come to the surprising conclusion thatM. vaccae can also improve learning ability. In experiments with rodents fed the live bacteria, Matthews and his team found that “infected” animals moved faster through mazes and suffered less anxiety. “We can speculate that it would be positive to program a type of outdoor learning in schools to acquire new skills,” suggests Matthews. In view of these results, it does not seem unreasonable to imagine that, in the not too distant future, we can takea handful of these bacteria to make us happier and smarter. In fact, in 2003 Rook and Lowry already took the first step in this direction by obtaining a patent for theuse of M. vaccae and derivatives to treat anxiety, panic attacks, and eating disorders.





