The bacteria has also been linked to reduced anxiety and higher serotonin levels.
Exposure to a common bacteria present in the soil boosts learning behaviour.
The bacteria — mycobacterium vaccae — may also act as an antidepressant and lower anxiety.
We can probably get sufficient exposure to the bacteria by simply working in the garden, walking through the woods or digging in the dirt.
For thousands of years human beings have lived close to nature.
It is only recently, with the advent of industrialisation, that we have begun leading such antiseptic lives.
Being closer to nature probably has considerable benefits to both health and cognition.
The conclusions come from a study in which mice were fed the bacteria.
The results showed they navigated a maze at twice the speed.
Dr Dorothy Matthews, the study’s lead author, explained:
“Mycobacterium vaccae is a natural soil bacterium which people likely ingest or breath in when they spend time in nature.”
For the study, mice were fed a diet with the M. vaccae bacteria added to it.
The idea was inspired by previous research that involved injecting the deactivated bacteria into mice.
The bacteria spurred on growth of neurons, boosted serotonin levels and decreased anxiety.
Dr Matthews said:
“Since serotonin plays a role in learning we wondered if live M. vaccae could improve learning in mice.
We found that mice that were fed live M. vaccae navigated the maze twice as fast and with less demonstrated anxiety behaviors as control mice.”
Once taken off the diet, though, the mice slowed down somewhat, although they were still faster than the control mice.
Dr Matthews said:
“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.”
The study was published in the journal Behavioural Processes (Matthews & Jenks, 2013).
