Soil bug could help improve memory say researchers

COUNTRY bumpkins may not deserve their simpleton reputation, as living close to the soil could make them brighter than sophisticated urbanites, research suggests.

Scientists in the US have discovered that a common soil bug improves the learning ability of mice.

They speculate whether it might also help make humans smarter, especially children.

Previous research indicated that the bacteria stimulate the growth of neurons and alter brain chemistry. The new findings suggest the bug can improve both mood and memory.

Study leader Dorothy Matthews, from the Sage Colleges in Troy, New York, said: "Mycobacterium vaccae is a natural soil bacterium which people likely breathe in when they spend time in nature.

"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."

In the new research, presented yesterday at the American Society for Microbiology's annual meeting in San Diego, California, Dr Matthews's team investigated whether the soil bug had an effect on learning.

Live bacteria were fed to mice that were then timed as they taught themselves how to navigate a maze. Their performance was compared with that of a group of "control" mice not fed the bacteria.

"We found that mice that were fed live M vaccae navigated the maze twice as fast and with less demonstrated anxiety behaviours as control mice," said Dr Matthews.

The effect lingered for a short time after the bacteria were removed from the animals' diets.

When mice were retested having returned to a normal diet they ran the maze slower than before, but still faster than animals never given the bacteria.