Nature Truly Does Ease Anxiety

Two microbiologists with The Sage Colleges in New York recently presented the results of a very interesting experiment that they had done. Dorothy Matthews and Susan Jenks revealed their findings at a meeting of the American Society for Microbiology. Their experiments involved feeding mice a common bacteria found in soil and the results may give a scientific basis to the relaxation many people feel when communing with nature.

The experiment was created to pursue research that had been published in Britain back in 2007 which had shown that mice injected with this same bacteria were found to have an increased level of serotonin and a decrease in anxiety. Since another function of serotonin is to stimulate learning, Matthews and Jenks wanted to see if the bacteria could help the mice learn faster or more complicated tasks.

The pair started with twenty immature mice. The mice were allowed a couple weeks to both mature and be comfortable in their new environment. During this time, the mice were rewarded with bread with peanut butter on it for completing a maze successfully.

Once the mice were mature and used to their routine, they were split into two even groups. The control group continued with the same routine while the experimental group was given the same reward but with some of the Mycobacterium vaccae. Both groups were put through the same maze a dozen times over the course of three weeks.

The control group showed signs of anxiety, like freezing up or even turning back to the starting point. The experimental group receiving the bacteria, on the other hand, stayed focused, showed no signs of anxiety and completed the maze in half the time of the control group.

After the initial three weeks, none of the mice were given further bacteria. Two weeks after the initial experiment, the experimental group were still performing better than the controls but not as much as before. One week later, the test was performed a final time and the experimental group was only a fraction faster. Clearly, for the bacteria to be beneficial, it had to be given on an ongoing basis.

According to Matthews, for this bacteria to be beneficial for humans, simply contacting nature on a regular basis should be sufficient as we would come into contact with the bacteria raking leaves or even walking through the woods.