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Gut feeling. A steady diet of Lactobacillus rhamnosus (above) appears to reduce anxiety in mice.
Gut feeling. A steady diet of Lactobacillus rhamnosus (above) appears to reduce anxiety in mice.
In recent years, researchers have become increasingly interested in how gut bacteria might influence the brain and behavior, says John Cryan, a neuroscientist at University College Cork in Ireland. So far, most of the work has focused on how pathogenic bugs influence the brain by releasing toxins or stimulating the immune system, Cryan says. One recent study suggested that even benign bacteria can alter the brain and behavior, but until now there has been very little work in this area, Cryan says.
To further investigate the mind-altering potential of benign bacteria, Cryan and colleagues at McMaster University in Canada fed mice a broth containing a benign bacterium, Lactobacillus rhamnosus. The scientists chose this particular bug partly because they had a handy supply and also because related Lactobacillus bacteria are a major ingredient of probiotic supplements and very little is known about their potential side effects, Cryan says.
