Medical Health Research

Studies Show Probiotics Reduce Anxiety in Mice Probiotics are living microorganisms thought to be beneficial to the digestive system.

Often called “good bacteria,” they are similar to the bacteria found in the stomach and are consumed through foods and dietary supplements. Complementary and alternative medicine frequently recommends probiotics to restore the natural balance of the stomach after use of antibiotics or the presence of unhealthy microorganisms, such as yeast and fungi.

Although more scientific research is needed, some medical professionals think probiotics help to keep the immune system healthy and contribute to good physical health. A recent study released by the “Proceedings of the National Academy of Sciences,” however, says that probiotics may contribute to good mental health, as well.

In a study that was done over a two-week period at two independent universities, researchers were able to reduce stress and anxiety in mice by feeding them broth containing probiotics. Scientists have long known that the stomach and the brain communicate, but the mechanism through which this takes place was a mystery.

Research showed that probiotics altered GABA receptors, one of the neurotransmitters responsible for calming the brain, through a process involving the vagus nerve. Although the study was done on mice with lactobacillus – one of many probiotics – results were striking enough to suggest further investigation.

Scientists were looking for the answers to these questions:

Whether feeding mice with a probiotic would change their behavior
How lactobacillus would affect the stress level of the mice
The mechanism through which the changes occurred

Results of the study emphasized that the research was done on mice with a single microorganism that is not available in food products. The findings are in their early stages, and researchers do not know what results will occur with other kinds of probiotics. They also advise against assuming the same reaction will occur in humans. On the other hand, scientists were stunned that the lactobacillus had essentially the same effect on the mice as a heavy dose of tranquilizers.

Science has already shown that stress affects the balance of healthy bacteria in the human gut. More research is needed to determine whether the presence of healthy bacteria can affect the neurotransmitters in the brain.­