Researchers are now studying a possible immunization against stress that is generated from good natural bacteria which have already been proven as effective mood enhancers.

The vaccine has the potential to protect the brain with long-lasting anti-inflammatory effects, thereby making people more resilient to the physical and behavioral effects of stress. The authors of the study said the probiotic-based immunization could fight posttraumatic stress disorder, anxiety, and depression in the future.

Probiotics-based Immunization For Stress

The researchers from the University of Colorado Boulder highlighted previous studies, which found that stress can cause inflammation in the brain that could lead to mental disorders. Specifically, stress could negatively impact the neurotransmitters in the brain, such as the norepinephrine or dopamine, which are responsible for the people's mood.

On the other hand, probiotics have already shown its capability to positively affect the cognitive functions of the brain, thereby reducing the risks for anxiety and fear.

With these insights, the scientists set out to try whether there is a way that probiotics could directly protect the brain once it is affected by stress-induced inflammation.

Mycobacterium Vaccae

The study, published in the journal Brain, Behavior, and Immunity, has specifically looked into the possibility of using the Mycobacterium vaccae for the immunization.

Mycobacterium vaccae is not commercially available. It was discovered on the shores of Lake Kyoga in Uganda in the 1990's. The immunologists who found it had initially discovered that people in the place responded positively to a certain type of tuberculosis vaccine. Upon further examination, they found that the bacterium found on the soil in the lakeshore was enhancing the efficacy of the tuberculosis vaccine.

A team of researchers had subsequently tried to cure lung cancer patients with the Mycobacterium vaccae. While it did not extend the lives of the patients, the bacterium enhanced the patients' moods.

A separate study by the American Society for Microbiology, published in 2010, said that Mycobacterium vaccae is a natural soil bacterium that people naturally ingest or breath when they are out exploring nature. This specific bacterium has antidepressant qualities that could also increase learning behavior according to the study.

Immunization For Stress In Male Rodents

The researcher had already tried injecting male rodents with the Mycobacterium Vaccae to determine exactly what the bacterium does to the brain.

"We found that in rodents this particular bacterium, Mycobacterium vaccae, actually shifts the environment in the brain toward an anti-inflammatory state," said Matthew Frank, the lead author for the study and a senior research associate in the university.

"If you could do that in people, it could have broad implications for a number of neuroinflammatory diseases," he added.

The researchers highlighted that stress-related mental disorders, like anxiety and PSTD, affect one in four people.

Christopher Lowry, the senior author for the study and an associate professor in integrative physiology, has been studying Mycobacterium Vaccae for 17 years. He said he envisions a future where the bacterium or any other good bacteria could be utilized to safeguard the brain from the destructive effects of stress.

The next step for the researchers is to replicate the result of the Mycobacterium vaccae experiment in rodents to humans through a clinical trial.