Stress relief could someday be an immunization away

A researcher examines a sample of Mycobacterium vaccae. Source:

There’s a bacterium found on the shores of a Ugandan lake that could help reduce our stress. Scientists recently injected it into stressed-out mice with promising results.

The bacterium, called Mycobacterium vaccae, reduces inflammation in the brain, which in turn prepares the brain to respond better to stress. These findings could lead to better treatments for PTSD, anxiety, and depression.

In the study, researchers injected mice with the bacterium three times, a week apart. Eight days after the last injection, the mice’s brains showed higher levels of an anti-inflammatory protein in the hippocampus, a region of the brain involved in regulating anxiety.

They then placed the mice in a cage with a larger, aggressive mouse. The injected mice showed fewer symptoms of anxiety in the stressful situation, and they had lower levels of a stress-induced, inflammation promoting protein called HMGB1 and higher levels of an anti-inflammatory receptor called CD200R1.

Researchers say other probiotics (helpful bacteria) could have similar effects, and studies are under way to explore how they can be used. One potential use would be as a preventative treatment for people going into stressful situations, like combat or emergency room employment.

There’s so much more to understand about how mental illness works, and this is an interesting step in the right direction.

Satu Woodland is owner and clinician of Mental Health Solutions, an integrative mental health practice located at Bown Crossing in Boise, Idaho. If you would like to discuss the information in this blog further with her, please call 208-918-0958. She sees adolescents and adults. Information in this blog is not intended as medical advice. Please consult your health care provider about decisions regarding your health.


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