Common, abundant bacteria may hold key to treating stress disorders

Common, abundant bacteria may hold key to treating stress disorders
May 16, 2016
Christopher Lowry
It lives in dirt and it’s good for you, so says CU-Boulder researcher Christopher
Lowry who is lead author of a study showing that a common and abundant bacteria
found in soil can boost the immune system to help fight stress and inflammation.
CUT 1 “Called mycobacterium vaccae, and this is a very common, abundant
bacterium that’s found in the soil. And the thing to keep in mind is that throughout
human evolution humans would have been exposed to large quantities of these
types of bacteria. (:15) These types of bacteria have been referred to as ‘Old Friends’
because humans co-evolved with these bacteria. They are non-pathogenic. And what
we’ve learned is that they’re immunoregulatory. They can actually suppress
inappropriate inflammation.” (:29)
Lowry is an associate professor of integrative physiology. For the study researchers
injected mice with the bacteria and after a few weeks, mice exposed to the bacteria
responded by showing stress resistance and improved coping behaviors.
CUT 2 “We exposed the mice to a psycho-social stressor where they were co-housed
with a larger male that’s dominant. And mice naturally form dominant-subordinate
hierarchies. (:12) And what we found is that when mice were immunized they didn’t
show these submissive behaviors or they showed them at a greatly reduced level.
And what we found is that there is a shift toward a more proactive or less reactive,
less passive behavioral strategy.” (:29)
Lowry says this summer his research team will hold human clinical trials testing the
bacteria on people who have strong inflammatory responses to stress. He says if
they respond as the mice did after exposure to the bacteria then it could alter the
way we treat people for stress and depression disorders.
CUT 3 “Individuals that have a propensity to respond with strong inflammatory
responses are at a higher risk for stress related psychiatric disorders. And we can
measure this in humans using bio-markers of inflammation. (:17) So the prediction is
if you can prevent or suppress those inflammatory responses then you would lower
the risk for development of stress related psychiatric disorders.” (:24)
Lowry adds the researchers also found that M. vaccae prevented stress-induced
colitis, a typical symptom of inflammatory bowel disease (IBD), suggesting that
immunization with the bacteria may have a wide-ranging suite of health benefits.
CUT 4 “This could be applied very soon in a clinical context because we know that
there are very good immunoregulatory agents that can suppress inappropriate
inflammation.” (:13)
The findings appear today in the journal Proceedings of the National Academy of
Sciences.
-CU-