Mechanism Discovered: How Stress Leads to Crohn’s Flare Ups

Today’s news is on a topic very near and dear to my heart, especially right now:  stress.  And the news isn’t good.

Researchers at McMaster University have isolated a mechanism by which stress causes a flare up of Crohn’s disease.[i]  And surprise, surprise – NOT – the mechanism is via the bacterial microbiome.  Using a rodent model for obvious reasons, the researchers induced stress in the animals by restraining them overnight; a 2^nd group of mice (controls) were deprived of food and water for 16 hours.  The mice in the first group showed a distinct increase in an invasive E. coli bacteria (which they call adherent-invasive E.coli (AIEC), which has already been linked to inflammatory bowel diseases (IBD).

The scientists then gave the mice AIEC, and again, either restrained them overnight or deprived them of food and water.  In the restraint group, they found that AIEC dramatically increased overnight but in the water/food deprived group, the amount of bacteria remained unchanged.  They continued their experiment for a month, weekly applying psychological stress to the animals.  The chronic stress led to a continued increase in the levels of AIEC throughout the gut.  They also found that increased levels of stress hormones (the result of chronic stress), killed off certain immune cells that make Interleukin 22 (IL-22), which is a cytokine (chemical messenger) that helps ensure that the cells of the gut wall are healthy and function normally.  Without the presence of IL-22, bacteria like E.coli can flourish in the gut and cause inflammatory flare ups, such as are seen in Crohn’s.

There is good news:  supplementing the animals with IL-22, did help correct the damage that stress hormones cause the gut tissue, as well as helping the AIEC from increasing.

The lead researchers absolutely believe this work may lead to new and improved treatments for Crohn’s disease.  Giving IL-22  to humans is currently being tested in multiple clinical trials, and using a narrow-spectrum antibiotic to kill off the AIEC might also help these patients: “…there are numerous clinical-stage investigational therapies already under development targeting the factors studied here, including IL-22 and AIEC colonization, which could be particularly beneficial in patients at high risk of stress-related disease exacerbation.”

I will follow this line of research and try to keep an eye out for the results of these trials.  Stay tuned.

And in the meantime:  a very happy and healthy 2022 to all of you.

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[i] https://www.medicalnewstoday.com/articles/crohns-how-stress-may-increase-disease-associated-bacteria-causing-flare-ups#Research-for-new-potential-treatments