Why People Often Get Sicker When They’re Stressed

Posted on March 21, 2009  Comments (5)

Researchers at UT Southwestern Medical Center identified a receptor, known as QseE, which resides in a diarrhea-causing strain of E coli. The receptor senses stress cues from the bacterium’s host and helps the pathogen make the host ill. A receptor is a molecule on the surface of a cell that docks with other molecules, often signaling the cell to carry out a specific function.

Dr. Vanessa Sperandio, associate professor of microbiology at UT Southwestern and the study’’ senior author, said QseE is an important player in disease development because the stress cues it senses from a host, chiefly epinephrine and phosphate, are generally associated with blood poisoning, or sepsis.

“Patients with high levels of phosphate in the intestine have a much higher probability of developing sepsis due to systemic infection by intestinal bacteria,” Dr. Sperandio said. “If we can find out how bacteria sense these cues, then we can try to interfere in the process and prevent infection.”

Millions of potentially harmful bacteria exist in the human body, awaiting a signal from their host that it’s time to release their toxins. Without those signals, the bacteria pass through the digestive tract without infecting cells. What hasn’t been identified is how to prevent the release of those toxins.

“There’s obviously a lot of chemical signaling between host and bacteria going on, and we have very little information about which bacteria receptors recognize the host and vice versa,” Dr. Sperandio said. “We’re scratching at the tip of the iceberg on our knowledge of this.”

“When people are stressed they have more epinephrine and norepinephrine being released. Both of these human hormones activate the receptors QseC and QseE, which in turn trigger virulence. Hence, if you are stressed, you activate bacterial virulence.” Dr. Sperandio said the findings also suggest that there may be more going on at the genetic level in stress-induced illness than previously thought.

“The problem may not only be that the stress signals are weakening your immune system, but that you’re also priming some pathogens at the same time,” she said. “Then it’s a double-edged sword. You have a weakened immune system and pathogens exploiting it.”

Previous research by Dr. Sperandio found that phentolamine, an alpha blocker drug used to treat hypertension, and a new drug called LED209 prevent QseC from expressing its virulence genes in cells. Next she will test whether phentolamine has the same effect on QseE.

Full press release: Researchers probe mechanisms of infection

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5 Responses to “Why People Often Get Sicker When They’re Stressed”

  1. GregR
    March 21st, 2009 @ 3:24 pm

    This has a lot of of truth to it. When I am stressed from work, my health really takes a hammering.
    The best remedy for this is exercise regularly.

  2. Suzanna
    March 22nd, 2009 @ 1:54 am

    never thought I’d want to find out “Why People Often Get Sicker When They’re Stressed”. its one of the things you just know! 🙂

  3. Anonymous
    March 24th, 2009 @ 4:42 am

    There is lots of truth to this article. When you allow yourself to get stressed the down side to that is you’ve already done some damage internally from allowing stress to foster which promotes sickness. The key is after you’re stressed you need to immediately do something to destress and build your immune system back up. That could be exercise, taking certain vitamins, rest, etc.

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  5. Chuck
    May 24th, 2010 @ 5:54 am

    Actually you can look at the benefits of getting sick. [Latest News– October 2009] The New York Times recently reported on a study that found that those who get less than seven hours of sleep a night are three times as likely to catch a cold as those who sleep at least eight hours a night.

    Not getting enough sleep is bad for mental and physical health but a person may be busy with his job or having fun. Then when he gets sick, he feels so sick that he wants to stay home and sleep a lot. Here is a webpage with more on this theory.

    This theory came from MDs in the late 1800s that became hygienists. Then Dr Shelton taught it to natural hygienists in the 20th century.

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