Health Blog: How Bacteria Use our Own Stress Molecules

Share

Tweet

Email This Page

Sign up here for
our Newsletter: *

Bacteria, stress molecules can gang up against us

It is now common knowledge that stress can negatively impact immunity. But it is not widely known that bacteria may actually use our own stress molecules to take advantage of us. When we are under stress, the level of stress compounds such as norepinephrine (a form of adrenaline) increase in our bodies. These levels also increase in the intestinal tract, which is part of a network that accounts for almost 50 percent of the adrenaline produced in the entire body (the mesenteric organs).[i] New research suggests that norepinephrine can stimulate the growth of a range of harmful bacteria in the gut. In one study, for example, the common gut-infecting bacteria Campylobacter jejuni was found to be more invasive in the presence of norepinephrine.[ii]

At the University of Texas Southwestern Medical Center, Dr. Vanessa Sperandio has been studying the harmful forms of E. coli that can infect our gut. Among these is the notorious E. coli O157:H7, which is known to cause severe kidney damage and even death. It is most well known for contaminating improperly cooked hamburger and causes illness in over 70,000 people in the U.S. each year. Dr. Sperandio found that epinephrine (adrenaline) helps to alert this form of E. coli that it is in the intestinal tract, which seems to trigger the E. coli to activate its virulence (harm-causing) genes.[iii]

Another bacterium that can have severe effects on us is called Pseudomonas aeruginosa. In fact, this microbe has been found to prove fatal in some 40 percent of hospitalized patients who contract the infection. It appears that P. aeruginosa is another bacterium that is good at using the stress molecules epinephrine and norepinephrine to get a foothold in our intestines. The stress molecules are used by the bacteria to switch on their virulence genes, compete with our beneficial gut bacteria, and exact a severe toll on the body.[iv]

More reasons to manage your stress …

This is really quite extraordinary. Bacteria use our stress chemicals to signal they are inside a human being. These stress chemicals are then used to switch on genes that help the bacteria defend themselves against us or become more virulent. This raises the stakes in our efforts to understand the psychology of the stress response and in building the life skills that help us thrive in our complex world. 

© 2010 Michael A. Schmidt, Ph.D.

Next: The surprising ways life’s troubles affect your body 

Read more of Michael Schmidt's health blogs here.

Read other WellWise health bloggers here.

Click here to return to WellWise.org's homepage. 

References:

[i] Eisenhofer, G, Aneman, A, Hooper, D, et al. Mesenteric organ production, hepatic metabolism, and renal elimination of norepinephrine and its metabolites in humans. J Neurochem 1996;66:1565-1573.

[ii] Cogan, TA, Thomas, AO, Rees, LE. Norepinephrine increases the pathogenic potential of Campylobacter jejuni. Gut 2007;56(8):1060-5.

[iii] Walters, M, Sperandio, V. Quorum sensing in Escherichia coli and Salmonella. Int J Med Microbiol 2006;296(2-3):125-31.

[iv] Alverdy, J, Zaborina, O, Wu, L. The impact of stress and nutrition on bacterial–host interactions at the intestinal epithelial surface. Curr Opin in Clin Nutr Metab Care 2005;8:205–209.