by Michael W. Sherer, thriller author
In honor of the holidays, when we all likely indulge in too
much rich food, too many glasses of our
favorite libation, too much stress and
too little sleep, I thought I’d offer up some food for thought. We’ve all heard
the old saw “you are what you eat.” It turns out it may be true in ways we
never dreamed of.
We think of our physical selves as skeletons and organs wrapped
in muscle and covered with skin. Most of our parts are similar to those of
everyone else. In some cases they’re even interchangeable (though not exactly
plug-and-play). Scientists have discovered, though, that the cells comprising
all the microorganisms on and inside us—the flora and fauna of our individual
ecosystems—than there are body cells.
Some of these microorganisms are good for us, some bad. H. pylori, for example, a bacterium
sometimes found in the gut, causes peptic ulcers. Scientists once thought the
acid environment in your stomach was so hostile that no bacteria could live
there for long. Up until 1982, most thought that ulcers were caused by spicy
food or too much acid. A couple of Australian scientists (a doctor and a
pathologist) finally cultured the bacteria when they unintentionally left their
Petri dishes out over a five-day Easter weekend. To prove that H. pylori
actually caused ulcers without having to go through years of experiments with
lab animals and human trials, one of them drank a beaker of the culture and
within ten days had developed gastritis and an ulcer.
Scientists now are learning even more about these little
creatures that live inside us, and some now think that microbes in our gut may
actually influence how we think. And you thought that gut feeling was just
instinct. MRI exams of people’s brains show that connections between different
areas within the brain vary depending on which species of bacteria dominate
their gut.
In mice, scientists have exchanged the gut bacteria of
anxious mice with that of fearless mice, and the behavior of each changed.
Fearless mice became more timid, and anxious mice took more chances. They also
measured changes in brain chemistry and found that feeding the mice probiotics
or antibiotics to change the mix of microbes in their gut also changed brain
chemistry that affects mood and behavior.
One of the ways the gut “talks” to the brain is through the
vagus nerve that runs from brain to abdomen. When researchers in Ireland cut
this nerve in mice, the brain no longer responded to changes in gut microbes.
The experiments have even expanded to include symptoms of autism in mice. By
altering the mix of microbes in the gut with probiotics, researchers have been
able to ameliorate autism in mice. A study on people with bipolar disorder is
having similar results so far.
Perhaps even more far-reaching, though, is the fact that
researchers now believe that soon it may be possible to identify people by
their unique “microbiome” signature. On a body farm at Sam Houston State
University in Texas, pathologists are learning how to improve time-of-death
accuracy through the study of microorganisms, not just insects. And researchers
say that someday pathologists may be able to use microbiome signatures to
identify how and where someone died, and even the perpetrator if the victim was
murdered.
A researcher at Sam Houston State University's body farm, also known as the Southeast Texas Applied Forensic Science Facility. |
When you’re tempted to have that extra helping of turkey and
mashed potatoes or another slice of pie during the next week or two, remember
that it’s not just the extra calories you’ll be packing in—you literally are
what you eat.
Happy holidays!
He and his family now reside in the Seattle area. Please visit him at www.michaelwsherer.com or you can follow him on Facebook at www.facebook.com/thrillerauthor and on Twitter @MysteryNovelist.
Fascinating stuff! Our understanding of the importance of gut microbes is steadily growing. Fecal transfers between humans, which are essentially intestinal-bacteria transfers, have been shown to cure people of deadly infections and other diseases.
ReplyDeleteA family member just had her colon surgically removed—to save her life—and now I'm wondering if they should have tried to alter her intestinal microbes instead. I would have gladly volunteered to be a donor.
The idea of a microbial signature playing a part in homicide investigations is equally fascinating. I'm making notes in my idea files now.