That queasy feeling, butterflies in the stomach, a lump in the throat which we all have experienced at one time or another. Studies have shown that these gut reactions are responses to our psychosocial environment and circumstances -- travel, school examinations, public speaking, dietary indiscretions are familiar provocations. We often respond to strong emotions or changes in circumstances with such digestive symptoms as nausea, heartburn, abdominal discomfort, or altered bowel habit. But why the gut ? And how does the brain factor in all of these? The Enteric Nervous System (ENS) and its neurotransmitters influenced by hormones play a role in this process because the gut and the brain are linked.
Gut is an old
Anglo-Saxon word that applies to the passage from the mouth to the anus. The
word intestine, like many Franco-English words, may appeal to the sensitive,
but it excludes the stomach and the esophagus. Bowel and intestine refer only
to the lower gut. The digestive, alimentary, or gastrointestinal tracts may get
around some of the difficulties of other terms but also include the pancreas
and the liver. Seldom are these terms used outside medical meetings. Perhaps
the word GUT is less objectionable nowadays; it is after all, the title of a
distinguished British medical journal.
The histology of the
gut is very complex. The ability of the muscles of the digestive tract to
undergo contraction ( motility) is influenced by a variety of reflexes that
respond to the concentration, osmolarity size, and nature of luminal contents
and to events occurring elsewhere in the gut.
The gut often provides
an outlet for the emotions. The relationship of soma to psyche is perhaps greater than many will
admit, even though it is apparent that our guts react to events in our
environment. Who has escaped the queasy stomach or the loose bowels that often
accompany stressful events? Such "gut feelings" may occur in a
variety of situations: at a board meeting, during business negotiations, or at
a soccer game. The effect of emotion on gut function, however profound, is
unpredictable. When soldiers are ordered into battle, for example, some are nauseated, some vomit, and some
experience a curious sense of well-being---a release at the prospect of action.
It is a common experience that contemplation of a difficult situation may
elicit more gut reaction than the situation itself.
Moreover, the nervous
connections between the brain and the gut may seem like a one-way street. However, case studies show
that there is more traffic from the gut
to the brain than vice-versa. It is evident that a diseased gut sends these
signals to the brain, and that these signals may have a profound effect on
emotion and behavior. The gut and the mind are clearly linked. Normally, the gut works silently accepting whatever we
feed into it and seldom intruding into our consciousness except to signal hunger,
satiety, and the need to defecate. Its
silent working is governed by the
enteric nervous system (ENS) with its complex network of nerves, hormones, and
neurotransmitters substances. As the ENS ( gut brain) is intricately connected
with the central nervous system or brain, the mechanisms are in place for the
brain to sense events in the gut and to alter gut function. Many famous
physiologists have studied the effects of emotion on the gut, and it is
pertinent to review some of their observations.
Recent research
studies that the disease like Parkinson's
could actually lie in the gut. The first detailed description of
Parkinson's disease published in 1817 by British physician James Parkinson, is
a harrowing read. Based on his observation of six cases, Parkinson found that a
patient starts by experiencing a slight sense of weakness and some bothersome
trembling in one of their hands. The condition slowly worsens to the point
where tremors become more frequent. Simple actions such as walking and eating
become challenging to the point where assistance is needed. After several
years, the patient loses all voluntary
muscle control and requires around-the-clock care. It has been more than 200
years since Parkinson's essay on the "shaking palsy" as he called it.
Yet, the disease bearing his name still has no cure, and why some people get
it, and others don't, has remained a
mystery. Physicians and researchers hope that the latest studies on the
gut will bring more light to the
"unknowns" of other diseases.
Peer-reviewed medical
journals have published case studies by clinical physicians on the subject.
Here's one that even though Dr. Kumamoto and I never submitted it to the
Journals, it's a case worth mentioning. Eighteen years ago, I suddenly found
myself burping not only when I was thirsty (normal) and when stomach was
signaling that it was empty ( normal),
but also at odd moments -- when I was physically tired and mentally
distressed. During that time, I was very fortunate to have several gerontologists from Japan in my tutoring sessions. When I
broached the subject with Dr. Kensuke Kumamoto, he started asking me questions:
how did I respond to stress etc. Did I have a headache? Did I scream at people
when I was angry and frustrated? I said No to both questions. He then said, "yes I have observed that
about you -- you never show your disappointment nor exhibit anger. We never
know when you are frustrated. I presume your burps are your physiological
response to mental stress, physical fatigue which is rather unusual."
Simply put, I burp instead of getting angry at someone who gives me
frustration. Burping was my physical reaction/response to fatigue. My
"official" gastroenterologist prescribed PPI ( proton pump inhibitor)
such as prilosec and prevacid (over the counter drugs) to reduce production of
acid in my stomach. That's the typical prescription when one is afflicted with
heartburn and burping. I was burping but I didn't have heartburn. So of course
taking the PPI was not the solution. Unfortunately, many gastroenterologists
often make the wrong diagnosis because they seem to assume that burping is
always equated with heartburn. They never probe what other symptoms the patient
may be experiencing. Fortunately, I had someone who took time to understand what
my body was going through. Dr. Kumamoto
suggested that I keep a journal on those periods of burps. He and I did
our own "experiments" for several months. And as he initially suspected, my burps were linked
to my brain. Such a conclusion enabled me to manage my situation without
medication.
The Bard of Avon,
William Shakespeare had something to say as well.
"How tartly that
gentleman looks!
I never can see him,
but I am
Heartburned an hour
later"
Certainly, Shakespeare
recognizes the effect of emotion on the esophagus. Anxiety or fear are
aggravating factors to many. As with all the syndromes of the irritable gut, a
sufferer's psychological status is important in the manifestations of symptoms.
Even the self-confident Beatrice in "Much Ado" experienced heartburn
when she was distressed.
In conclusion, we must
recognize thar life's stresses may aggravate or precipitate some gut reactions.
Regular exercise is often helpful, especially if it brings enjoyment. Whatever
the cause ( or causes) of the irritable gut eventually turns out to be, it is
necessary to find what lifestyle changes
are appropriate, and to avoid tests, drugs, or nostrums that may, in the end,
do more harm than the symptoms they are supposed to cure.
Noralyn Onto Dudt is now retired but she tutored
medical doctors who conducted medical research at the National Institutes of Health in Bethesda, Maryland
for about 40 years. Many countries like Japan, Germany, South Korea, France send their doctors to the
National Institutes of Health for a 2 or 3 year-medical research/studies.