Why do we
get butterflies in our stomach before a performance?
indigestion produce nightmares?
antidepressants now also being used for gastrointestinal ailments?
It turns out that both our gut and our brain
originate early in embryogenesis from the same clump of tissue which divides
during fetal development. While one section turns into the central nervous
system, another piece migrates to become the enteric nervous system. Later the
two nervous systems connect via a cable called the vagus nerve -- the longest of
all the cranial nerves whose name is derived from Latin, meaning
"wandering." The vagus nerve meanders from the brain stem
through the neck and finally ends up in the abdomen. There's the brain-gut
Have you ever wondered why an impending job
interview can cause an attack of intestinal cramps? And why do anti-depressants
targeted for the brain cause nausea or abdominal upset in millions of people who
take such drugs? The reason for these common experiences is because each of us
literally has two brains --the familiar one encased in our skulls and a
lesser-known but vitally important one found in the human gut. Like Siamese
twins, the two brains are interconnected; when one gets upset, the other does,
too. No wonder people trust their gut. One half of all our nerve cells are
located within the gut.
The state of the gut has a profound influence
upon our health. It is from the healthy gut that we enjoy neurological and
psychological as well as immunological health. This is not to discount the human
brain. This is simply to say that the body has two brains -- the second brain
being our gut. There is an excellent article on this brain-gut connection called
Complex and Hidden Brain in Gut Makes Bellyaches and Butterflies written
by Sandra Blakeslee, originally published in the January 23, 1996 issue of The
New York Times.
brain, known as the enteric nervous system (ENS), is located in sheaths of
tissue lining the esophagus, stomach, small intestine and colon. Considered a
single entity, it is packed with neurons, neurotransmitters and proteins that
zap messages between neurons or support cells like those found in the brain. It
contains a complex circuitry that enables it to act independently, learn,
remember and, as the saying goes, produce gut feelings.
In his book The Second Brain, HarperCollins
1998, Dr. Michael Gershon, a professor of anatomy and cell biology at
Columbia-Presbyterian Medical Center in New York City, dubs the entire
gastrointestinal system the body's second nervous system. "The brain is not
the only place in the body that's full of neurotransmitters," says Dr.
Gershon. "A hundred million neurotransmitters line the length of the gut,
approximately the same number that is found in the brain..." If we add the
nerve cells of the esophagus, stomach and large intestine, there are more nerve
cells in the gut than there are in the entire remainder of the peripheral
nervous system. Nearly every chemical that controls the brain in the head has
been identified in the gut, including hormones and neurotransmitters.
This complex circuitry provides the brain in the gut with the means to act
independently. Proof of this can be seen in stroke victims whose brain stem
cells, which control swallowing, have been destroyed. If this occurs, a surgeon
has to create an opening in the abdominal wall, so that feeding can be
accomplished by manually inserting foods directly into the stomach. Once the
food is in the stomach, digestion and absorption can take place, even in
individuals who are brain dead. The central nervous system is needed for
swallowing and for defecation, but from the time the food is swallowed to the
moment its remains are expelled from the anus, the gut is in charge.
is shed on the circuitry between the two brains, researchers are beginning to
understand why people act and feel the way they do. The brain and gut are so
much alike that during our sleeping hours, both have natural 90-minute cycles.
For the brain, this slow wave sleep is interrupted by periods of rapid eye
movement sleep in which dreams occur. For the gut, the 90-minute cycles also
involve slow waves of muscle contractions but, as with REM intervals, these are
punctuated by short bursts of rapid muscle movement. Could it be that both
brains influence each other? The answer is probably yes. REM sleep is a sleep
phase characterized by arousal, altered activity of the autonomic nervous system
and altered colon (large intestine) function.
We also know that patients with bowel problems
tend to have abnormal REM sleep. Poor sleep has been reported by many perhaps a
majority of, patients with irritable bowel syndrome (lBS) and non-ulcerative
dyspepsia (also known as "sour stomach") who complain of awakening
tired and unrefreshed in the morning. Even after patients awake from what they
describe as a "sound sleep," they report a general feeling of
tiredness and fatigue.
Abnormal REM sleep is reduced by low-dose
treatment with the anti-depressant amitryptiline, which has also been shown to
be effective in treating lBS and non-ulcerative dyspepsia. Many drugs designed
to affect the brain also affect the gut. For example, the gut is loaded with the
neurotransmitter serotonin. In fact, more serotonin is produced there than
anywhere else in the body. Serotonin is linked with initiation of peristalsis.
of people taking fluoxetine (Prozac) and other types of similar-acting
antidepressants experience gastrointestinal problems such as nausea, diarrhea
and constipation. The problem with these drugs is that they prevent uptake of
serotonin by cells that should be using it. While this enables the depressed
person to have more serotonin in the brain, less is available for use by the
cells of the gastrointestinal tract. "Serotonin is calming to the digestive
tract, initiates peristaltic and secretory reflexes," notes nutritionist
June Butlin, M.Sc., Ph.D. "Long-term use or the wrong dosage may cause
fluctuations between nausea, vomiting, constipation and diarrhea, and can cause
depression, anxiety, insomnia, and fluctuations in appetite."
In a study reported in The New York Times
article, Dr. Gershon and his colleagues explain Prozac's side effects on the
gut. They mounted a section of guinea pig colon on a stand and put a small
pellet in the 'mouth' end. The isolated colon whips the pellet down to the
'anal' end of the column, just as it would inside an animal. When the
researchers put a small amount of Prozac into the colon, the pellet "went
into high gear," Dr. Gerhson explained to the paper. "The drug doubled
the speed at which the pellet passed through the colon, which would explain why
some people get diarrhea," the paper says. No wonder, in small doses,
Prozac is used to treat chronic constipation.
Although a little is beneficial for constipation,
a lot is not. When the Gershon team greatly increased the amount of Prozac in
the guinea pig colon, the pellet stopped moving at all. Hence, a little cures
constipation; a lot causes it. Prozac stimulates sensory nerves, thus can also
The gut has opiate receptors much like the brain.
"Not surprisingly, drugs like morphine and heroin that are thought to act
on the central nervous system also attach to the gut's opiate receptors,
producing constipation," notes pain management specialist Michael Loes,
M.D., M.D.(H.), author of The Healing Response (Freedom Press 2002)
"Both brains," he says, "can be addicted to opiates."
Many Alzheimer's and Parkinson's disease patients
are constipated. A sickness we think of as primarily affecting the brain or
central nervous system also impacts the gut.
Our gut also helps us in some amazing ways. The
gut also produces chemicals called benzodiazepines. These are the same chemicals
found in anti-anxiety drugs like Valium, and these are the same chemicals that
alleviate pain. Perhaps our gut is truly our body's anxiety and pain reliever.
While we are not sure whether the gut synthesizes benzodiazepine from chemicals
in our foods, bacterial actions, or both, we know that in times of extreme pain,
the gut goes into overdrive, delivering benzodiazepine to the brain. The result
is to render the patient unconscious or at least reduce the pain, says Dr.
Anthony Basile, a neurochemist in the Neuroscience Laboratory at the National
Institutes of Health in Bethesda, Maryland.
the world's healing and mystical traditions, the belly is seen as an important
center of energy and consciousness. You've probably noticed that many of India's
great spiritual adepts sport prodigious bellies. These tremendous tummies are
thought to be full of prana. Hence, Indian artists often depict their deities
with a paunch.
In China, the gentle art of tai chi emphasizes
the lower abdomen as a reservoir for energy. Tai chi teacher Kenneth Cohen,
author of The Way of Qigong (Ballantine Books 1997), explains that it's
possible to strengthen the abdominals by learning how to compact qi (prana) into
the belly. "From the Chinese viewpoint," he says, "the
belly is considered the dan tian or 'field of the elixir,' where you plant the
seeds of long life and wisdom."
Lastly, in Biblical times, the seat of emotion,
which we call the heart, is actually referring to the bowels. That thought in
itself conjures up an image of a young Romeo sending a love note to his Juliet
saying, "You move me."
In all seriousness, most people today completely
ignore gut health. As a result, they are experiencing health problems that could
be overcome if they knew that they centered in their gut. So I guess the thing
to remember is, as Dr. Gershon puts it, "Take care of your gut and your gut
will take care of you."
Notes taken from, Patient Heal Thyself by Jordan S. Rubin, NMD,
Health and Wellness Through Education
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