Download Gastrointestinal Function

Gastrointestinal Function
The health of your gastrointestinal (GI) tract largely determines your overall health. It functions to digest, absorb and then finally assimilate the food you eat. As discussed in the Diet section, your food
should be high quality with nutrients available to supply your body with the substrates it needs.
Your GI tract also houses 70% of your body’s immune system. It is the immune system’s first line of
defense against infection or other foreign substances. The acid in your stomach provides an important
barrier to unwanted bacteria, yeasts, viruses and parasites that may come in with food. The mucus secreted in the lower intestine performs a similar function, encasing the problem substance and removing
it with the stool.
Food is made up of carbohydrates, fats and protein. Carbohydrates are your body’s main source of fuel.
Protein is needed for making the essential hormones and enzymes, preserving lean muscle mass, and
for tissue repair. Dietary fat provides energy, maintains cell membranes and helps absorb fat soluble
vitamins. The state of repair of your digestive tract determines how well you break down and take in
these substances so essential for well-being.
Thinking about or smelling food initiates the digestive process by triggering the hormone gastrin that
stimulates the stomach cells. Chewing also initiates chemical reactions that prepare the stomach, gallbladder and pancreas for proper digestion. The esophagus, the tube between your mouth and your
stomach, transports the swallowed food to your stomach. There is a circular muscle at the juncture of
the esophagus and the stomach that should open to let the food pass, and then close to prevent stomach acid or food-stuff from returning back up the throat.
Food in the stomach is churned into a chopped up liquid mash called chyme. In a properly functioning
stomach, gastric juices contain hydrochloric acid, which is important for the breakdown of protein into
peptides, smaller chains of amino acid molecules, in preparation for their absorption. Digestion of the
other materials in the chyme is also stimulated by this acid pH.
The mass of chyme proceeds into the first part of the small intestine, the duodenum, where its acidic pH
stimulates the production of pancreatic juices which are very alkaline. The pancreas releases sodium
bicarbonate along with 22 different digestive enzymes. At this point only a few of the proteins and carbohydrates have broken down, and none of the fats. The pancreatic enzymes trypsin and chymotrypsin
continue to break down protein molecules. Amylase further breaks down starches (carbohydrates) into
maltose. And the fat dissolving enzyme lipase begins to digest fat into glycerol and fatty acids.
The muscular action of the GI tract, peristalsis, is a circular action that moves the chyme down into the
next part of the small intestine, the jejunum. This is where most of the absorption takes place. Enzymes
embedded in the lining of the small intestine complete the digestion of peptides into amino acids and
maltose into simple sugars that are then taken across the cells of the lining of the GI tract into the blood
stream.
The remaining mass of chyme moves into the large intestine. Once in the colon several important
functions take place. The absorption of water and sodium solidifies the liquid mass into a more solid
consistency. The good bacteria in the colon, the intestinal flora, mediate the creation and absorption of
important nutrients. What is left passes out of the body during a bowel movement as stool.
Numerous studies have shown that stomach acid secretion declines with advancing age. Acid chyme
is very important for proper digestion and absorption, as the pancreas will not function to secrete its
digestive juices without the stimulation of acid. If your problem is too little stomach acid, you may feel
food sitting in your stomach for hours after eating, especially after eating protein. You may experience
burping, gastric reflux, lethargy and sleepiness after a high protein meal. Your stool may have a bad
smell, like rotting meat, the smell of putrefaction. Stool should ordinarily have some odor, but not an
unpleasant one. Unpleasant odor implies improper digestion and undigested food passing out in the
stool, taking the nutrients you need along with it.
If you are having trouble digesting protein, you can use hydrochloric acid and the enzymes protease,
trypsin, and pepsin as digestive aids. You need to chew your food very thoroughly as the smaller the
particle of protein, the easier it is to digest. Eating sour foods with the meal, like pickles, or taking 1
ounce of apple cider vinegar in 4 ounces of water may help. You can try eating proteins separately from
the rest of the meal by 15 or 30 minutes. Starches slow down protein digestion, and sugar and desert
stop it immediately by causing premature emptying of the stomach contents into the duodenum where
acid digestion stops. This may reduce the discomfort of undigested protein in your stomach, but your
pancreas can’t do what the stomach was intended to do. For this reason, don’t eat fruit and protein
together.
If you are having problems digesting carbohydrates, grains, starches, fruits, vegetables, and legumes,
you will notice symptoms of indigestion after high carbohydrate meals such as pasta or vegetables.
Your stool will be foul smelling, but in this case, it will have an odor of methane, similar to cow or horse
manure, the smell of fermentation. The digestion of carbohydrates starts in the mouth where salivary
amylase mixes with the food during chewing. Again, the food needs to be chewed thoroughly for optimal digestion. Chewing also stimulates relaxation and sets the proper nervous tone for the GI tract to
function optimally. You can take alkaline foods with your meal like mineral water and salt. And you can
take digestive aids high in amylase.
The digestion of fats starts with the secretion of pancreatic lipase and bile salts from the gallbladder. If
you have a problem digesting fat, you may see oil or globules of fat floating on the water after a bowel
evacuation following a fatty meal. You may try digestive aids high in lipase. If your stool is light colored,
light brown, yellowish, gray or whitish, you may have insufficient production of bile, a clogged bile duct,
or thick, slow moving bile. You may benefit from the use of bile salts with your meal. You may need both
lipase and bile salts. Lipase cannot do what bile salt is needed for, and vice versa.
There is contention over the issue of whether stool should float or not. There are different reasons why
stool may float, some are good and others are not. High fiber content and good bacteria in the stool will
cause it to float. That is not a problem. Stool floating can be from high fat which implies poor fat digestion. Gas and flatulence can build up inside a stool and it will float, but that is also not optimal. If you are
detoxifying, that will impact the stool and change many of its parameters in an unpredictable way.
The right digestive aid can help very quickly, within one week. You may have to try several before you
get the right aid. If you get partial success, you may need to use more. Getting it right with digestive
aids is more of an art than a science. If digestive disturbances are not relieved by digestive aids, it may
be that the organisms in the your GI tract are unbalanced. Candida is a prime suspect and is discussed
in its own section.
Conversely, the stomach can also produce too much acid, or produce it at inappropriate times, leading
to reflux of acid into the throat and/or over acidity in the bowel. Commonly this condition is associated
with other abnormalities of the bowel such as inflammatory disorder, allergic inflammation and chronic
viral infection. These conditions reduce the function and the motility of the bowel. This leads to the
backup of its contents, as opposed to their smooth process out of the body.
Getting the pH of the stool with a stool analysis is important. The pH of the bowel impacts what organisms grow there, and the rate at which important enzymatic reactions take place. Digestive processes
are pH sensitive and will not function optimally at the wrong pH. Acid environments increase inflammation in the GI tract and in the body in general. Inflammation compromises normal absorption of nutrients
across the bowel epithelium. The normalization of the intestinal environment happens over time, with
patience and careful clinical follow up. Your treatment has limited chance for success if your bowel
environment is non-optimal.
There are particular problems which have been defined in the intestinal tracts of children on the autism
spectrum. The small bowel is the most important site of GI disease in this group. The small bowel,
which is described as having three parts, the duodenum, jejunum and ileum, functions to break down
food and absorb the ensuing nutrients. Anyone with small bowel disease will have disturbed digestive
processes and may have low nutrient levels in their body. The symptoms of small bowel problems include stomach pain, diarrhea, constipation, mucus in the stool, nausea, vomiting, right lower quadrant
pain, malabsorption, poor growth, poor appetite, food aversion and low albumin (protein) levels in their
blood.
The terminal ileum is the last few inches of the small bowel. It is important because it is the most immunologically active portion of the small bowel. It is lined with lymph nodes that are part of the immune
system, and that enlarge when they are activated by a noxious stimulus. It is a major site of disease
activity for children on the autism spectrum who have bowel symptoms. Problems can focus there for
others with bowel symptoms as well.
The enlargement is caused by the rapid multiplication of immune cells within the lymphoid nodule. The
stimulus often is a food to which the individual is allergic, a fungus, a bacteria or a virus. The purpose of
those cells is to find whatever it is that is triggering the immune system and eliminate it. Like chronically
inflamed tonsils, once these nodes are swollen, it may not be possible to reduce their size again. Poor
mobility of the small bowel is common in this condition, with consequent upper GI tract symptoms of
gastroesophageal reflux, pain and inflammation, and lower GI tract symptoms of pain, diarrhea, constipation, cramping and poor motility. What is seen on endoscopy has been described as classic allergic
changes in both the upper and the lower GI tract, among other things.
Think of the GI tract as a flexible hose that must contract from its upper end to its lower end. If the hose
becomes swollen so that it looses its contractility and its flexibility, its function is impaired. Impaired
function then impacts GI enzymes important for digestion. The delicate internal environment that the GI
tract must maintain becomes abnormal. The pH may become too acid, which makes the inflammatory
condition worse. Under problem conditions, the cells lining the inside of the tube, the epithelial cells,
become abnormal. They swell and fill with immune cells as the skin does when you have hives. This
loosens up the contact between the walls of the cells of the epithelial lining. These cells may die and
disappear, leaving the surface below raw and exposed. When these cells die, the enzymes of digestion
normally produced by them also disappear. All of these changes allow molecules which the body does
not recognize to come into contact with the blood. This initiates a foreign body reaction to these molecules which is an allergic response. This condition has been described as ‘leaky gut’, which mediates
delayed onset food allergies and is accompanied by a number of symptoms.
Leaky gut is seen in adults as well as children, and there is one other condition which often happens
when leaky gut is present. Between the last part of the ileum and the first part of the colon, there is a
valve called the ileo-cecal valve. With swelling, allergic response and inflammation happening in this
area, that valve can become rigid and fixed in an open position. The valve is intended to keep the contents of the colon that are meant for discharge out of the body, from backing up into the small intestine
that is meant to absorb nutrition. It is as if the contents of the area where the garbage is temporarily
stored were backing up into the kitchen. This can make you very toxic.
Open ileo-cecal valve is usually accompanied by poor intestinal motility. Stool may be difficult to pass
or take many days to come, yet be very soft when it does pass. The entire colon may be filled with soft
stool when seen on x-ray. Impacted stool is hard and when seen on x-ray the colon is usually distended
behind it.
Nancy Mullan MD
2829 Burbank Blvd., Suite 202
Burbank, CA 91505
Telephone: (818) 954-9267
Fax: (818) 954-0620
Email: [email protected]
Web: www.NancyMullanMD.com