View Products for Gastrointestinal Support / Digestion
The mouth, pharynx, esophagus, stomach, small intestines and large intestines make up the digestive tract. Organs that are not in the digestive tract but help in digestion are the teeth, tongue, salivary glands, liver, gall bladder and pancreas. The various organs are depicted in Figure 1.
There are four stages to food processing:
The teeth aid in digestion by cutting, tearing, crushing and grinding food. The salivary glands produce and secrete saliva into the oral cavity. The three salivary glands are the parotid (beneath the cheeks), the submaxillary (below the jaw bone) and the sublingual (below the tongue). Saliva moistens the food and contains enzymes, one of which is salivary amylase, which begins digestion of starch into smaller polysaccharides. The locations of the salivary glands are depicted in Figure 2.
Digestive Enzymes
Throughout the digestive system, enzymes break down food into useful substances.
The enzymes are protein catalysts; they speed up chemical reactions.
The substance that an enzyme acts on is called its substrate.
Enzymes are contained within the digestive juices that are secreted into the digestive tract by exocrine glands. This is in contrast to endocrine glands, which secrete substances directly into the bloodstream.
The exocrine glands that play an important role in the digestive system are the:
Saliva is produced by the salivary glands. It contains mucus and the enzyme salivary amylase.
Salivary amylase breaks down starch into maltose (a disaccharide) as noted in Figure 3. Disaccharides are created when two simple sugars combine.
Mastication and Swallowing
The process of chewing or mastication requires coordination of the chewing muscles, the cheeks, the palate and the tongue. Chewing is normally a reflex action. The forces involved in grinding and cutting the food are enormous, and sufficient to fragment cellulose membranes. Finally, the food is mixed with saliva and formed into a bolus. The bolus is pushed back into the pharynx, when the tongue is pressed against the hard palate.
Swallowing (deglutition) begins as a voluntary process by which the tongue pushes a portion of the food back against the soft palate. Elevation of the soft palate closes the nasopharynx; the food enters the pharynx; the larynx is elevated, closing the epiglottis; and respiration stops. The upper pharyngeal constrictor contracts, initiating sequential contractions of the other pharyngeal constrictors. These contraction waves are involuntary and push the food toward the esophagus. Peristalsis in the esophagus is started as the pharyngeal wave passes through the upper esophageal sphincter. When the propulsive wave reaches the lower esophageal sphincter (LES), the relaxed muscle wall preceding the bolus momentarily relaxes the LES, and the food passes the cardia to enter the stomach. Vagal stimulation relaxes both sphincters.
http://www.zuniv.net/physiology/book/chapter22.html
Figure 4 below demonstrates the location of the upper and lower esophageal sphincters.
The different parts of the stomach are depicted in Figure 5.
The gastric glands in the stomach wall produce gastric juice, which contains:
Pepsinogen is activated by the hydrochloric acid, which converts it into pepsin.
Pepsin converts proteins into peptides (a compound consisting of two or more amino acids linked in a chain), as noted in Figure 6.
Parietal cells are the epithelial cells that secrete hydrochloric acid (HCl) and intrinsic factor. These cells are located in the gastric glands found in the lining of the fundus and in the body of the stomach.
Figure 7 demonstrates the location of the chief cells that produce pepsinogen, which is contrverted to pepsin by hyrocloric acid (HCL), produced by the parietal cell.
Acid secretion is initiated by food: the thought, smell, or taste of food affects vagal stimulation of the gastrin-secreting G cells located in the distal one-third (antrum) of the stomach. (See Figure 7.) The arrival of protein to the stomach further stimulates gastrin output. Acid is secreted by parietal cells in the proximal two-thirds (body) of the stomach. The acid kills off any invading bacteria or viruses. Gastric acid aids digestion by creating the optimal pH for pepsin and gastric lipase and stimulating pancreatic bicarbonate secretion. Circulating gastrin triggers the release of histamine from enterochromaffin-like cells in the body of the stomach. Histamine stimulates the parietal cells via their H2 receptors. The parietal cells secrete acid, and the resulting drop in pH causes the antral D cells to release somatostatin, which inhibits gastrin release (negative feedback control).
The small intestines are 20 feet, a coiled tube beneath the stomach that has three parts:
Figure 9 shows where the small intestine lies in relation to the rest of the digestive system.
The journey through the small intestine takes about 4-8 hours to complete. Digested nutrients are absorbed through intestinal walls. Absorbed materials cross the mucosa into the blood and are transported to other parts of the body for storage or further chemical change.
Pancreatic juice is produced by the exocrine glands (duct cells and acinar cells) in the pancreas. See Figure 10.
The pancreas contains:
Pancreatic amylase carries out the same reaction as salivary amylase, as shown in Figure 11. [FiF]
Pancreatic lipase breaks down triglycerides into glycerol and fatty acids, as shown in Figure 12.
The breakdown of lipids by pancreatic lipase poses special problems, because lipids are insoluble in the aqueous environment of the digestive tract.
As food travels through the digestive tract, the lipids within them melt and coalesce into large droplets.
Lipase is water-soluble, so it’s unable to enter the lipid droplets and will only be able to break down the lipids on the surface of the droplets. Food does not remain in the digestive tract long enough for lipase to be able to completely digest the lipids in this manner.
Bile, produced in the liver but stored in the gall bladder, enters through the bile duct, as shown in Figure 13. It breaks down fats.
Bile molecules have a hydrophobic end (tending to repel or fail to mix with water) and a hydrophilic end (having a tendency to mix with or dissolve in water), so they are able to interact with both the lipids and the water, causing the lipids to break up into smaller droplets. This process, called emulsification, speeds up the digestion of the lipids in the small intestine.
Trypsinogen is activated by an enzyme called enteropeptidase, which is secreted by the lining of the small intestine. Enteropeptidase converts trypsinogen to trypsin.
Trypsin continues the breakdown of proteins, as shown in Figure 14.
Glands in the wall of the small intestine produce enzymes such as maltase (a disaccharide), which breaks down maltose into two glucose molecules, as shown in Figure 15.
Digestive Enzymes
Enzymes produced by the wall of the small intestine are not secreted like the other enzymes of the digestive tract. Instead, they remain attached to the plasma membrane of the cells lining the intestine, with their active sites exposed to the food in the intestine. With this arrangement, the substrates can be digested and then the products of digestion can immediately be absorbed into the body.
Humans can’t digest some macromolecules, such as cellulose because we don’t have the gene that produces the enzyme cellulase.
Control of Digestive Juice Secretion
Nerves and hormones regulate the secretion of digestive enzymes. Nerves carry signals to and from the brain and cause specific responses throughout the body. Hormones are chemical regulators that are secreted in one part of the body (by endocrine glands) and transported by the bloodstream to another part, where they cause a response.
The sight or smell of food causes the brain to send nerve impulses to the stomach to start secreting gastric juices. Much more gastric juice is secreted once food enters the stomach. Receptors in the stomach lining send impulses to the brain, which sends more impulses to the exocrine gland cells and endocrine glands in the stomach wall — and the hormone gastrin is released into the bloodstream. Gastrin travels to the upper part of the stomach, where it stimulates increased secretion of hydrochloric acid.
Large Intestines (Colon)
The colon has a large diameter, but a short length (5 feet).
Water is absorbed from undigested food, making the waste harder until it becomes solid. Waste stays in the colon for 10-12 hours.
The large intestine (or colon) is used to absorb water from the waste material left over and to produce vitamin K and some B vitamins using the helpful bacteria that live there.
All leftover waste is compacted and stored at the end of the large intestine, called the rectum.
When full, the anal sphincter loosens and the waste, called feces, passes out of the body through the anus.
The Big Picture
The endocrine, nervous, digestive and circulatory systems work together to control digestion. Before we eat, smelling food releases saliva in our mouth and gastrin in our stomach, which prepares the body for a snack.
A large meal activates receptors that churn the stomach and empty it faster. If a meal is high in fat, digestion is slowed, allowing time for the fat to be broken down. Thus, this is why we feel fuller after eating a high-fat meal.
The following excerpt is from the book, Brain Maker, by David Perlmutter, M.D. I consider it a must-read.
“Right now, your body is colonized by a multitude of organism that outnumber your own cells by a factor of about ten. These roughly hundred trillion invisible creatures — microbes — cover your insides and outsides, thriving in your mouth, nose, ears, intestines, genitalia, and on every inch of your skin. If you could isolate them all, they would fill up a half-gallon container. Scientists have so far identified some 10,000 species of microbes, and because each microbe contains its own DNA, that translates to more than eight million genes. In other words, for every gene in your body, there are at least 360 microbial ones. Most of these organisms live within your digestive tract, and while they include fungi and viruses, it appears that the bacterial species that make their home inside you dominate and take center stage in supporting every conceivable aspect of your health. And you interact not only these organisms but also with their genetic material.
“It’s now undeniable that our intestinal organisms participate in a wide variety of physiologic actions, including immune system functioning, detoxification, inflammation, neurotransmitter and vitamin production, nutrient absorption, signal being hungry or full, and utilizing carbohydrates and fat. All of these processes factor mightily into whether or not we experience allergies, asthma, ADHD, cancer, diabetes or dementia. The microbiome affects our mood, libido, metabolism, immunity, and even our perception of the world and the clarity of our thoughts. It helps determine whether we are fat or thin, energetic or lethargic. Simply put, everything about our health — how we feel both emotionally and physically — hinges on the state of our microbiome. It is healthy and dominated by so-called friendly, beneficial bacteria? Or is it sick and overrun by bad bacteria?”
Effective in breaking down gluten in the intestines when one has been exposed inadvertently to gluten.
Supports healthy bowel movements.
A combination of herbs that is effective in management of bacterial, yeast, and parasitical intestinal infections.
Provides hydrochloric acid to help maintain gastric pH. Contains factors to promote healthy digestion, especially of dietary protein. Supports absorption of certain macro- and micronutrients. Helps maintain normal gastric flora.
Supports healthy digestion of macronutrients and enhances nutrient absorption. Supports breakdown of polysaccharides in beans and cruciferous vegetables. Helps support pancreatic and brush border enzyme function. Supports breakdown of lactose.
GlutAloe G.I. contains four unique products including L-Glutamine, Licorice Root Extract 10:1 (deglycyrrhized), Arabinogalactan and Aloe Leaf Extract. The combination of these compounds will support the gastrointestinal tract and enhance the production of short chain fatty acids. Heals the gut.
MicroBiome Acute features a diverse blend of HOWARU® and FloraFIT® probiotic strains to support a healthy gut microbiome. With the 18 different strains of health-promoting bacteria provided in MicroBiome Acute, the impact on multiple body systems and functions—such as on immunity, digestion, metabolism, and cytokine production—is maximized because different strains have slightly different functions and are concentrated in various places along the digestive tract. Using a variety of strains also mimics a healthy diet that includes foods containing live and active bacterial cultures, such as fermented foods.
Micro-Biome Complete DF is a vegetarian, dairy- and gluten-free, four-strain probiotic totaling 100 billion CFU† per capsule. Each vegetarian capsule is sealed in nitrogen-purged aluminum blister packs to serve as protection from factors proven to compromise the stability of probiotics such as heat, moisture, and oxygen. Micro-Biome Complete DF provides four researched strains of beneficial bacteria, including the extensively studied HN019 strain of Bifidobacterium lactis. These live microorganisms have proven health benefits and well-established safety, and have been tested for epithelial cell adhesion and/or resistance to low pH.
Micro-Biome Daily DF is a vegetarian, dairy- and gluten-free, four-strain probiotic totaling 30 billion CFU† per capsule. Each vegetarian capsule is sealed in nitrogen-purged aluminum blister packs to serve as protection from factors proven to compromise stability of probiotics such as heat, moisture, and oxygen. Micro-Biome Daily DF provides four researched strains of beneficial bacteria, including the extensively studied HN019 strain of Bifidobacterium lactis. These live microorganisms have proven health benefits and well-established safety, and have been tested for epithelial cell adhesion and/or resistance to low pH.
Dr. Douglas Hall, was born in Indianapolis, Indiana on Jan. 30, 1941. He received his BS and Doctor of Medicine at the University of Florida, training in obstetrics and gynecology. Dr. Hall has been in private practice since 1974 and currently has a large practice in Ocala, specializing in OB/GYN and Functional Medicine.
