The Digestive System Overview

The four steps to the digestive process are ingestion, mechanical and chemical breakdown of food, nutrient absorption and elimination of indigestible food through excretion. The gut is one of the core disease-fighting systems of the human body. First, the acid and enzymes in the stomach work to sterilize our food and, in this way, protect the body from illness and infection. In addition, the digestive tract is an important source of immune function in the body. With 80 percent of our immune system residing there, the state of our gut helps determine how we feel, physically and mentally, most days.

Accessory Organs to the Digestive System

The salivary glands, liver and gall bladder, and the pancreas aid the processes of ingestion, digestion, and absorption. These accessory organs of digestion play key roles in the digestive process. Each of these organs either secretes or stores substances that pass through ducts into the alimentary canal. Accessory organs add secretions and enzymes that break down food into nutrients. The secretions of the liver, pancreas, and gallbladder are regulated by hormones in response to food consumption. Chemical digestion in the small intestine relies on the activities of three accessory digestive organs: the liver, pancreas, and gallbladder.

The Importance of Enzymes

Enzymes help speed up chemical reactions in the human body. They bind to molecules and alter them in specific ways. They are essential for respiration, digesting food, muscle and nerve function, among thousands of other roles. Our bodies naturally produce both digestive and metabolic enzymes, as they are needed. Enzymes are protein chemicals, which carry a vital energy factor needed for every chemical action, and reaction that occurs in our body.

There are approximately 1,300 different enzymes found in the human cell. When we consume food, our body produces saliva, a digestive juice, which helps to moisten the food we eat for easy movement through the esophagus into the stomach. Saliva contains an enzyme that begins to break down starches in our food as our teeth break food down into smaller bites.

Enzymes catalyze all kinds of chemical reactions that are involved in growth, blood coagulation, healing, diseases, breathing, digestion, reproduction, and many other biological activities. On biological aspects, enzymes are instrumental substances to many functions in living organisms.

The three main enzymes that can break down different nutrients include:

• Amylase and other carbohydrase enzymes break down starch into sugar.
• Protease enzymes break down proteins into amino acids.
• Lipase enzymes break down lipids (fats and oils) into fatty acids and glycerol.

Other Enzymes are:

• Acetylcholinesterase – breaks down the neurotransmitter acetylcholine in nerves and muscles.
• Amylase – helps change starches into sugars. Amylase is found in saliva.
• Chymotrypsin – a digestive enzyme which breaks down proteins in the small intestine. It is secreted by the pancreas and converted into an active form by trypsin.
• Polymerase – synthesize DNA from deoxyribonucleotides.
• Lactase – also found in the small intestine, breaks lactose, the sugar in milk, into glucose and galactose.
• Lipases – a group of enzymes that help digest fats in the gut.
• Maltase – also found in saliva; breaks the sugar maltose into glucose. Maltose is found in foods such as potatoes, pasta, and beer.
• Pepsin – responsible for breaking down proteins into peptides. This activation sets up a chain reaction that produces more pepsin, allowing for better protein digestion.
• Lipases – a group of enzymes that help digest fats in the gut.
• Proteolytic enzymes – three main proteolytic enzymes produced naturally in your digestive system are pepsin, trypsin and chymotrypsin. Your body produces them to help break down dietary proteins like meat, eggs and fish into smaller fragments called amino acids.
• Serrapeptase – used for painful conditions including back pain, osteoarthritis, rheumatoid arthritis, osteoporosis, fibromyalgia, carpel tunnel syndrome, migraine headache, and tension headache.
• Trypsin – found in the small intestine, breaks proteins down into amino acids.

Enzyme Deficiency & Dysfunction

The American diet is generally enzyme-deficient because most of the food we consume has been cooked or processed. Enzymes come from three main sources: plants, animal products and microorganisms. Humans have herbivore digestive systems, so we require a majority of plants in our diet.

Foods, such as mushrooms and root vegetables, provide microorganisms and that’s where we get our B-vitamins. We can consume some meat, but we don’t have the same digestive enzymes as carnivores to break it down effectively. It takes the human digestive system approximately 20-40 min. to absorb nutrients, while meat (depending on the type) can take 24-72 hours to break down.

Symptoms of enzyme deficiency may include lack of muscle coordination, brain degeneration, learning problems, loss of muscle tone, increased sensitivity to touch, spasticity, feeding and swallowing difficulties, slurred speech and an enlarged liver and spleen. A variety of conditions can damage your pancreas and lead to exocrine pancreatic insufficiency (EPI). Some of them, such as pancreatitis, cause EPI by directly damaging the pancreatic cells that make digestive enzymes. Inherited conditions such as Shwachman Diamond syndrome and cystic fibrosis can also cause EPI, as can pancreatic or stomach surgery.

Enzyme-rich Foods

Foods that contain natural digestive enzymes include pineapples, papayas, mangoes, honey, bananas, avocados, kefir, sauerkraut, kimchi, miso, kiwifruit and ginger. Adding any of these foods to your diet may help promote digestion and better gut health.

Raw fruits and vegetables grown in nutrient-rich soils already contain the enzymes needed for us to digest the plants’ proteins and carbohydrates. Fruits and vegetables with the most enzymes when eaten raw include papayas, mangoes, pineapples, apples, avocados, carrots, grapefruit, spinach, and tomatoes. All forms of life live by enzymes and also produce enzymes. As a result, enzymes can be obtained from three different sources: plants, animals, and microorganisms.

Some enzymes such as papain, bromelain (bromelin) ficin, and malt diastase are derived from plant sources. Proteolytic enzymes have many important functions in the body, including helping break down food for energy, and are found in certain foods and supplements. Studies suggest that they can improve digestion, decrease inflammation, ease arthritis pain and possibly reduce symptoms related to IBS.

Enzyme Cofactors

Some enzymes cannot function unless they have a specific non-protein molecule attached to them. These are called cofactors. For instance, carbonic anhydrase, an enzyme that helps maintain the pH of the body, cannot function unless it is attached to a zinc ion. Coenzymes and cofactors are molecules that help an enzyme or protein to function appropriately.

Coenzymes are organic molecules and quite often bind loosely to the active site of an enzyme and aid in substrate recruitment, whereas cofactors do not bind the enzyme. A cofactor is a non-protein chemical compound or metallic ion that is required for an enzyme’s activity as a catalyst, a substance that increases the rate of a chemical reaction. Cofactors can be considered “helper molecules” that assist in biochemical transformations.

While enzymes are proteins, coenzymes are small, non-protein molecules. Coenzymes hold an atom or group of atoms, allowing an enzyme to work. Examples of coenzymes include the B vitamins and S-adenosyl methionine. Magnesium is a cofactor for several important enzymes in the body, like DNA/RNA polymerases, used to transcribe new DNA/RNA strands, and guanylate cyclase, used to regulate the movement of minerals across cell membranes.

A 1968 estimate suggested that magnesium was a required cofactor for 300 enzymatic reactions. Metal ions are common cofactors. The study of these cofactors falls under the area of bioinorganic chemistry. In nutrition, the list of essential trace elements reflects their role as cofactors. In humans this list commonly includes iron, magnesium, manganese, cobalt, copper, zinc, and molybdenum. When enzymes denature, they are no longer active and cannot function. Extreme temperature and the wrong levels of pH — a measure of a substance’s acidity or alkalinity — can cause enzymes to become denatured.d our body from the food, water, personal-care products, etc. Cancer is a highly destructive mega-event occurring inside the body. Your body pH is acidic. It needs to be alkaline. Ideal body pH is 7.25-7.5.