Digestion; The oral cavity and Stomach

Question 1

Oral cavity

Answer 1

The oral cavity is the first location in the gastrointestinal tract (GIT) where digestions occurs.

• Chewing breaks down food into smaller chunks and triggers the salivary glands to release saliva containing the enzyme amylase, which breaks down starch
• Food should be chewed up to 20 times per bite. The more you chew, the more amylase is released and the more carbohydrates can be broken down and made available to the body
• Avoid drinking with meals as it dilutes saliva and gastric juices. Less concentrated digestive juices result in fewer nutrients being made available to the body
  Masticate = to chew. Greek – mastichan to gnash, chew

Question 2

Oral cavity:
Salivary Amylase

Answer 2

• Salivary amylase starts breaking down long carbohydrate chains (Polysaccharides), found in starchy foods, into smaller sugar chains. They are fully digested in the small intestine. If you leave starch in your mouth is long enough, you will taste sweetness
• The optimal pH for salivary amylase to function is 6.8 (almost neutral). Amylase is denatured by stomach acid and becomes inactive once the bolus arrives in the stomach
• Carbohydrates not adequately digested in the mouth might remain unutilized by the body as the small intestine can only absorb single sugars
  Amylase = carbohydrate digesting enzyme. Amylo- (starch) + -ase (enzyme)

Question 3

Oral cavity:
Saliva pH

Answer 3

The optimal saliva pH can be challenged by a more acidic environment in the mouth.
* Excess acidity in body tissues will be excreted via saliva, lowering its pH. This impairs the functionality of ‘salivary amylase’ and, therefore, impacts the digestion of carbohydrates in the oral cavity, reducing their utilization in the body.
* The pH in the mouth can be lowered by factors such as refined sugars, meat and dairy, as well as processed foods, chewing down, cigarettes, coffee and alcohol, chronic stress and being sedentary. Exposure to heavy metals from sources such as dental amalgams lowers the pH in the mouth too

Question 4

Stomach: Bolus

Answer 4

The bolus enters the stomach through the lower oesophageal sphincter. The sphincter acts as a seal to prevent acid reflux into the oesophagus
* Food stretches the stomach, which results in the release of the hormone gastrin and the stimulation of the enteric nerves in the stomach wall
* Both stimulate the peristalsis of the stomach leading to the release and formation of gastric juice containing hydrochloric acid (HCl) and the digestive enzymes (lipase and pepsinogen)
* The stomach churns the bolus, mixing it with the gastric juice to break down food
Enteric = intestinal (relating to the GIT)

Question 5

Stomach: Enzymes

Answer 5

Two enzymes are released from the stomach wall (from the chief cells):
1. Pepsinogen
2. Gastric Lipase

Question 6

Stomach enzymes: Pepsinogen

Answer 6

Pepsinogen: An inactive enzyme which becomes active when exposed to HCl. Pepsinogen converts to the active form ‘pepsin’ which breaks down proteins into smaller protein chains

Question 7

Stomach enzymes: Gastric lipase

Answer 7

Gastric lipase: Breaks down lipids (Fats)

Question 8

Stomach: Absorption / portal vein

Answer 8

The stomach absorbs some water, alcohol, iodine and fluoride. These substances enter the venous circulation and are escorted directly to the liver by the ‘portal vein’ to be processed

Question 9

What Enzymes break down Macronutrients?

Answer 9

Amylase = Breaks down Carbohydrates
Pepsin = Breaks down Proteins
Lipase = Breaks down Fats

Question 10

Stomach acid – pH and co factors

Answer 10

Hydrochloric acid (HCl) has a pH of 2 – 3
* Zinc, Vitamin B6 (And to some extent vitamin B1 (Thiamine)) are required to produce HCl

Question 11

Stomach acid:
Zinc Sources

Answer 11

Zinc sources = Nuts, seeds (Especially pumpkin seeds), Eggs, oysters, fish and meat

Question 12

Stomach acid:
Vitamin B6 sources

Answer 12

Vitamin B6 sources = Whole grains, sunflower seeds, legumes, walnuts, green vegetables, carrots, potatoes, avocado, fish

Question 13

Stomach acid:
Actions / functions

Answer 13

Stomach acid performs the following actions:
* Breaks down protein (pepsin) and fats (lipase)
* Triggers pancreatic juice and bile released into the duodenum (via CCK) when the acidic chyme when enters the small intestine
* Eliminates microorganisms such as bacteria, viruses and fungi, protecting against infection
Pepsin = protein-digesting enzyme. Greek pepsis- digestion’ + -in- protein enzyme
Cholecystokinin (CCK) = a hormone released from the duodenum wall

Question 14

Lower stomach acid: Causes

Answer 14

Low HCl production in the stomach can because by:
* Chronic stress (Excess sympathetic activity – Slows down enteric N.S activity = decreases release of stomach juices / peristalsis)
* Low vitamins B6 and zinc (and B1)
* Autoimmune gastritis (can damage parietal cells = affect HCL synthesis)
* Medications (such as protein pump inhibitors – protein = hydrogen. Block hydrogen pumps = fluoride has nothing to bind to = no hydrochloric acid)
* Chronic helicobacter pylori infection (a Bacterium associated with gastritis, peptic ulcers and gastric cancer)
* Ageing (production of HCl gradually declines over the age of 50)
* Vegans/vegetarians may have more difficulty breaking down proteins (not use to) = lower stomach acid levels

Question 15

Low stomach acid: Results

Answer 15

Low HCl leads to poor protein digestion, resulting in protein putrefaction in the small intestine
* Protein putrefaction creates compounds called ‘polyamines’ which are implicated in colorectal cancer
* Undigested food allows bacteria to proliferate in the small intestate (where they would not normally resided large numbers) = small intestinal bacteria overgrowth (SIBO)
* Reduced gastric activity results in less intrinsic factor (a glycoprotein secreted in the stomach), compromising B12 absorption (I.F binds onto B12 ingestedin food and then it is absorbed in the ileum)
* Low HCl can lead to dysbiosis, imbalance of that bacteria, candida, heartburn/reflux
* Deficiencies - Iron and calcium require HCl to ionize/be absorbed
Putrefaction = Decay or rotting

Question 16

Low stomach acid:
Presentation

Answer 16

• Bloating, belching and flatulence within 1 to 2 hours after meals
• Abnormal pain and ‘fullness’ after eating, with foul smelling stools.

Question 17

Stomach acid:
How to increase

Answer 17

• Apple cider vinegar in a little water before meals
  o With the mother = unfiltered/unpasteurized, rich in probiotics
  o ACV = Rich in malic acid (catalyst in Kreb cyscle = increased production of energy) and also used for bile production.
  o Caution = high in histamine
• Bitter herbs and foods stimulate stomach acid release. They should be taken 15 to 20 minutes before meals. These include: gentian, Barberry bark, Andrographis, dandelion and goldenseal. Also include bitter foods such as rockets, chicory, artichoke and watercress
• Zinc and B6 rich foods
• Avoid over-eating and ensure meals are relaxed (eat mindfully). Avoid processed foods
• Eat a diet rich and fruit and vegetables
• Eat fermented vegetable such as sauerkraut and kimchi
• Himalayan and sea salt provide the chloride for HCl
• Supplementation – only after the above steps. Does not address root cause

Question 18

Stomach acid:
Bitters;
(not in exam)

Answer 18

Gentian = Master bitter:
* Extremely bitter, founded in Swedish bitters.
* Caution: Not to use in hyperacidity or ulceration
Barberry bark:
* Energetically - Cooling/clearing heat
* increases digestive secretions
* Helps with dysbiosis
* Laxative – stimulate bile and peristalsis
* Contains Berberine = antimicrobial – helps with dysbiosis, SIBO, insulin resistance
Artichoke:
* Secrete stomach acid and bile
* Lowers cholesterol
Dandelion:
* Stimulates digestive juices in GIT and peristalsis
* Is a diuretic = route of elimination through kidneys
Golden seal:
* Contains Berberine = antimicrobial – helps with dysbiosis, SIBO, insulin resistance
Energetically, Bitters are cooling and so may not be suitable for some constitutions – use warming instead e.g. ginger, Cardamon, fennel, cayenne

Question 19

H. pylori tests

Answer 19

H. pylori Breath test – tests for ammonia
H. Pylori stool test – Test for antigens and is a more comprehensive test for digestive issues

Question 20

H. pylori antimicrobials

Answer 20

• Mastic gum (grease)
• Licorice Root
• Biocidin (Brioad spectrum antimicrobial)
• Probiotics
• Broccoli sprouts (living enzymes, nutritive)
• Algaes
• Salmon (pigment)

Question 21

Cholecystokinin (CCK)

Answer 21

As chyme is ‘Drip fed” through the pyloric sphincter into the duodenum, CCK is released
* CCK: A hormone released from the duodenal wall, triggering the release of pancreatic juice and bile
* CCK also induces a sense of satiety (fullness)
* The initial presence of the acidic chyme in the duodenum is a key factor CCK release, meaning that low stomach acid can ultimately significantly impair digestion
* Chyme has a pH of about 2, it is usually acted upon quickly by bicarbonate, which is secreted by the pancreas and liver. This neutralizes chyme and creates a pH of about 6.5 in the duodenum
Chole = bile, cysto = sac (gall bladder), kinin = move
Chyme = semi-fluid mass of partly digestant food, expelled by the stomach