Digestion Flashcards
What are the three primary functions of a digestive system?
Digestion (mechanical and chemical), absorption and excretion.
What is the function of the digestive system?
To nourish the cells of the body - supporting cellular processes.
Name the digestive system’s accessory organs?
Salivary glands, pancreas, liver, gall bladder and biliary tract.
What hormone is released with the bolus reaches the stomach?
Gastrin
What do parietal cells produce?
HCL and Intrinsic factor
What does pepsinogen require to convert it to its active form pepsin?
HCL
What do chief cells produce?
Pepsinogen
What does the stomach absorb?
Water, alcohol, iodine and fluoride. Enter venous circulation, directly to the liver via portal vein.
How are low levels of HCL associated with increased risk of colorectal cancer?
Without adequate HCL, the undigested proteins enter the intestine leading to putrefaction and fermentation which can be damaging to the intestinal lining and creates compounds called polyamines (polyamines are molecules involved in cell growth and division) implicated in colorectal cancer.
What co-factors are needed for the production of HCL?
Zinc and B6.
What are the functions of hydrochloric acid (HCL)?
- breaking down proteins and fats
- triggers pancreatic juice and bile release via CCK (stomach acid in the chyme in the duodenum)
- eliminates micro-organisms such as bacteria and viruses due to low pH
What causes low HCL?
SAD HAM
Stress
Ageing
Deficiency - low B6 and zinc
H pylori (chronic)
Autoimmune gastritis
Medications - PPIs
A condition that can result from protein putrefaction in the small intestine?
Small Intestine Bacterial Overgrowth (SIBO) - undigested food allows bacteria to proliferate in the small intestine.
What are the symptoms of low HCL?
Bloating, belching and flatulence.
Abdominal pain.
Fullness after eating.
Foul-smelling stools.
Stools that float.
How to increase stomach acid?
MAZ B
Mindful eating
ACV
Zinc and B6
Bitter herbs and bitter foods
Provide examples of bitter herbs?
Gentian (found in Swedish bitters) barberry bark, dandelion and goldenseal.
Provide examples of bitter foods?
Rocket, chicory, artichoke and watercress.
Name the brush border enzymes?
Maltase, sucrase, lactase and dipeptidase.
How are fat-soluble vitamins absorbed?
Via lymphatic capillaries (lacteals).
What is an exocrine gland?
Secrete their substances via a duct.
What is an endocrine gland?
Secrete their substances directly into the bloodstream.
What is the key exocrine function of the pancreas?
To produce enzymes that digest carbohydrates, proteins and fats. Secreted into the small intestine.
How much ‘pancreatic juice’ is produced daily?
1.2 - 1.5 L/day
Names the pancreatic enzymes?
Pancreatic lipase
Pancreatic amylase
Proteases - trypsin and chymotrypsin
How long is the pancreas? and where is it located?
About 6 inches and sits in the posterior abdomen, behind the stomach. Connected to the duodenum via the pancreatic duct.
Symptoms of poor pancreatic enzyme production?
Bloating, flatulence and abdominal pain, about 1 hour after eating. Lack of digestion can also lead to weight loss.
What causes stools to float?
If fats are not being digested.
Why is over-eating, or eating too often, detrimental?
DOME
- Digestive enzymes are used up
- Organs, such as pancreas and stomach, are placed under stress - constantly needing to produce digestive juices, depleting their capacity.
- Meat - eating too much dense protein such as meat or soya. Increases daily energy expenditure to 50% (in a healthy, well balanced diet - 10%).
- Energy is directed away from healing/repair, increasing risk of disease.
What are the symptoms of an over-burdened digestive system?
Fatigue, reduced immunity, increased acidity.
What did Bernard Jensen advocate?
A bentonite (clay from volcanic ash) bowel cleanse.
Undigested materials would store in the lining of the intestines impairing the absorption and delivery of nutrients. Stuffed colon wall.
These undigested materials would create an optimal environment for parasites and candida to flourish.
Support detoxification for elimination of these wastes.
- Digestive system load should be reduced.
- Intermittent fasting.
- Detoxification.
- Veg broth.
- Chlorophyll.
Where is the gallbladder located? and what does it do?
The gallbladder is located beneath the liver? It stores and releases bile produced by the liver. It releases bile into the small intestine via the common bile duct.
What does bile comprise of?
Mostly water, bile salts, cholesterol and bilirubin.
Gallbladder functions?
Emulsification - breaks into smaller molecules > greater surface area for pancreatic lipase to work on
Detoxification - harmful materials dealt with by the liver are excreted into bile for elimination
Peristalsis - stimulates intestinal peristalsis
Cholesterol - excretes excess cholesterol in the body
Poor bile flow affects fat digestion and the body’s ability to eliminate toxins through the bowel.
Two ways of ensuring adequate production and release of bile and pancreatic juices?
- sufficient water consumption
- good levels of HCL - bitters can help stimulate
How much blood does the liver filter every minute?
1.4 litres
What does the liver store?
Carbohydrates
Fats
Iron
Vitamins ADEK
B12
Which can be released into the blood and made available to cells as required.
What does the tripeptide glutathione comprise of?
Cysteine, glycine and glutamine
What nutrients support phase II liver detoxification?
Sulphur (garlic and onions), magnesium and B vitamins.
Herbs that support liver detoxifcation?
Milk thistle, dandelion root and liquorice root.
Name one factor which reduces the production of IgA?
Stress
What might smelly flatulence or bloating suggest?
That proteins aren’t being digested well in the stomach and small intestine. Proteins are reaching the large intestine where the microflora are fermenting the material and hydrogen sulphide is the by-product.
Functions of microflora
Veg Bring Protective Good Microflora
Vitamins - biotin (B7) and K2
Barrier - intestinal permeability - ingest fibre to make short chain fatty acids (scfa’s) which are used by enterocytes to tighten up the barrier.
Protective against pathogens - out-competes for attachment to the intestinal epithelium eg antibiotics can wipe out the good bacteria leaving space for ‘bad’ bacteria or yeast such as candida to flourish.
GALT - effective functioning of the immune system.
Mood - Bach connection between microflora and mental health, esp depression. Microflora can synthesis neurotransmitters eg bifido bacteria and lactobacillus can produce GABA.
What can damage intestinal permeability?
IF DASH
Inflammation
Food - refined sugars, hydrogenated fats/trans fats, junk foods.
Drugs - corticosteroids: thins the membrane
NSAIDs: inhibit prostaglandins which reduce mucous production and blood flow
Alcohol and smoking
Stress - excessive
Heavy metals
What is the function of prostaglandins?
- creates an inflammatory cascade
- play a role in mucous production in the GIT
- Perfuses the GIT with digestive blood
What is Calprotectin a marker of?
Calprotectin is a protein. A marker of inflammation in the GIT. Often raised in people with Crohn’s and those taking NSAIDs long term.
How can low stomach acid impact microflora?
Low HCL may mean bacteria grows higher up in the digestive tract.
Define ‘dysbiosis’?
An imbalance in the colonies of bowel flora ie an overgrowth of pathological bacteria.
What can dysbiosis be associated with?
Breast cancer eg bacteria able to help process the oestrogen. In a situation of imbalance, the oestrogen is more likely to recirculate.
IBD
Inflammation - lots of pathogenic bacteria will be releasing lipopolysaccharides as they die causing issues with permeability and molecules leaking into the blood.
Reduced immune function - the GALT learns from the microflora.
What foods and herbs can help with dysbiosis?
Garlic - a prebiotic that is great an balancing out the microflora.
Berberine - a constituent of Barberry bark and Goldenseal
Thyme - anti-microbial
What enzyme is used to treat biofilms?
A biofilm is a bacteria that surrounds itself in a casing. Serrapeptase helps to treat these resistant intestinal infections.
Effects of eating junk food
SAD Gut
Spikes in glucose/insulin
Addictive eating
Deficiencies in vitamins and nutrients - craving more - chasing the nutrients/vitamins needed.
Gut dysbiosis - inflammation, leaky gut, reduced immune function
where is the pyloric sphincter?
Between the stomach and the duodenum.
What is the Migrating Motor Complex (MMC)?
Series of nerve signals traveling between the stomach to the terminal ileum causing peristaltic motions through stomach muscle, sweeping residual materials through.
It can also increase gastric, biliary and pancreatic secretions.
How can an impaired MMC contribute to SIBO?
Without the forward motion, microbes from the large intestine can travel in a retrograde manner back through the ileocaecal valve and colonise within the small intestine.
How many stages are there to the MMC and how long does it take?
Four stages, and it takes 1 hr 45 mins.
Ideally MMC needs 4 hours between meals for this to kick in and work.
How to support the functioning of the MMC
Prokinetics (such as ginger or gotu kola)
Bitters
SOD
Stress - reduce! SNS dominance reduces peristaltic motions
Over-eating - need 4-5 hrs between meals
Dense proteins - slows digestion process. Chewing will help!
What is a great laxative?
Aloe vera. Soothing. Soaked linseeds or flaxseeds - very good at dragging the material out of the digestive tube. Also very nutrient dense. Or magnesium citrate - also a muscle relaxant and helps with sleep.
What governs digestion?
The enteric nervous system or the ‘brain of the gut’ extending from mouth to anus.
What are the two nerve plexuses in the enteric nervous system?
Myenteric - m = motility
Submucosal - s = secretions
What effect does the sympathetic nervous system have on the digestive system?
Decreases muscular activity ie. peristalsis. Decreases digestive secretions. Slows everything down.
What is the role of the vagus nerve in the digestive system?
The 10th cranial nerve, extending from the head, travels through the thorax and diaphragm where is innervates the digestive organs - connecting the brain and gut. It directly stimulates the myenteric and submucosal plexus.
Two ways in which we can enhance vagus nerve activity?
Diaphragmatic breathing
Nervine herbs such as passionflower, ashwagandha and chamomile
The gut-brain axis explained
Brain and gut develop from the same embryonic tissue and share nerve endings and chemical transmitters. Serotonin plays a role in peristalsis and secretion. 95% of it is produced in the GIT. Possible link between poor gut health and depression.
How can dysbiosis contribute to depression/anxiety?
Gut microflora play a role in tryptophan synthesis, which is a precursor to serotonin. Also poor gut health may be deficient in the co-factors needed for tryptophan and serotonin production.
What factors can compromise digestion?
JONES
Junk food, processed food, refined sugars (slows peristalsis)
Over-eating and snacking
Nutritional deficiencies (ie stomach acid - zinc/B6)
Excessive protein
Stress
Coffee
Chewing
Implications of poor digestion and absorption?
NUT
Nutrient deficiencies - reduced delivery to tissues
Undigested food
- fermentation > bloating/discomfort
- putrefaction > polyamines
- clogging the bowel (Jensen)
Toxaemia - incomplete transformation of food (Ama)
Outline the stages in B12 digestion/absorption
- B12 is bound to a protein in food
- Goes into the stomach - HCL and pepsin - split the protein and B12
- R-protein from saliva comes down and binds to B12
- Leaves stomach into duodenum - pancreatic proteases come in and split the R-protein and B12
- Intrinsic factor (from the stomach) binds to the B12 and is absorbed in the terminal ileum
How is vit D3 synthesised?
- Pro-vitamin D (precursor form in skin)
- UV light hits skin and converts pro-vit D to cholecalciferol
- Cholecalciferol is transported in the blood to the liver and kidneys which make D3 (calcitriol is the active form of vit D made by the kidneys).
Note: ‘chole’ - vit D requires cholesterol
And co-factor magnesium
Functions of vit D
BIC P
Bacterial species - plays a role in regulating them, and low D is associated with dysbiosis
Immune system - regulates - low levels linked to autoimmunity and allergies
Calcium - draws calcium from the digestive system and into blood
Phosphorus - also aids the intestinal absorption of phosphorus.
Note K2 - deposits the calcium onto bone. It triggers osteocalcin which is responsible for deposition of calcium onto bone. K2 is also produced by your microflora.
How is a healthy digestive system crucial for cellular health?
Delivering the required nutrients to all our cells. Eg, anti-oxidants to protect our cells from free radicals/oxidative damage. Supporting detoxification.
Poor detoxifying and eliminating - toxic burden on cells > disrupting cellular function > potential DNA damage > possible cancerous changes.
Why is the digestive system important for bone health?
Absorption of collagen and key minerals such as calcium, phosphorus, magnesium and potassium.
Absorption of the amino acids required to build collagen.
K2 in the microflora.
Why is the digestive system important for muscle health?
Muscles require nutrients to support their activity:
Calcium - muscle contraction
Magnesium - muscle relaxation
Iron - delivery of oxygen to muscles
Sodium and potassium - nerve stimulation
Amino acids - muscle growth and maintenance
Deficiency > aching, cramping, fatigue
Why is the digestive system important for heart health?
Iron absorption - stomach acid is important for this process (converts it into absorbable form). Vit C aids its absorption. Good iron absorption > good oxygen delivery.
Heart requires an abundance of minerals, esp calcium.
Give an example of how digestive health is key to the endocrine system?
Eg low serotonin may in turn lead to low levels of melatonin, which may result in poor sleep. Needs co-factors, magnesium, zinc, C, B6 (B6 is key - converting serotonin to melatonin)
Endocrine glands such as the thyroid requires hormones iodine, tyrosine, selenium and zinc.
Give an example of how digestive health is key to the nervous system?
Electrical activity requires sodium, potassium, calcium and chloride ions, which must be ingested and absorbed.
Vitamin B12 myelinates neurons. A lack of B12 > neurological symptoms.
