7.7 Non-digetsible Food Components Flashcards
What are the components of the large intestine
cecum, colon, rectum and anus
What are the different sections of the colon
the ascending colon, transverse colon, descending colon and sigmoid colon
What is the main fermentation chamber in the large intestine
The ascending colon due to its high bacteria population
What are some functions of the large intestine
-colonic bacterial metabolic activity, fermenting carbohydrates to produce short chain fatty acids
-vitamin K absorption
-absorption of water and electrolytes from colonic contents to form solid faeces
-storage of faecal matter
-prevention of establishment of pathogenic bacteria
Describe the different sub categories of dietary fibre
Dietary fibre can be soluble or insoluble.
Soluble fibres can form viscous solutions or they can be fermented by bacteria to produce short chain fatty acids
What is the benefit of fermentable fibre
The soluble fibre can be fermented by bacteria to produce metabolites such as short chain fatty acids. Different SCFAs have different health benefits such as acting as energy sources, reducing cholesterol synthesis, stimulating gut cell proliferation and synthesising glucose. These acids also reduce the pH of the colon.
What are some short chain fatty acids
Acetic acid, propionic acid, butyric acid
What is the effect of fibre on gut transit time
In the stomach, soluble fibre reduces gastric emptying.
In the colon, insoluble fibre increases propulsion via peristalsis
Describe the effects of dietary fibre on digestion and absorption
Soluble viscous fibre reduces luminal mixing, reduces interactions between enzymes and substrates, reduces interactions between receptors and stimuli and reduces the absorption of nutrients. This reduces digestion and absorption and lowers the glycaemic response
What are some advantages of a high fibre diet
-slower absorption of nutrients so increased satiety
-lower plasma cholesterol
-increased GI transit and stool output
-SCFA in colon lowering colonic pH
