Diarrhoea Disease 1 Flashcards
what features prevent bacteria in the upper gut?
- Gastric acid
- Bile acids
- Propulsive motility
- Pancreatic enzymes
what are the roles of gut bacteria?
Ferment carbohydrate Produce short chain fatty acids Reduce colonic pH Inhibit pathogens Produce a range of vitamins Metabolise polyphenols Produce toxins and carcinogens
define fermentation
Anaerobic metabolism of carbohydrate and protein in human colon by the microbiota
what are the main fermented carbohydrates in human diet?
- Resistant starch
- Non starch polysaccharides (Wheat bran, oat fibre, other cereals, pectins, glucans)
- Sugar alcohols
- Non absorbed oligosaccharides and sugars
list examples of short chain fatty acids
Acetic, propionic, butyric, lactic acid & branched chain fatty acids
what are short chain fatty acids the product of?
fermentation of carbohydrate and protein
what is the function if SCFAs?
- Promote colonic absorption – reduce diarrhoea
- Provide energy, influence hormone release affecting satiety - Obesity
- Protect gut mucosa- IBD and cancer
- Influence lipid metabolism in different ways
what is the main SCFA to reach systemic blood?
Acetate
what is the role of acetic acid?
Used for energy
what are the roles of Propionate?
- Inhibits cholesterol synthesis.
- Inhibits lipid synthesis
- Increases insulin sensitivity
- Influences satiety hormones via g protein coupled receptors
which SCFA is the preferred fuel for colonic cells?
Butyrate
what is the role of butyric acid?
- Promotes healthy colonic mucosa
* Heals damaged mucosa
how does the pH in the proximal colon compare to the distal colon?
in proximal colon can be
define probiotics
Live microorganisms which when administered in adequate amounts confer a health benefit on the host.
define prebiotics
Carbohydrates or other compounds which selectively stimulate the growth of specific bacteria and promote health
