Gut Flora Flashcards
Why does the upper gut have low gut flora populations?
Gastric acidity
Propulsive motility
Pancreatic enzymes
What factors of the large intestine allow a large and complex ecosystem of gut flora to develop?
Stagnant motility with retropulsive contractions
pH buffered by bicarbonate ions
How many different species of bacteria exist in the large intestine?
Over 400
What is the importance of gut flora?
They have roles in nutrient metabolism, xenobiotic and drug metabolism, antimicrobial protection and immunomodulatiom
Gut bacteria are mostly strict anaerobes. T/F?
True
Approximately what mass of undigested carbohydrate is fermented by gut bacteria every day?
60g
Bacteria in the large intestine can ferment carbohydrates to produce short chain fatty acids including acetic acid, propionic acid and butyric acid. Why are these useful?
Acetic acid is a substrate for fat synthesis in the liver
Propionic acid is used as an energy source for the liver, is gluconeogenic and may reduce cholesterol synthesis
Butyric acid is a major energy source for colonic cells and can stimulate differentiation of colonic cells and can massively stimulate sodium and chloride ion absorption