small bowel and large intestine Flashcards
intestinal microbiome: recall the physiological and pathophysiological roles of the intestinal microbiome
net weight of microbiota
diverse, highly metabolically active: 1500g
type of relationship between microbiota and human
symbiotic
when do microbiota develop and decline
first years of life, decline in later life
why very few bacteria in stomach or proximal small intestine
harsh environments
most prevalent species of bacteria
bacteriodietes (gram -ve, anaerobic, non-spore)
6 physiological roles of microbiota
synthesise and excrete vitamin K (coagulation), prevent pathogen colonisation by competition, antagonise other bacteria which inhabit or kill non-indigenous bacteria, stimulate cross-reactive antibody production, stimulate development of some tissues (e.g. caecum), break down fibre, produce short chain fatty acids
function of production of short chain fatty acids
regulate gut hormone release, energy source drug metabolism, insulin sensitivity, bile acid metabolism, lipid metabolism,
what does gat bacteria population help maintain and prime
immunological system
effect of inappropriate population or loss of commensal bacteria
predisposition to infection and illness
what is a faecal transplant
re-instate bacteria (appendix may provide safety for bacteria) for persistant infection
what type of bacteria is “friendly” bacteria (prevent colonisation of potential pathogens)
bifidobacteria (gram +ve, non-spore, lactic acid)
what has gut bacteria been linked with
drug metabolism, insulin resistance, bile acid metabolism, lipid metabolism, obesity
