Closing lecture basic challenge 1 Flashcards
1
Q
what does the GI microbiota consist of?
A
- bacteria(30-40 species make up 90% total population)
- archea (3 so far)
- viruses (10-100 species, bacteriophages)
- fungi/yeast ( 10-100 species)
- parasite eggs (NO)
2
Q
What is the difference in layers of the small and large intestines?
A
small intestine: has 1 single loose mucus layer, 1 glycocalyx layer and 1 cell layer
large intestine: has 1 loose outer mucus layer, 1 dense inner mucus layer, 1 glycocalyx layer and 1 cell layer
3
Q
What types of bacteria are there in the GI tracts?
A
- bacteroidota (gram negative and anaerobic)
- firmicutes/bacillota (gram positive and anaerobic)
- proteobacteria/pseudomonodota ( gram negative and mostly anaerobic)
- actinobacteria/actinomycetota (gram positive)
5 verrucomicrobia (only 1 species present in the GI tract)
4
Q
How are secondary bile acids made?
A
- primary bile acids are made and secreted.
- this will be deconjugated by bacteria
- this result in preliminary bile acid
- then other bacteria will perform dehydroxylation/ epimerisation
- this results in secondary bile acid
5
Q
What are the opposing effects of secondary BA’s?
A
- prevents overgrowth of C. Difficile
- increases colonic inflammatn and cancer risks
6
Q
What happens when fiber is added in the gut?
A
- microbiota metabolites it into fatty acids (acetate, butyrate and propionate)
- this interacts with GPR43 on the Treg cell
- this results in release of IL-10
- IL-10 inhibits effector T-cells
7
Q
In summary, what is the function of the gut microbiota in aspect of protection?
A
- competition for nutrients and attachement sites
- enhanced mucus and defensin production through host
- bacteriocins
- lowering pH by fermentation products (SCFA’s)
8
Q
What are aspects that are still unknown and potential adverse events?
A
- exclusion criteria:MDR bacteria, obesity, depression
- donor selection
- side effects
- administration frequency and route
