L6 - Preferences Shaping Microbiota Flashcards
Which article descrubed competition over different fructan utilisation abillity between bacteroides (showing diet affecting diversity)
Sonnenburg et al 2010
Which 2 components differ between bacteroides like theta ovstus and caccae which causes differences in fructan abbity
Htcs - hybrid 2 component system which is a sensor for different glycans
And also the types of glycanases encoded
Which GH is encoded by b theta which makes it the only one who can grow on fructan type levan
GH32 which hydrolyses b2-6 fructose polymera
Why can b theta not grow in inulin fructan presence
Inulin is a b2-1 fructan polymer. Doesnt have the enzymes for that
Which PL is present in caccae and ovatys which allows them to frow in b2-1 inulin polymer
PL 19 (hyrolyses b2-1)
Pre weaning/ solid food , what colonises the infant gut which is another rxample of glycan preference
Bacteroides and bifido infantis
Why do these colonise in infants
Both able to ise hmo from breast
How can bacteroides like bt use hmo
Via their mucus utlisation systems
Which specific hmo allows only bifido infantis to colonise
Lacto-n- neotetraose (Lnnt)
Bifido cant use mucus
When low fibre diets are continued over a long time what happens
Extinction of previously colonised bacteria due to preferences within spexies and outside of phyla
Which populations are of risk of ibd and others like colorectal cancer
Westernised due to low fibres
What did murphy et al find 2012 about increased fibre
Reduced risk of colorectal cancer by 11% from fruit and veg glycans. (Possibly due to butyrate?)
3 main important points of dietary fibre
1- scfa
2- protect mcuosal barrier (desai 2017)
3- improve diversity (sonnenburg et al 2010)
What did sha 2013 find about importance of bifido presence
Reduced UC incidences via carbohydrate utilisation and low levels linked with ibd
Which lther species was low in ibd patients
Prevotella bacteroidetes (sha 2013)
