End Of L3 And L4

Question 1

What is the dysbiosis seen in lung disorders

Answer 1

Asthma,copd and cf all have over powering levels of proteobacteria

Question 2

How does scfa have to do with gut lung acis

Answer 2

Dampens downt he chances of chronic inflammation

Question 3

What did huffnagle 2014 find on reducing allergies in lungs cia dietary fibre

Answer 3

Increased dietary fibre increased scfa which induced haemotapoesis of dc which arent able to predent and activate th2 responses

Question 4

Who did an article on linking correlation yo causation via microbiome

Answer 4

Zhao 2013

Question 5

What did zhao 2013 find

Answer 5

Using longitudinal or cross sextional studies and multisite sampling of gut microbiota for composition and functional analysis

Identify key microbiota via stats tools like principle component analysis

Isolate in culture or interventions to see if leceos of the microbiota impact on phenotypes

Identify if these attected metabolic,proteomic and transcriptomic patterns for cause

Question 6

What type of microbiota seen in gut

Answer 6

Mostly bacterial

Question 7

Why is there most in colon 10^11

Answer 7

Slower digestion and not acidic

Question 8

How are bacteria for our health

Answer 8

The 5 main aspects highlighted in janeways

Question 9

What happens if dysbiotic

Answer 9

They can cause diseases like ibd and chronic diseases

Question 10

What are the largest phyla in gut

Answer 10

Bacteroidetes -ve and firmicutes +ve

Question 11

Which types of bacteroidetes usually

Answer 11

Bacteroides

Question 12

Why do we have larger metabolic potential with microbiota

Answer 12

They have 50-150 x more unique genes includint enzymatic genes for eg carb utilisatiom (GH, PL)

Question 13

What is the firsr example where microbiota signal to host for a mutualist relationship

Answer 13

Bacteroides theta signals host whwn it needs fucose as a carbon htilisation (hooper et al 1999)

Question 14

Explain hooper et al 1999 hypothesis

Answer 14

Bt uses a fucR repressor which binds to the fuc operon promoter which has enzyme genes for fucose metabolism eg L- fucose isomerase

When fucose is high, fucose can bind the fucR which removes it from operon. Sending signals for fucose metabolism

Another site was found called csp promoter. When this is expressed it sends signalling to host for more fucose.

In high fucose the fucR will bind and repress this so no signal to jost. When L - fucose is low can no longer suppress csp because L fucose is needed as a co repressor at this site with fucR. Therefore a aignal is sent to host for more fucose

Question 15

Which enzyme does b theta have for fucose removal on terminal sugars for carbon source

Answer 15

A fucosidase

Question 16

Example 2- scfa reudcing inflammation (smith et al 2013)

Answer 16

Scfa like butyrate and proprionate found to induce t regs by binding to the GPR43 on their surface.

This induced il 10 releasing foxp3 t regs.
Propionate increased proliferation of t regs by blocking hdac 6 and 9 which down regulate t regs

Found to reduce colitis symptoms

Question 17

3rd example - distinguishing friend from foe (round et al 2011)

Answer 17

Bacteroides fragilis bind tlr 2 via polysaccharide A. This instead of inducing th17 upregulates t regs releasing il10. Also allows balance of th2 and th1 responses.
Also reduced il17 levels and t regs suppression of th17

Question 18

Sxplain psa

Answer 18

Zwitteronic polysaccharide whoch is not seen on mant spexies, therefore producing a unique tlr2 response

Question 19

How do t regs suppress th17 responses

Answer 19

Trduce production of il 6 needed for th17 differentiation (zhang 2007)