Microbiota 2

Question 1

2 effects microbiota have on mucous layer?

Answer 1

direct: block binding sites
indirect: interact with pattern recognition receptors on enterocytes

Question 2

microbiota interact with pattern recognition receptors on enterocytes to do what?

Answer 2

down-regulate

develop tolerance for TLR2, 4

Question 3

PAMPS from microbiota stim 4 main things on mucous/gut epithelium

Answer 3

stims mucin production
prolif of crypt/Paneth cells
stims antimicrobial peptides
induce regulatory cytokines

Question 4

SCFAs inhibit what in mucous/gut epithelium?

Answer 4

inflamm cytokines

Question 5

IL-22 after PAMP interaction does what?

Answer 5

promotes epithelial barrier integrity

Question 6

When do Peyer’s patches vs. mesenteric lymph nodes develop?

Answer 6

Peyer’s patches : prenatally

mesenteric lymph nodes: post natally

Question 7

what happens to Peyers patches after vaginal birth?

Answer 7

enlarges

Question 8

how do you get IgA production in gut?

Answer 8

from B-cells induced by microbiota

Question 9

do germ free mice have MAIT cells?

Answer 9

nope

Question 10

lymphocyte subset development’s end goal is to do what?

Answer 10

so it can respond differently to normal microbiota and pathogens

Question 11

normal microbiota causes what kind of inflamm?

Answer 11

physiological inflamm without damage

Question 12

pathogens induce what kind of inflamm

Answer 12

damaging pathological inflamm

Question 13

How does epithelium PRR detect invasion?

Answer 13

TLR5 at basolateral surface

Question 14

how do epithelium PRR detect friend from foe?

Answer 14

‘senses’ commensals at luminal edge rather than pathogens at the epithelial surface

Question 15

what does it mean if you have inflammasome signalling and weak TLR binding?

Answer 15

could be a pathogen trying to get in!

Question 16

what id dysbiosis?

Answer 16

altered normal microbiota

Question 17

what is involved with kwashiokor?

Answer 17

gut microbiota

Question 18

what was the Malawian twin kwashiokor study results telling us?

Answer 18

the one with kwashiokor couldn’t recover the gut microbiota even after therapeutic diet

Question 19

what happened to mice fed kwashiorkor diet?

Answer 19

lost weight, microbiome changed couldn’t recover even most therapeutic diet

Question 20

why couldn’t the microbiome recover post kwashiorkor? and cause undernutrition?

Answer 20

kwashiorkor microbiota made chemicals that selectively inhibited TCA cycle enzymes affecting energy metabolism

Question 21

obese people’s microbiome are what?

Answer 21

less diverse

Question 22

DMII people have what kind of microbiome?

Answer 22

altered, less diverse

Question 23

less diverse microbiome = ?

Answer 23

higher levels of insulin resistance
serum triglycerides
cholesterol

Question 24

if you transfer obesity microbiome between animals what happens?

Answer 24

the lean animal become obese!!

Question 25

lean subjects have more what with obesity associated inflammation?

Answer 25

T-regs

Question 26

what is increased in inflammation in obese mice?

Answer 26

Bifidobacteria

Question 27

obesity changes 3 things in gut microbiota

Answer 27

altered composition altered fermentation increased energy harvest

Question 28

inflammatory bowel disease and microflora, describe

Answer 28

elevated immune responses decreased diversity increased intestinal permeability

Question 29

diet, antibiotic and appendectomy does what to microbiota?

Answer 29

reduces diversity

Question 30

how are microbiota involved with allergies?

Answer 30

seems to be less diversity in infants leads to more allergies

Question 31

intestinal microbiota and infectious disease are related how? 3 ways

Answer 31

spread of resistance genes infections at extra-intestinal sites gut infections

Question 32

microbiota that escape GIT cause?

Answer 32

UTIs, resp, wound infections | usually need abnormal host

Question 33

C.Diff can cause what?

Answer 33

pseudomembranous colitis

Question 34

microbiota if altered could render you more susceptible to what bug?

Answer 34

salmonella or other pathogens | overgrowth of other commensals

Question 35

C.Diff stats:

Answer 35

gram +ve anerobic spore forming rod

Question 36

when does C.Diff happen?

Answer 36

overgrows when gut microbiota altered via drugs etc.

Question 37

what does C.Diff do to you?

Answer 37

adheres to mucosal epithelium, produces toxins | inflamm/bowel necrosis

Question 38

C.Diff big problem where?

Answer 38

in hospitals: hypervirulent, resistant strains

Question 39

how to treat C.Diff ?

Answer 39

more antibiotics! | Metronidozole +- vancomycin

Question 40

who has 4x greater risk of recurrent C.Diff infection?

Answer 40

appendectomy

Question 41

how do the microbiota of people with recurrent C.diff look?

Answer 41

reduced diversity | hardly any bacteroides

Question 42

how to treat C. Diff pseudomembranous colitis?

Answer 42

bacteriotherapy i.e.. fecal transplant

Question 43

success rate of bacteriotherapy?

Answer 43

91-98% success rate

Question 44

Pre and Probiotics beneficial?

Answer 44

jury's still out on that one. | may help with recovery from darrhoeas/rotavirus

Question 45

2 forms of experimental systems to test microbiota interventions?

Answer 45

twins studies | germ free mice