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Flashcards in Microbiota 2 Deck (45):
1

2 effects microbiota have on mucous layer?

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

2

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

down-regulate
develop tolerance for TLR2, 4

3

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

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

4

SCFAs inhibit what in mucous/gut epithelium?

inflamm cytokines

5

IL-22 after PAMP interaction does what?

promotes epithelial barrier integrity

6

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

Peyer's patches : prenatally
mesenteric lymph nodes: post natally

7

what happens to Peyers patches after vaginal birth?

enlarges

8

how do you get IgA production in gut?

from B-cells induced by microbiota

9

do germ free mice have MAIT cells?

nope

10

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

so it can respond differently to normal microbiota and pathogens

11

normal microbiota causes what kind of inflamm?

physiological inflamm without damage

12

pathogens induce what kind of inflamm

damaging pathological inflamm

13

How does epithelium PRR detect invasion?

TLR5 at basolateral surface

14

how do epithelium PRR detect friend from foe?

'senses' commensals at luminal edge rather than pathogens at the epithelial surface

15

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

could be a pathogen trying to get in!

16

what id dysbiosis?

altered normal microbiota

17

what is involved with kwashiokor?

gut microbiota

18

what was the Malawian twin kwashiokor study results telling us?

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

19

what happened to mice fed kwashiorkor diet?

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

20

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

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

21

obese people's microbiome are what?

less diverse

22

DMII people have what kind of microbiome?

altered, less diverse

23

less diverse microbiome = ?

higher levels of insulin resistance
serum triglycerides
cholesterol

24

if you transfer obesity microbiome between animals what happens?

the lean animal become obese!!

25

lean subjects have more what with obesity associated inflammation?

T-regs

26

what is increased in inflammation in obese mice?

Bifidobacteria

27

obesity changes 3 things in gut microbiota

altered composition
altered fermentation
increased energy harvest

28

inflammatory bowel disease and microflora, describe

elevated immune responses
decreased diversity
increased intestinal permeability

29

diet, antibiotic and appendectomy does what to microbiota?

reduces diversity

30

how are microbiota involved with allergies?

seems to be less diversity in infants leads to more allergies

31

intestinal microbiota and infectious disease are related how? 3 ways

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

32

microbiota that escape GIT cause?

UTIs, resp, wound infections
usually need abnormal host

33

C.Diff can cause what?

pseudomembranous colitis

34

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

salmonella or other pathogens
overgrowth of other commensals

35

C.Diff stats:

gram +ve
anerobic
spore forming
rod

36

when does C.Diff happen?

overgrows when gut microbiota altered via drugs etc.

37

what does C.Diff do to you?

adheres to mucosal epithelium, produces toxins
inflamm/bowel necrosis

38

C.Diff big problem where?

in hospitals: hypervirulent, resistant strains

39

how to treat C.Diff ?

more antibiotics!
Metronidozole +- vancomycin

40

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

appendectomy

41

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

reduced diversity
hardly any bacteroides

42

how to treat C. Diff pseudomembranous colitis?

bacteriotherapy i.e.. fecal transplant

43

success rate of bacteriotherapy?

91-98% success rate

44

Pre and Probiotics beneficial?

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

45

2 forms of experimental systems to test microbiota interventions?

twins studies
germ free mice