the gut microbiome

Question 1

the gut is

Answer 1

the most heavily colonised organ in the body

Question 2

surface area of GI tract

Answer 2

surface area of a tennis court- 200m^2

Question 3

where more than…. of all microbes in the body are found

Answer 3

70%

Question 4

are there more strict anaerobes or facultative aerobes and aerobes

Answer 4

more strict anaerobes

Question 5

which two phyla dominate the gut

Answer 5

• bacteroidetes

- firmicutes

Question 6

how many bacterial species

Answer 6

500-1000

Question 7

where the most bacterial species

Answer 7

the colon

Question 8

colonisation begins

Answer 8

at brith during passage through the birth canal

–>Intestinal microbiota of infants shows similarities with the vaginal microbiota of their mothers. Infants delivered through caesarean have diff gut microbiota composition compared to vaginal delivered babies.

Question 9

what effects gut microbiome

Answer 9

genetics and diet

Question 10

what collectively make up inflammatory bowel disease

Answer 10

crowns disease (CD) and ulcerative colitis (UC)

Question 11

HMP and IBD

Answer 11

investigating links between microbipme, host and IBD

Question 12

nod2 and CD

Answer 12

3 polymorphisms in nod2 associated with CD- each polymorphism results in reduced activation of NF-kB in response to bacterial peptidoglycan

Question 13

Nod2

Answer 13

intracellular sensor for bacterial peptidoglycan

Question 14

Nod2 function is required

Answer 14

for optimal defence in expression very important antimicrobial peptide- critics component of the innate immune system

Question 15

obesity and gut microbial ecology

Answer 15

associated with a large shift in the relative abundance of the taxa present- 50% reduction in bacterodeites and a significant increase in firmicutes
–> in mice and human

Question 16

an ‘obese microbiome’

Answer 16

promotes weight gain when transplanted to a germ-free mouse, compared to a comparable transplantation of a lean micro biome

Question 17

nod2 is required for

Answer 17

optimal defensin expression

Question 18

defensins

Answer 18

are very important antimicrobial peptides- critical components of the innate immune systems

Question 19

IBD5

Answer 19

helps maintain the integrity of the epithelial barrier- association between IBD5 polymorphisms and both UC and CD

Question 20

IL-23R

Answer 20

susceptible gene for both UC and C. receptor for IL-23R, plays a role in activation and perpetuation of inflammatory response

Question 21

ATG16L1

Answer 21

polymorphisms restricted to CD and not UC

-gene is part of the autophagosome pathway which has been implicated in handling intracellular bacteria

Question 22

high levels of adhesive and invasive …. have been reported in CD patients

Answer 22

E.coli

Question 23

intracellular invasion by AIEC is associated with

Answer 23

active CD and intestinal pathology

Question 24

many studies have reported an abundance of…. in IBD patients

Answer 24

Enterobacteriacaea

Question 25

a decrease in Faecalibacterium prausnitzii

Answer 25

has been associated with a UC and highly indicative CD

Question 26

faecalibacterium prausnitzii

Answer 26

s an anti-inflammatory commensal bacterium identified by gut microbiota analysis of Crohn disease patients–> secreted metabolites from the bacterium promoted production of anti-inflammatory cytokines, whilst inhabiting production of pro-inflammatory cytokines.

Question 27

anti-inflammatory gut organisms such as faecalibacterium

Answer 27

might be an effective probiotic for treatmentment of CD

Question 28

when thinking about eradicating certain microbiota like H.pylori (which may cause gastric carcinomas)..

Answer 28

must weigh up potential for unintended implications- microbes have co-evolved with humans and eradication of one or more species may upset the delicate balance that has evolved over the millennia

Question 29

rDNA from faecal samples of healthy and CD individuals was applied to a microarray

Answer 29

revealing many shifts in microbiota

Question 30

microarray tools for investigating dysbiosis

Answer 30

study used intro from gut micro biome to design custom phylogenetic microarray- composed of rRNA probes representing around 500 bacterial species from the human and animal gut

Question 31

NOD 2

Answer 31

NOD2 plays an important role in the immune system. It recognizes bacterial molecules (peptidoglycans) and stimulates an immune reaction.

NOD2 is an intracellular pattern recognition receptor, which is similar in structure to resistant proteins of plants and recognizes molecules containing the specific structure called muramyl dipeptide (MDP) that is found in certain bacteria.