Lecture 14- Microbiomes - commensals and pathogens

Question 1

define microbiome

Answer 1

community of symbiotic microorganisms associated with a particular host body site/tissue

Question 2

components of breastmilk which aid microbiome formation

Answer 2

IgA/lactoferrin, help prevent enterobacteria adhesion
lactobaccilus and other gut-associated anaerobes
bacteria helping to break down non-digestible parts of milk e.g. oligosaccharides

Question 3

immune defects in microbiome-free mice

Answer 3

lack of Th17 cells/IgA production

Question 4

potential mechanism of IBD development

Answer 4

defects in mucosal firewalls, allowing incorrect microbiome compositions to emerge- e.g. insufficient killing of symbionts

Question 5

mutation common in Chron’s

Answer 5

NOD2, which impairs bacterial killing and can lead to inflammation

Question 6

mechanism of post-abx cdiff infection

Answer 6

diminished bacterial diversity, leading to less secondary bile acid production and less controlled cdiff populations

Question 7

faecal transplant success rate for c. diff

Answer 7

50-95

Question 8

less ‘risky’ way of doing faecal transfer

Answer 8

taking own sample- autologous faecal transfer

Question 9

more ‘specific’ ways of treating issues w the microbiome

Answer 9

probiotics, postbiotics

Question 10

probiotics, postbiotics, prebiotics

Answer 10

probiotics- single strains or assemblages of bacteria
postbiotics- bioactive molecules produced by bacteria
prebiotics- material used to target microorganisms, e.g. non-digestible carbohydrates