microbiome

Question 1

what does the gut microbiome regulate

Answer 1

1. immune system
2. nutrient absoprtion
3. energy homeostasis
4. protection against paathogens

Question 2

function of gut microbiome for human health

Answer 2

1) provides nutrients + metabolites that we dont have the genes to make
(vitamins)
2) helps ferment/ break down food to extract nutrients
- break down lactose
3) comunicate with immune system
4) produce anti-inflammatory compounds that fight off other diseases causing microbes

Question 3

what things affect gut microbiome make up

Answer 3

1. diet
2. exercise
3. medications

Question 4

what is metagenomics

Answer 4

study of genetic material recovered directly from biological samples, study of microbial communities

Question 5

changes in microbiome suggest what?

Answer 5

changes in microbiome correlate with different disease states
- means that we can manipulate bacterial communities to treat disease

Question 6

how is the microbiome specific + what can it tell us about the person

Answer 6

specific to

1) population
2) geographical orgiinal
3) environmental exposure
4) diet= what you eat
5) age
6) who you live with
7) where you live
8) smoke
9) mediation
10) who you kiss
11) pets

Question 7

what does twin studies of microbiome suggest?

Answer 7

twins who live in different environments have very different gut microbiome makeup
- suggests that microbiome is NOT inherited

Question 8

what does it mean when the microbiome is ‘acquired’

Answer 8

means there is no genetic heritability of the microbiome, it depends on :
environment , geogrpahy, who you live with, where you live, diet, age, smoke, medications, who you kiss, pets

Question 9

hwo does obesity + T2diabetes related to gut microbiome?

Answer 9

• genetic changes responsible for 10-20% cause of obestiy + T2D
• environmental factors change microbiome can also explain these metabolic diseases

Question 10

explain the mice example in terms of obesity + microbiome

Answer 10

germ free mice are leaner than mice with normal microbiota beacuse:
- microbiome is able to EXTRACT energy from food

1) transfer gut microbiome of lean mice into a germ free mice = no effect (mice stays lean)
2) transfer gut microbiome of ob/obese mice into germ free mice = microbiome ^ energy extraction from food = ^ glycoside hydrolases = ^ body fat by 40%

Question 11

obesity changes to gut microbiome?

how can microbiome be used to predict obesity?

Answer 11

1) animal models of obesity show
increased Firmicutes
decreased Bacteroids in
Firmicutes: Bacteroids ratio

2) surgical induced weight loss OR diet induced weight loss = reversed changes in Firmicutes:Bacteroids ratio

3) 33-65% ability to predict indivdual obesity status by looking at microbiome
- still a weak assocaition bw obesity + gut microbiome bc:
1- large interpersonal variation
2- small sample size

Question 12

what is the result of increased ability to extract energy from food ?

Answer 12

microbiome produces low-level inflammation

Question 13

effects of dietary fibre on gut microbiome?

Answer 13

enzymes in gut microbiome break down dietary fibre –> release SCFA –> low pH

low pH = limits growth of some harmful bacteria (Clostridium difficle) –>
can
1) stimualte immune cell activity
2) maintian normal BGL + cholestrol