Microbiota of the GI Tract Flashcards

1
Q

What does anaerobic mean?

A

Living in the absence of air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does aerobic mean?

A

Living in the presence of air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is facultative anaerobic bacteria?

A

Can grow in the presence of oxygen AND absence of oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is an obligate anaerobe?

A

Cannot grow in the presence of oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the normal range of pH in the mouth?

A

6.5 - 7.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the normal range of pH in the stomach?

A

1.5 - 4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the normal range of pH in the duodenum?

A

7 - 8.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the normal range of pH in the distal ileum?

A

4 - 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the normal range of pH in the colon?

A

5.5 - 6.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where are facultative anaerobes found?

A

Stomach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where are obligate anaerobes found?

A

Colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the GIT microbiota do?

A
Metabolism of dietary components
Modification of host secretions
Defence against pathogens
Production of essential metabolites
Immune system development
Host signalling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What types of food do GIT microbes come from?

A

Fibre (fruit, vegetables, pulses, whole grains)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How much energy is absorbed in the stomach/small intestine?

A

> 70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How much energy is absorbed in the large intestine?

A

5-10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the benefits of fibre in the diet?

A

Improves faecal bulking, eases passes, slower transit time
Contains phytochemicals, anti-oxidants and vitamins
Bacterial fermentation

17
Q

What are the 3 main short chain fatty acids?

A

Butyrate
Propionate
Acetate

18
Q

What are the functions of butyrate?

A

Epithelial cell growth and regeneration

19
Q

What are the functions of propionate?

A

Gluconeogenesis in the liver

Satiety signalling

20
Q

What is the functions of acetate?

A

Transport in blood to peripheral tissues

Lipogenesis

21
Q

What is the barrier effect?

A

Microbiota prevents colonisation of pathogens

Inhibit overgrowth of pathogenic bacteria

22
Q

What does the outer mucus layer of the gut do?

A

Barrier effect

23
Q

What does the inner mucus layer of the gut do?

A

Prevents bacterial penetration

24
Q

What is the effect of dysbiosis of the gut microbiota composition?

A

DIsrupts homeostasis and can lead to gut inflammation

25
Q

What is GPR43/FFAR2 activated by and what is the result?

A

Activated by acetate, propionate, butyrate
Result: GLP-1 secretion
Inhibits fat accumulation

26
Q

What is GPR/FFAR3 activated by and what is the result?

A

Activated by propionate and butyrate
Result: PYY secretion
Improves insulin resistance and satiety signalling to brain

27
Q

What is GPR109A activated by and what is the result?

A

Activated by butyrate

Suppresses colonic inflammation and carcinogenesis

28
Q

What are the different factors that influence the microbiota through life?

A
Birth
Feeding
Weaning
Diet expansion
Diet contraction
DIet maintenance