The Microbiota of the Gut

Question 1

Do conditions in the GI tract become increasingly anaerobic or aerobic?

Answer 1

Anaerobic

Question 2

Where is most bacterial found in the GI tract?

Answer 2

In the colon

Question 3

Where is bacterial most variable in the GI tract?

Answer 3

Mouth

Question 4

What is the transit time of the mouth?

Answer 4

1 min

Question 5

What is the transit time of the oesophagus?

Answer 5

4-8 seconds

Question 6

What is the transit time of the stomach?

Answer 6

2-4 hrs

Question 7

What is the transit time of the small intestine ?

Answer 7

3-5 hr

Question 8

What is the transit time of the colon?

Answer 8

10hr-several days

Question 9

What is meant by anaerobic?

Answer 9

Living in the absence of air

Question 10

What is meant by facultative anaerobic bacteria ?

Answer 10

can grow in the presence of oxygen and in the absence of oxygen

Question 11

What is meant by obligate anaerobe?

Answer 11

Cannot grow in the presence of oxygen

Question 12

What is aerobic bacteria?

Answer 12

Living in the presence of air

Question 13

How does oxygen vary in the GI tract?

Answer 13

Different parts of the GI tract use different concentrations of oxygen

Question 14

What happens to materials that cannot be broken down and digested by the small intestine?

Answer 14

Will reach the large intestine to be broken down by bacterial fermentation

Question 15

Where is the site of most carbohydrate fermentation?

Answer 15

Ascending colon

Question 16

Where do alot of colonic diseases start?

Answer 16

In the distal colon

Question 17

Give an example of something that has to be broken own by bacterial fermentation?

Answer 17

Cellulose

Question 18

How does our gut defend against bad bacteria?

Answer 18

The muocous layer forms a barrier between the luminal bacterial population and the epithelial cells

Question 19

What are the 2 mucous layers surrounding the epithelium of cells?

Answer 19

Inner and outer mucous layer

Question 20

What does the inner layer of mucous stop?

Answer 20

The penetration of the pathogenic bacteria

Question 21

What happens to the few bacteria that do penetrate through the epithelium?

Answer 21

They are dealt with efficiently by the immune system

Question 22

What does a dysregulated immune response lead to?

Answer 22

Inflammation

Question 23

What is the largest lymphoid organ?

Answer 23

Gut

Question 24

What is commensal bacteria?

Answer 24

Commensal microflora is an integral part of a complex of natural mechanisms on mucosal surfaces and skin that safeguard the resistance of the organism against pathogenic micro-organisms.

Question 25

When does autoimmune diseases of the gut occur?

Answer 25

When the immune system can no longer distinguish between harmful detrimental pathogens and commensal bacteria

Question 26

What is dysbiosis?

Answer 26

Dysbiosis is a term for a microbial imbalance or maladaptation on or inside the body, such as an impaired microbiota.

Question 27

What type of bacteria predominantly live in the colon?

Answer 27

Anaerobic bacteria

Question 28

What do resident bacteria do?

Answer 28

Lower pH
Create a physical mucosal barrier
Produce active compounds that kill oncoming pathogens