Physiology of probiotics

Question 1

What is mutualistic interaction?

Answer 1

Both organisms benefit

Question 2

What is commensal interaction?

Answer 2

No contribution between host and microbe

Question 3

What is pathogenic interaction?

Answer 3

The microbe is harmful to the host

Question 4

Which factors produced by LAB inhibit microbes?

Answer 4

Low pH will be energy draining
H202 oxidative stress
Bacteriocins have antimicrobial effect
Nutrient depletion prevents growth

Question 5

Which factors affect microbiome?

Answer 5

Lifestyle, diet, antibiotics, hygiene

Question 6

What can the microbiome affect?

Answer 6

Hyperimmunity, immunodeficiency, inflammation, metabolic dysfunction

Question 7

Where in the body is the most bacteria found?

Answer 7

Colon
10^12 cells/g DW

Question 8

What are the main phyla in the colon?

Answer 8

Firmicutes and bacteriodetes

Question 9

Which neuroactive molecules are produced/affected by bacteria?

Answer 9

Oxytoxin
GABA
BDNF
4-EPS decreases
SCFA

Question 10

Can probiotics have a positive influence on the immune system?

Answer 10

Yes

Question 11

What is the gut-brain axis and is it affected by the microbiome?

Answer 11

Bidirectional communication between gut and brain. Yes it is.

Question 12

Can using probiotics restore imbalances? q

Answer 12

Yes

Question 13

How does the gut microbiome communicate with the brain?

Answer 13

Signal substances

Question 14

What is OGIT?

Answer 14

Oral gastro intestinal tract model

Question 15

What is OGIT used for?

Answer 15

Determine the effect of saliva, acid+pepsin, bile on the survivability and stress mechanisms and probiotic functionality

Question 16

How can probiotics help to keep pathogens out?

Answer 16

They compete for attachment sites. If a probiotic is already attached there is no space for a pathogen

Question 17

What is a classical cell count method?

Answer 17

Viable count

Question 18

What is a modern cell count method?

Answer 18

Flow cytometry

Question 19

Why is viable count not great for probiotics?

Answer 19

Growth on plates is no good representative of growth in the body

Question 20

Dormancy may be common among probiotic species, how does that make viable count an unsuitable method?

Answer 20

Because dormant cells would not grow on a plate

Question 21

Does flow cytometry give a better representation of the status of the cell?

Answer 21

Yes