Integration 4: Gut Microbiome

Question 1

Humans are -

Answer 1

holobionts
* human selves and microbial selves

Question 2

What is evidence of our co-evolution with the gut microbiome?

Answer 2

oligosaccahrides in human milk
* no nutritional value to babies but support growth of gut microbiome and thus immunity

Question 3

What are common functions of the gut microbiome?

Answer 3

• immune system development
• gut function
• exclusion of pathogens
• gut tissue development
• nutrient acquisition
• host metabolism

Question 4

What is our relationship with the gut microbiome?

Answer 4

symbiotic

Question 5

dysbiosis

Answer 5

An alteration or modification in the gut microbiome that is linked to disease or metabolic disturbances

Question 5

dysbiosis

Answer 5

An alteration or modification in the gut microbiome that is linked to disease or metabolic disturbances

Question 6

What are related diseases of dysbiosis?

Answer 6

• obesity
• chronic inflammation
• diabetes
• colon cancer
• allergies
• heart disease
• autoimmune disease
• mental disorders

Question 7

What has changed the gut microbiome?

Answer 7

industrialization
* decreased diversity

Question 8

What are the potential mechanisms driving the disappearing microbiome?

Answer 8

• diet
• sanitation
• antibiotics
• C-sections and formulas

Question 9

What is the fibre gap?

Answer 9

population wide lack of fibre intake
* reccomended: ~25-38 g/day
* current intake: ~12-19 g/day
* ancestral diet: > 100 g/day

Question 10

What are the main SCFAs produced by microbes?

Answer 10

• acetate
• propionate
• butyrate

Question 11

Functions of SCFAs

Answer 11

• fuel for epithelial cells
• reduce inflammation
• improve barrier function
• increase satiety
• improve insulin sensitivity

Question 12

What separates the gut microbiome from us?

Answer 12

mucous layer
Sterile, doesnt really have microbes associated with it. Protects intestinal cells and immune system from the microbes. They provide benefits but if in direct contact with immune system we would die (sepsis) so keeps these microbes away from us to avoid the activation of our immune system.

Question 13

What do the microbes eat if fibre intake is low?

Answer 13

the mucous layer!!!

Question 14

What do emulsifiers do?

Answer 14

disrupt the gut barrier function promoting metabolic disorders and low-grade inflammation

Question 15

What happens to the gut microbiome with excess protein intake?

Answer 15

increased BCFAs and ammonia and decreased butyrate
* decreased abundance of beneficial microbes, more inflammatory and may decrease mucous layer

Question 16

What happens to tryptophan in the gut microbiota?

Answer 16

gets converted to bioactive metabolites
* indole derivaties: ligands for aryl-hydrocarbon receptors critical for immune responce
* 5-hydroxytryptophan: neurotransmitter involved in gut-brain axis

Question 17

how does increased consumption of dietary fat alter the gut microbiome?

Answer 17

promotes the growth of bile-tolerant microbes converting primary to secondary which can be carcinogenic
* increases mucous permeability
* increased risk of colon cancer and IBS

Question 18

How does PUFA alter the gut microbiome?

Answer 18

• increases abundance of good microbes
• promotes SCFA production
• maintains barrier
• increases diversity
• mediates anti-inflammatory effects

Question 19

What has had the biggest impact in changing our gut microbiome?

Answer 19

change in diet

Question 20

What are nutritional support strategies to modulate the gut microbiome?

Answer 20

• microbiota accessible carbohydrates
• fermentable fibres
• prebiotics

Question 21

How can health promoting microbes be introduced?

Answer 21

• probiotics (general)
• live biotherapeutics (disease state targeted)

Question 22

What is the challenge with strategies to improve gut microbiota?

Answer 22

We are all different
* microbes differ between people

Question 23

What is personalized nutrition?

Answer 23

Send in poop sample to company who analyze it and tell you what foods to eat