Integration 4: Gut Microbiome Flashcards
Humans are -
holobionts
* human selves and microbial selves
What is evidence of our co-evolution with the gut microbiome?
oligosaccahrides in human milk
* no nutritional value to babies but support growth of gut microbiome and thus immunity
What are common functions of the gut microbiome?
- immune system development
- gut function
- exclusion of pathogens
- gut tissue development
- nutrient acquisition
- host metabolism
What is our relationship with the gut microbiome?
symbiotic
dysbiosis
An alteration or modification in the gut microbiome that is linked to disease or metabolic disturbances
dysbiosis
An alteration or modification in the gut microbiome that is linked to disease or metabolic disturbances
What are related diseases of dysbiosis?
- obesity
- chronic inflammation
- diabetes
- colon cancer
- allergies
- heart disease
- autoimmune disease
- mental disorders
What has changed the gut microbiome?
industrialization
* decreased diversity
What are the potential mechanisms driving the disappearing microbiome?
- diet
- sanitation
- antibiotics
- C-sections and formulas
What is the fibre gap?
population wide lack of fibre intake
* reccomended: ~25-38 g/day
* current intake: ~12-19 g/day
* ancestral diet: > 100 g/day
What are the main SCFAs produced by microbes?
- acetate
- propionate
- butyrate
Functions of SCFAs
- fuel for epithelial cells
- reduce inflammation
- improve barrier function
- increase satiety
- improve insulin sensitivity
What separates the gut microbiome from us?
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.
What do the microbes eat if fibre intake is low?
the mucous layer!!!
What do emulsifiers do?
disrupt the gut barrier function promoting metabolic disorders and low-grade inflammation
What happens to the gut microbiome with excess protein intake?
increased BCFAs and ammonia and decreased butyrate
* decreased abundance of beneficial microbes, more inflammatory and may decrease mucous layer
What happens to tryptophan in the gut microbiota?
gets converted to bioactive metabolites
* indole derivaties: ligands for aryl-hydrocarbon receptors critical for immune responce
* 5-hydroxytryptophan: neurotransmitter involved in gut-brain axis
how does increased consumption of dietary fat alter the gut microbiome?
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
How does PUFA alter the gut microbiome?
- increases abundance of good microbes
- promotes SCFA production
- maintains barrier
- increases diversity
- mediates anti-inflammatory effects
What has had the biggest impact in changing our gut microbiome?
change in diet
What are nutritional support strategies to modulate the gut microbiome?
- microbiota accessible carbohydrates
- fermentable fibres
- prebiotics
How can health promoting microbes be introduced?
- probiotics (general)
- live biotherapeutics (disease state targeted)
What is the challenge with strategies to improve gut microbiota?
We are all different
* microbes differ between people
What is personalized nutrition?
Send in poop sample to company who analyze it and tell you what foods to eat
