Integration Flashcards
(84 cards)
What is the gut microbiome
- microbes and what they can do
Types of gut microbes
- bacteria, fungi, protozoa, archaea, viruses
6 essential gut microbe functions
- nutrient acquisition
- immune regulation
- protection from pathogens
- metabolic signaling
- gut motility and development
- host metabolism
3 layers of gut
- microbes (most densely populated)
- mucus layer (sterile)
- intestinal cells
Nutrient acquisition
what we eat and do not digest or absorb in the small intestine becomes available for gut microbiome
Microbiomes of herbivores vs carnivores
herbivores: long and wide large intestine, fermentation chambers, houses more microbes
- carnivores: no large intestine, small intestine has all the enzymes needed to digest food completely
Short chain fatty acids produced from fiber fermentation
- acetate
- propionate
- butyrate
SCFAs function
signaling molecules
- substrates for microbes
- fuel for epithelial cells
- improve barrier function
- reduce inflammation
- increase satiety
- improve insulin sensitivity
We have a _____ relationship with out gut microbiome
- symbiotic
Diseases from gut dysbiosis
- obesity
- chronic inflammation
- diabetes
- colon cancer
- allergies
- heart disease
- autoimmune
- mental disorders
Dysbiosis
- an alteration or imbalance in gut microbiome linked to disease
- what came first? disease or gut imbalance? don’t know
What has historically changed the gut microbiome
- industrialization
What impact has industrialization had on the gut microbiome
- decreased diversity of microbes
- increased mucus degradation
- decreased SCFAs
- all lead to risk of chronic disease
4 potential mechanisms for driving disappearing microbiome
- diet - can target this
- sanitation
- antibiotics
- c-sections and formula
RDA for fibre for females and males
- females: 25g/day
- males: 38g/day
What happens if we starve out gut microbes
- mucus barrier is damaged and pathogens break it down
- pathogens have access to epithelial cells and self-eat
How are non-digestible polysaccharides digested
polysaccharides –> oligosaccharides –> simple sugars/SCFAs –> fuel for epithelial cells and signaling molecules
How are dietary and endogenous proteins digested
proteins –> amino acids/peptides –> ammonia, phenols, BCFAs, nitrosamines, H2S, amines –> detrimental to colonic health
Excess dietary protein and gut microbiome
- shifts from carbohydrate fermentation to protein degradation
- don’t know if it is the protein or lack of fibre
2 Tryptophan bioactive metabolites and functions
- indole-derivates: ligands critical for immune responses at barrier sites
- 5-hydroxytrptophan: neurotransmitter involved in gut-brain axis
What can happen with increased consumption of dietary fat and the microbiome
- promotes growth of bile-tolerant microbes –> pro-inflammatory and carcinogenic?
- increased gut permeability allows harmful compounds crossing barrier
- colon cancer, IBS
What can happen with increased consumption of PUFAs and microbiome
- increases abundance of good bacteria
- promotes SCFA production to maintain barrier
- increases diversity
- anti-inflammatory effects
Current health guidelines for healthy guts
- consume vegetables, fruits, whole grains, plant-based protein, fatty fish, fermented dairy products
- consume lean red meat in moderation
- limit high fat dairy and avoid consuming processed meats
3 nutritional supports for microbes
- fermentable fibres
- prebiotics
- microbiota-accessible carbohydrates