Integration Flashcards
what is the gut microbiome?
microbiota and their genetic capacity (microbes and what they can do)
what are 4 essesntial functions of gut micrbobes?
1) nutrient aquisition
2) immune regulation
3) pathogenic protection
4) metabolic signaling
how are “we” separated from the gut microbiome? why is this needed?
the microbes are separated from intestinal cels by a layer of mucus
-the mucus layer prevents the microbes from attacking the immune cells, acting as a control to only allow a small passage of micorbes
explain the role of the gut microbiome in nutrient aquisition:
the food don’t digest in the small intestine become availible for microbes in the gut
-this alows us to breakdown nutrients from the undigested food
how does gut physiology explain the interactions with the microbiome in herbivores vs carnivores?
herbivores: have large fermentation chambers to increase the microbiome and be able to digest food we dont have enzymes for
carnivores: contain all the enzymes needed to breakdown the food they eat
provide 3 examples of SCFA? what is their function? provide 6 examples of how do they do this?
Acetate, propionate, butyrate:
they act as signaling molecules in the body
-substrates for molecules
-fuel for epithelial cells
-improve barrier function
-reduce inflammation
-increase satiety
-improve insulin sensitivity
what is dysbiosis? why is this controversial?
an alteration in the gut microbiome that is linked to disease
-it is hard to determine what occured first, the disease or the gut alteration
what impact does industrialization have on the gut microbiome?
it decreases the diversity as compared to non-industrialized populations
explain the fibre gap in non-industrialized, acestral, recommended and current fiber intake?
ancestral diet: > 100g day
Non-industrial diet: 60-100g / day
recommended intake: 25g/day F 38g/day M
current intake: 12-20g/day
what happens when we dont feed our microbes? where will they get their food from if not from fibre?
reduced intake of dietary fibre reduces the survival of a large number of microbes, once these microbes are lost they do not come back, evern with the intake of a high fibre diet
if we starve our microbes from fibre, they will breakdown the mucus layer in order to use glycoproteins for energy
-allowing the microbes to interact with the epithelial cells, causing an immune response
how can excess protien intake impact the gut microbiome? what harmful products are made?
the shift from carb sources to protein sources causes protein degradation which decreases the abundance of beneficial gut microbes
-produces BCFAs and ammonia
-decreases SCFAs
what do gut microbiota do to tryptophan?
convert it into ligands for receptors involved in immune response and 5-hydroxytryptophan which is a NT in the gut brain axis (beneficial changes)
what impact does increased consumption of dietary fat have on the gut microbiome?
1)promotes growth of bile-tolerant microbes
-considered carcinogenic (convert primary bile acids into secondary)
2) increases gut permeability
-compounds cross intestinal barrier
provide an example for how a change in diet can impact colon cancer risk
what impact does PUFA have on the gut microbiome?
it has similar effects as fibre
1) increases health-promoting bacteria
2) increases SCFA production
3) increases diversity
4) mediates anti-inflammatory effects
do dietary guidlines align with knowledge on how diet influences the gut microbiome?
Yes
what are targeted strategies to modulate the gut microbiome? what is the challenge with this?
1) nutritional support (fermentable fibres, prebiotics, microbiota-accessible carbs)
2) introduction of health promoting microbes (probiotics, live biotherapeutics, fermented foods)
The challenge is that we are all different and the same diet for one person may have a different effect
how can nutrition be personalized based on the gut microbiome?
prediction of individual GI responses to food postprandially may allow for more precise nutrition
what can we do to reduce the burden of cancer?
1) early detection and adequate treatment are key
2) screening
3) early diagnosis
-many cancers have a high chance of being cured if detected early
what does healthy metabolism mean?
a state of operational function (homeostasis) of every cell in the body
-proper cell function and mitochondira function
what 2 main factors cause tumour developmemt?
1) genetic alterations
2) lifestyle factors
what is the warburg effect?
a specific type of metabolism in cancer cells where it will use anaerobic metabolism even if O2 is availible in order to increase the rate of growth
-produces less ATP but is faster, decreases harmful by-products and help adapt to hypoxic environments
explain how cancer can cause metabolic reprogramming for protein, glucose and lipids?
1) cancers will increase protein synthesis to supprt rapid growth
2) GLU is highly consumed for energy and the by-products are used to produce nucletides for DNA synthesis
3) Cancer cells enhance lipid synthesis to create new membranes for new cells and support signaling pathways