1
Q
What is the gut microbiome
A
- microbes and what they can do
2
Q
Types of gut microbes
A
- bacteria, fungi, protozoa, archaea, viruses
3
Q
6 essential gut microbe functions
A
- nutrient acquisition
- immune regulation
- protection from pathogens
- metabolic signaling
- gut motility and development
- host metabolism
4
Q
3 layers of gut
A
- microbes (most densely populated)
- mucus layer (sterile)
- intestinal cells
5
Q
Nutrient acquisition
A
what we eat and do not digest or absorb in the small intestine becomes available for gut microbiome
6
Q
Microbiomes of herbivores vs carnivores
A
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
7
Q
Short chain fatty acids produced from fiber fermentation
A
- acetate
- propionate
- butyrate
8
Q
SCFAs function
A
signaling molecules
- substrates for microbes
- fuel for epithelial cells
- improve barrier function
- reduce inflammation
- increase satiety
- improve insulin sensitivity
9
Q
We have a _____ relationship with out gut microbiome
A
- symbiotic
10
Q
Diseases from gut dysbiosis
A
- obesity
- chronic inflammation
- diabetes
- colon cancer
- allergies
- heart disease
- autoimmune
- mental disorders
11
Q
Dysbiosis
A
- an alteration or imbalance in gut microbiome linked to disease
- what came first? disease or gut imbalance? don’t know
12
Q
What has historically changed the gut microbiome
A
- industrialization
13
Q
What impact has industrialization had on the gut microbiome
A
- decreased diversity of microbes
- increased mucus degradation
- decreased SCFAs
- all lead to risk of chronic disease
14
Q
4 potential mechanisms for driving disappearing microbiome
A
- diet - can target this
- sanitation
- antibiotics
- c-sections and formula
15
Q
RDA for fibre for females and males
A
- females: 25g/day
- males: 38g/day
16
Q
What happens if we starve out gut microbes
A
- mucus barrier is damaged and pathogens break it down
- pathogens have access to epithelial cells and self-eat
17
Q
How are non-digestible polysaccharides digested
A
polysaccharides –> oligosaccharides –> simple sugars/SCFAs –> fuel for epithelial cells and signaling molecules
18
Q
How are dietary and endogenous proteins digested
A
proteins –> amino acids/peptides –> ammonia, phenols, BCFAs, nitrosamines, H2S, amines –> detrimental to colonic health
19
Q
Excess dietary protein and gut microbiome
A
- shifts from carbohydrate fermentation to protein degradation
- don’t know if it is the protein or lack of fibre
20
Q
2 Tryptophan bioactive metabolites and functions
A
- indole-derivates: ligands critical for immune responses at barrier sites
- 5-hydroxytrptophan: neurotransmitter involved in gut-brain axis
21
Q
What can happen with increased consumption of dietary fat and the microbiome
A
- promotes growth of bile-tolerant microbes –> pro-inflammatory and carcinogenic?
- increased gut permeability allows harmful compounds crossing barrier
- colon cancer, IBS
22
Q
What can happen with increased consumption of PUFAs and microbiome
A
- increases abundance of good bacteria
- promotes SCFA production to maintain barrier
- increases diversity
- anti-inflammatory effects
23
Q
Current health guidelines for healthy guts
A
- 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
24
Q
3 nutritional supports for microbes
A
- fermentable fibres
- prebiotics
- microbiota-accessible carbohydrates
25
3 introductions to health-promoting microbes
- probiotics
- live biotherapeutics
- fermented foods
26
The gut microbiome is ____ between individuals
- vastly unique and different composition
- foods react different with everyone
27
What is cancer
- cellular abnormality
- uncontrolled growth
- spread to close tissues and distant organs
28
Cancer risk factors
tobacco, BMI, alcohol, low fruit + veg, low PA, air pollution
29
Reducing the burden of cancer
- prevention
- early detection
- early diagnosis
- screening
- treatment
30
Effects of mitochondrial damage
- turns off tumor suppressor genes
- disrupts protein expression (tumor suppression, DNA repair, cell cycle regulation)
31
Genetic vs epigenetic variables
- genetics - load the gun
- epigenetics - pull the trigger
32
Cancer cell energy needs
- demand for nutrients is much higher for rapid growth
- process energy, protein, carb, lipids differently
33
The Warburg Effect
- no oxidative phosphorylation (with or without O2), shifting to lactate production and producing 2ATP
- less efficient but faster
- less harmful by products
- adapt to hypoxic environments
34
How does cancer reprogram protein metabolism
- increase protein synthesis
- rely on glutamine for building
35
How does cancer reprogram carb metabolism
- heavily consumed through glycolysis
- byproducts used in DNA and RNA synthesis
36
How does cancer reprogram lipid metabolism
- enhance lipid synthesis to create membranes for new cells and support signaling pathways
- enzymes involved are overactive
37
Cancer impacts on the body
1. stimulates secretion of factors that interact with immune system
2. inflammatory response cytokines
3. imbalance of neuropeptides and body composition
4. TTT: symptoms decrease food intake and activity
5. weight loss and muscle wasting
38
4 impacts on body from cancer
- malnutrition
- cachexia - loss of muscle and fat mass
- sarcopenia - muscle and fat loss not depended on nutrition
- frailty - weakness, slow, balance impairment
39
How to screen for malnutrition
GLIM criteria
- phenotypic (weight loss, BMI, muscle mass)
- etiologic (food intake, disease, inflammation)
40
How to screen for cachexia
Fearon criteria
- weight loss, food intake, inflammation
41
How to screen for sarcopenia
EWGSOP 2
- muscle function, handgrip, chair stand, muscle quantity/quality
42
How to screen for frailty
Fried 5 criteria
- weight loss, handgrip, poor energy, slowness, low PA
43
Cancer care steps
- nutritional evaluation
- oral supplements (intake <70%)
- enteral/parenteral nutrition (intake <60%)
- individualize assessment
- treatment for side effects
- follow up
44
Good cancer fighting foods
- anti-inflammatory foods
- omega-3 fatty acids
- antioxidants
45
Regular exercise will improve fitness causing
- physiological adaptations
- over load principal
46
Health physiological state includes
- respond to infections
- anti-inflammatory state
- function of organs and cells
- high turnover of energy stores
47
Greater lean tissue and increased % of lean tissue elevates
- basal metabolism
48
Cardiorespiratory fitness
- capacity to make ATP to maintain activity
- VO2 max
- increased by durations of activity just sub-VO2 max
49
Strength
- muscle capacity and endurance
- hypertrophy of muscles created adaptation
50
Flexibility
- range of motion
- increases physics of activity
- enhances speed, agility, energy use
51
Healthy body comp ranges
- male 10-20%
- female 20-30%
52
Canadian guidelines for exercise
- 150 min/week of moderate to vigorous aerobic PA
53
Exercise intensity and energy store use
- moderate - longer, fatty acids, glucose, anaerobic
- high - more glucose dependent, aerobic
54
What is fatigue caused by
- lactic acid accumulation
- lower oxygen availability
- change in muscle blood gases
- less glucose availability
- glycogen depletion (onset of overwhelming fatigue)
55
Glycogen stores last
1 hour of vigorous activity
56
Dehydration and hypo-natremia
- water loss sufficient to reduce blood volume
- vasoconstriction, heart rate increases, reduced cardiac capacity
57
Untreated dehydration causes
- core body temp to rise
- imbalance of electrolytes
- cramps, heat stroke, low BP, confusion, loss of consciousness
58
Hydration recommendations
- 500ml 4h prior to exercise
- 200-300ml/15 min during exercise
- >1h electrolytes consumed with water
- 500ml for every 0.5kg lost after exercise
59
Eating prior to exercise
- 2-4h before
- smaller volume
- CHO-rich
- low in protein and fat
60
Eating during exercise
- >60 min maintain glucose
- banana, energy bar, gel, fluid energy
- combinations of saccharides is more readily absorbed
61
Eating after exercise
- replace fluid loss first
- CHO and protein rich foods < 30 min
- balanced meal 2-6h after
62
Fasted training
- lower glycogen can stimulate fat utilization
- can increase cardio capacity (VO2 max)
- works better for endurance training
63
Fat adaption
- using FAs more than CHO (keto, atkins)
- requires training to adapt
- eating more fats than CHOs
- brain often does not like this
64
Caloric restriction
- reduce weight and extend life span
- improve cardiometabolic risk factors, insulin sensitivity, mitochondrial function
- difficult to sustain
- key mechanism responsible for metabolic switching
- 15-40%
65
Intermittent fasting
- fasting every day 12 hours or longer
66
Alternate-day-fasting
- consume no calories on fasting days alternating with unrestricted food intake days
67
Alternate-day modified fasting
- consuming less than 25% of baseline on fasting days alternating with unrestricted food intake days
68
Time-restricted feeding
- restricted food intake to specific period of day
- typically 12 hours
69
Periodic fasting
- fasting 1-2 days/week
- normal food intake 5-6 days/week
70
Metabolic switching
- shift from utilization of glucose to fatty acid derived ketones
- 12-36 hours after food consumption
- accelerated adipose tissue lipolysis
- sustain function of muscle and brain during fasting to preserve muscle mass
71
Ketogenic diet
- high fat
- moderate protein
- low carb
- increased HDL, decreased TG, changed in LDL particle size
- weight loss, less CVD risk, reduced appetite, changes in appetite hormones
72
Keto diet side effects
- dehydration, lethargy, kidney damage, constipation, micronutrient deficiencies, social isolation
73
Isocaloric ketogenic diet
- calorie restriction? no
- carb restriction? yes
- ketosis? yes
- body weight loss? no
74
Low calorie diet
- calorie restriction? no
- carb restriction? no
- ketosis? no
- body weight loss? yes
75
Very low calorie diet
- calorie restriction? yes
- carb restriction? no
- ketosis? no
- body weight loss? yes
76
Very low carb, high fat, ketogenic diet
- calorie restriction? no
- carb restriction? yes
- ketosis? yes
- body weight loss? yes
77
Very low calorie ketogenic diet
- calorie restriction? yes
- carb restriction? yes
- ketosis? yes
- body weight loss? yes
78
Yo-yo diet
diet --> metabolism slow down --> end of diet --> normal eating --> weight gain --> diet
79
GLP-1 is released from where
large intestine
80
Action of GLP-1
inhibits NPY secreting neurons
inhibits hunger
81
What is ozempic
GLP-1 receptor agonist
82
What does GLP-1 receptor agonist do
- increases insulin secretion
- decreases hepatic glucose production
- improves fasting and postprandial glucose
- delays gastric emptying
- reduces food intake due to satiety
83
What mass is lost on ozempic
- 8% total fat mass
- AND 5% total muscle mass
84
Possible side effects
- gastrointestinal disruptions
Nutrition 301
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