Exam 4 (Lecture 45) - Gut Microbiome Homeostasis Flashcards
Where is the largest portion of the gut microbiome located?
Colon (Large intestine)
The gut microbiome contributes to overall _______ and ________.
Health; wellness
What are the benefits of a balanced gut microbiome?
1) Supports brain function
2) Protects the heart
3) Supports longevity
4) Supports kidney function
5) Maintains a healthy weight
6) Maintains a healthy skin coat
7) Helps support immune system
What are the functions of the colon?
1) Production of vitamins (K; required for blood clotting)
2) Fermentation of organic matter that escapes digestion and absorption in the small intestine
3) Bile acids reabsorbed via enterohepatic circulation; also serve as substrates for bacteria
4) Absorption of water, vitamins, electrolytes
5) Storage of feces
6) Defecation
Where is vitamin K produced? What is vitamin K required for in the blood?
Produced in the colon; required for blood clotting
16S rRNA gene sequencing demonstrates > 90% of bacterial belong to which two phyla?
1) Bacteriodetes
2) Firmicutes
Bacteriodetes and Actinobacteria can produce _______ the essential energy source for _________.
Short-chain fatty acids; colonocytes (colon epithelial cells)
The healthy gut bacteria help with: _________ tight junctions, regulating __________, and stimulating _________.
Strengthening; intestinal motility; production of anti-inflammatory compounds
Describe how colonocyte metabolism functions as a control switch, mediating a shift between homeostatic and dysbiotic microbial communities.
During homeostasis, colonocyte metabolism is directed toward oxidative phosphorylation, resulting in high epithelial oxygen consumption.
Consequent epithelial hypoxia helps maintain a microbial community dominated by obligate anaerobic bacteria, which provide benefit by converting fiber into fermentation products absorbed by the host.
Conditions that alter the metabolism of the colonic epithelium increases epithelial oxygenation, thereby driving an expansion of facultative anaerobic bacteria, a hallmark of dysbiosis in the colon.
A balanced microbial ecosystem is crucial for host health and homeostasis. Changes in the gut-microbiome are associated with ______. List the symptoms that can occur if there is an imbalanced microbiome.
Diseases
1) Dementia
2) Heart disease
3) Chronic inflammation
4) Kidney disease
5) Weight loss or obesity
6) Skin problem
7) Digestive issues
Define the following terms: prebiotic, probiotic, and post biotic.
- Prebiotic = Sources of dietary fiber that provide food for beneficial gut bacteria
- Probiotic = Microorganisms (usually bacteria) that are consumed for their health benefits
- Postbiotics = Fermentation activity on prebiotics that produces waste material (byproducts)
Why is using a fecal microbiota transplant (FMT) more effective than a probiotic in a dog with diarrhea?
With FMT the gut is actually seeded with beneficial dog-specific microbes
