Gut Microbiota Flashcards
1
Q
What are commensals?
A
Organsims, mainly bacteria that live in a mutualistic relationship with us
2
Q
What are the intrinsic factors that affect the microbiome?
A
- genetics (inherited and mutations)
- gene regulation
- epigenetics
- proteomics (modification of expression of proteins)
3
Q
Extrinsic factors that affect the microbiome?
A
- pathogens
- drugs: antibiotics
- diet
- medical history
- environment: (allergens/behaviours)
4
Q
Do foetuses have gut flora?
A
no they are germ free
5
Q
When does the gut flora develop?
A
-At birth most people are colonised by dozens of species of bacteria which remain with organism until death
6
Q
What is a parasite?
A
A eukaryotic organism which uses the gut to benefit itself without providing any benefits to the host. e.g tapeworm
7
Q
How does the healthy gut flora protect the host?
A
- layer formation of flora to protect against pathogens
- waste product formation which can produce products that protect against pathogens
- immune stimulation
8
Q
What can cause damage to the microbiome?
A
- physical destruction e.g burns
- host factors (e.g reduced peristalsis or immune suppression)
- antimicrobial drugs
9
Q
Why are normal gut flora located in particular areas?
A
- most bacteria are specifically adapted to life in one particular niche (normal flora exhibit tissue preference)
- most bacteria able to specifically colonise a particular surface/tissue using their own surface components as specific ligands for attachment to specific receptors
10
Q
How do we protect ourselves against harmful bacteria?
A
- Mouth: flow of liquids (saliva, drinking), lysozyme (tears), normal flora
- oesophagus: peristalsis, flow of liquids
- Stomach: low PH
- Small intestine: peristalsis, flow of liquids, shedding of epithelium, IgA, mucus, Peyer’s patches
- Large intestine: normal flora, peristalsis, shedding of epithelium
