Microbial ecology of human gut Flashcards
What is gnotobiology?
Studies of germ-free animals, born and raised under sterile conditions
What are the abnormalities that develop in the intestines in germ free mice?
-Shallow intestinal crypts, fewer proliferating stem cells
-Lower vascularisation of villi
-Immature Peyers patches
-Greatly enlarged caeca
-Longer lifespan
How is immune homeostasis maintained in the gut?
Through balancing of pro- and anti- inflammatory signals
What happens in failure in mucosal firewall?
-Translocation of pro-inflammatory bacteria and induction of chronic inflammation - Inflammatory bowel disease
How does the immune system keep microbiota at bay?
By building mucosal firewalls
What is the biotope?
refers to environmental conditions inside a biome
What is the biota?
Refers to collection of all life forms
Microbiome vs Metagenome?
Microbiome : a characteristic microbial community occupying a reasonably well defined habitat which has distinct physio-chemical properties - m/o + theatre of their activity
Metagenome - the collection of genomes and genes from the members of a microbiota
What is commensalism?
One benefits and the other is not significantly harmed or helped
What is parasitism?
The parasite benefits while the hold is harmed
What are Human milk oligosaccharides (hmos)?
Branched-chain glycans containing lacto-N-biose and lacto-N-tetraose as basic subunits
-These carbs cant be metabolised by a child so substanmce for bifidobacteria
-Proliferation of bifdobacteria creates a barrier to colonisation by pathogens
What are key mutalistic bacteria in the vaginal microbiome?
Lactobacilli
-normal levels of estrogen promote accumulation of glycogen in b´vaginal epithelium - nutritive substrate for lactobacilli
What can prototrophic bacteria grow on?
A single carbon source, inorganic nitrogen source, and a handful of salts and trace elements
