16. introduction to the Gut Microbiota Flashcards
(38 cards)
when is our GUT MICROBIOTA ESTABLISHED
in first few years of life
(but fragile)
(especially first 10 days)
our MICROBIOTA CO-EVOLVE with…
the IMMUNE SYSTEM
MICROBIOTA GENE SET is how many times the HUMAN GENOME
150X
MICROBIOTA are IMPACTED by
*DIET
- ENVIRONMENT
- HOST GENOTYPE
- AGE (fragile again later in life)
- DISEASE
- type of birth, type of feed (breastfeed)
- Inflammation
how is a FETUSES FIRST FAECES - MECONIUM
STERILE
no microbiomes
on DAY 2 of life which BACTERIA could be isolated
- COLIFORM BACTERIA eg E. COLI (first colonisers)
- LACTOBACILLI (in breast milk and vagina)
- ENTEROCOCCI
STRAINS of which BACTERIA can be found on DAY 3
BACTEROIDES
which BACTERIA be found on 5TH DAY
BIFIDOBACTERIA
GUT MICROBIOTA SHAPES INTESTINAL…
IMMUNE SYSTEM
how is GUT MICROBIOTA is HEALTHY INDIVIDUALS
- HIGHER TAXONOMIC DIVERSITY (number and relative abundance of species in a community)
- HIGHER GENE DIVERSITY
- Microbial communities are important for DEVELOPMENT and STABILITY of IMMUNITY
- HOST-MICROBIOTA MUTUALISM
- Bacteria CONTROLLED BY the INTESTINAL BARRIER (mucus) and underlying MUCOSAL IMMUNE COMPARTMENT
what is meant by HOST-MICROBIOTA MUTUALISM
2 ORGANISMS of DIFFERENT SPECIED CO-EXIST
& each individual BENEFITS from the ACTIVITY OF THE OTHER
- relationship where both benefit from each other
what are BACTERIA in our GUT MICROBIOTA CONTROLLED BY
INTESTINAL BARRIER and UNDERLYING MUCOSAL IMMUNE COMPARTMENT
name the 6 MAJOR PHYLA (level of classification or taxonomic rank)
90%:
- FIRMICUTES
- BACTEROIDETES
lower numbers:
- ACTINOBACTERIA
- PROTEOBACTERIA (can become pathogenic)
- FUSOBACTERIA
- VERRUCOMICROBIA
what are the DOMINATING BACTERIA in the DISTAL GUT especially Ascending and Transverse COLON
FIRMICUTES and BACTEROIDETES
how is the MUCUS LAYER in the COLON
2 LAYERS
Inner: free from bacteria
Outer: legislator of HOST-MICROBIAL INTERACTIONS (bacteria present)
& CONTINUOUS
2 MUCUS LAYERS in the COLON are ORGANISED by which MUCIN GLYCOPROTEIN
MUC2 MUCIN
which COLON MUCUS LAYER has BACTERIA
OUTER LAYER
WHERE is MUCUS CONTINUOUS / DISCONTINUOUS
stomach?
small intestine?
colon?
CONTINUOUS in STOMACH & COLON
DISCONTINUOUS in SMALL INTESTINE (for efficienct absorption)
why are HIGH FRUIT, LEGUME and FIBRE DIETS beneficial for GUT HEALTH
more GRAM+ bacteria
more saccharolytic species (anaerobic)
(& less pathogenic intestinal bacteria)
HIGH SCFA LEVELS (short-chain fatty acids)
SCFAs are a subset of FATTY ACIDS with how many CARBON MOLECULES
6 OR LESS
SCFAs in bowel
ACETATE
PROPIONATE
BUTYRATE (main source of energy)
SCFAs from bowel are taken up into circulation and then FURTHER METABOLISED by…
LIVER
what can you get from ANUMAL BASED DIET
HARMFUL BRANCHES ISO- SCFAs
where are SCFAs ABSORBED
LARGE INTESTINE
