Gut Microbiots Flashcards
which part of the GI tract has the most bacteria
large intestine
change in oxygenation through GI tract
increasing anaerobic
approximate population along tract
stomach - 10^4
SI - 10^8
LI - 10^10
what does facultative anaerobic bacteria mean
can grow in aerobic and anaerobic
what does obligate anaerobic bacteria mean
can only grow in anaerobic
what two bacteria are present in almost all of the GI tract
streptococcus and lactobaccilus
where do lactobacillus and streptococcus become not prominent
distal ileum and colon (end of tract) when it becomes too anaerobic
what type of anaerobic bacteria are prominent at start of tract
facultative
what type of anaerobic bacteria are prominent at end of tract
obligate
what are the dominant bacteria in the colon
bacteriodes, clostridium, bifidobacterium and enterobacteriaceae
total number of bacteria in gut
> 100 trillion weighing 200g
what is the genus and family of clostridium difficile
genus = clostridium family = clostridaceae
what type of classification is the name clostridium difficile
species
what foods do we need bacteria to digest
fruit, vegetables, whole grains and pulses
benefit of fibre for stools
bulks out the faeces and helps their passage
bacterial fermentation maintains a slightly acidic/alkaline pH
acidic
fatty acid products of bacterial fermentation
butyrate, propionate and acetate
purpose of butyrate
cell growth and regeneration
purpose of propionate
gluconeogenesis and satiety signals
purpose of acetate
lipogenesis
products of microbial fermentation
short chain fatty acids, gases, branched fatty acids and a bunch of random molecules
what type of metabolism produces more branched short chain fatty acids, protein or carbohydrate
protein
microbial defenses against pathogens
barrier against them, out-competing them, producing compounds to kill them, inhibition by pH 6
true/false in normal gut physiology bacteria penetrate into the epithelium
false - they should normally be kept away by mucus layer, any penetration is met by a macrophage
true/false some bacteria are anti-inflammatory and some are pro-inflamatory
true
what disease can be caused when gut microbiota get into the blood stream
sepsis
what features of microbial population are seen in IBD
increased mucosal bacterial overload, reduced diversity
can antibiotics help in IBD
yes, it has some efficacy in reducing symptoms
is there any bacterial difference between areas of inflamed and non-inflamed bowel
no
firmicutes are reduced/increased in ulcerative colitis
reduced
effect of an inflamed gut on bacterial diversity
reduced diversity with increases in enterobacteriaceae
2 things which increase enterobacteriaceae
antibiotics and inflammation
what medications are used to boost a particular bacteria
prebiotics
how can you reduced enterbacteriaceae numbers
reduced antibiotic use
what is a prebiotic
a substrate that is selective for host microorganisms for health benefit
what is a probiotic
a microorganism which brings a health benefit (think yogurts)
geography problem with antibiotics
80% of antibiotics given to livestock reach manure unchanged and enter into water and DESTROY NATUREES
what is FMT used in
when antibiotic therapy doesn’t work for C. Difficile
only approved and effective in c. diff. no evidence in UC
what is FMT
faecal microbial transplantation
criteria of donor for FMT
sensitive to antimicrobials, easy to culture and gut commensal bacteria
