L14- Gut Microbiota Changes Flashcards
What are probiotics
Lige organisms eg bifudo and lactobacillus in yoghurt which feed on prebiotics
What srw prebiotics
Indigestible fibre eg from fruit or potatoes to promote digestion and heslthy gut
Give examples of how disease change microbiots
Roseburia cox et al 2013- reduced in type 2 diabrtes whcih sffects appetite,and insulin sensitivity etc
Or bifido in sha 2013 - reduces inflammation and uc symptoms
Waht js rhe largest immune organ
The gut. Has most immune cells
Which 2 layers of muscle does it have
Circular/inner and longitudinal
What are corcular for
Peristalsis
What is the mcuosal smooth muscle called
Mucosae muscularis
What is the connrctive tossue around mucosa
Submucosa
What does serosa have (outer layer of gut£
Epithelial with lubricant
Which part of gut forms some peritoneum
Serosa
Where is the mucosal layer biggest and why
Li/colon as this is nutrient poor so fermentation occurs more = more scfa too
Why is stool not representativr of guy
Only microbiota at didtal colon and rectum. And not necessarily associated with mcuosa
What is the perfrct scenario for stool sampling
Frozen stool samples and aequwnced asap for functional analysis
What is the solution to problmeatic sotrage of stool in freezers
Buffered stool which presevred it for 60 days
What is the ossue with buffered stool
It kill microbiota and so cant do functional analysis, only sequencing
Which tools are used for sampling of mucosal epithelial
Brushes and biopsies
What is yood withbusing these eg in ibd patients
Can compare samples from inflamed areas vs non inflamed
Why sould you need to amplify the samples gia 16s rrna
Low biomass in samples
Why are samples not taken after colonscopies for 2 weeks
Because the bowels get cleaned gia diarrhoea losing microbiota
Name 3 bacteria whichd egrade mucus in fermentation tonproduce scfa (but also issues)
B theta, precotella, Akkermansia muciniphila
Name some impacts of butyrate
Anti cancer (chen 2018)
Glucose and energy metabolism
Consumtion of o2 by colonocytes via b oxidation
Mucin (blacher 2017)
Why is consumption of oxygen of coloncytes important
Holds the aerobic va anwrobic barrier for the obligate anaerobes
Which scra is needed for gluconeogenesis, appetite reg, t regs
Proprionate
What does acetate do which xan cause obesity
Lipo genesis
Which article disxusses micorbiota and obesity
Chambers et al 2018
Which bacteria associated with plsnt diets are lowered eg prevotella
Firmicutes
Which are associated with hfd
Bacteroidetes
Which is suggetsed to be a therapy for obesity/diabetes
Akkermansia muciniphila
Which scfa does it produce
All 3
Which hormones does proprionate increase to refuce appetite (chambers 2018)
Pyy and leptin
Which hormone from priprionate increases insulin release
Glucagon like peptide 1 GLP1
What is buttrate correlated to (meaning low firmicutes is an issue)
Improved insulin sensitivty
Tive some examples of bacteria living in nuteient rich si
Proteobacteria ef exoli, lactobacillus
Why isnt fmt limited to genetics
Genetics was found not to really impact on microbiota
In the development period -3-14 months. What is tiven by breastfeeding
Bifido, lactobacillus, lower ecoli proteobacteria = good
Which bscteria is most stable overtime
Bifido
Which bacteria is less stable overtime
Clostridia (firmicute)
Do bacteroidetes stabilise ober yime
Yes when given solid food
How much does microbiota reduce before colonsocpy
31 fold
Which article discusses the overcoming of colonisstion resistance by bacteria
Kamada 2013
How does b theta cause both ehec and salmonella growth
Fucose releaae from mucon iupregs lee and t3ss in ehec
Succinate = cdifficile and salmonella growth and mucinase by ehec
What do commensals release which is used to generate tetrathionste as an aea by salmonella so it can use ethanolamine
H2s hydrogen sultide
What does ehec use an an aea
Nitrates for nitrate resp (trom duox2 for h peroxide, nos to form nitrates, via inflammation)
Whoch thing from eli cells in inflammation only can blooc iron of commensals but not salmonella
Lipocallin 2. Blocks fommensal sideorophore not salmonellas
What donjnates over firmicutes in western diets with less plant degrading enzymes
Bacteroidetes
How does c diff spread
Spores and faecal oral route
Give an outbreak of mortailit by c didf and why
Quebec 2000
Due to tcdC gene which allowed unrestricted toxin produced
What is most used antibootic for it
Vancomycin for relapses and severe eg diarrhoea
What type of antibiotic is fidaxomycin
Macrocyclic. Blocks rna polymerase of c diff
What is it for
Sustained and less recurrwnt infections more thwn vancomycin
Why is fmt used
Bacteria which outcompete eg sach biulardii and thuringiensis
How is fmt given
Endoscopy or colonscopy
What does it need to be screened for
Gisrdia and c diff
What is the cure rate compared to bancomycin
80-90 vs 30
What are the issues with fmt
Weight gain due to different way it affects lipid and glucose metabolism
