Human microbiome 2 Flashcards
(26 cards)
WHich information cannot be seen by 16srRNA sequencing?
Strain information or functional information
What is some functional info that wont be seen via 16SrRNA sequencing?
Differences in virulence between strains
How can fungi be profilled?
ITS sequencing–> similar to 16SrRNA
What is not present in metagenomics that may be present in other sequencing techniques?
Amplification
Benefit of metagenomics over other sequencing that uses amplification?
Functional indo
Which functional info can metagenomics pick up?
antimicrobial resistance, metabolism, strain type
Downside of metagenomic sequencing?
Low abundance sequences are not usually picked up
need a deeper level of sequencing (expensive)
What is alpha diversity?
Tries to measure the richness and evenness of the microbiome–> how many species and the evenness of the species
What is beta diversity?
a measure of the dissimilarity between two microbiomes
Pros and cons of ilumina?
Sequences all of the genome, but in small snippets so difficult to reconstruct them
How is identification of bacteria via sequencing improving?
Varying GC content, frequency at which nucleotides, dinucleotides and trinucleotides are used
What are metagenomic assembled genomes?
Libraries of genomes of bacteria assembled via metagenomics
When are a person’s first microbes picked up?
As they exit the birth canal
Which bacteria first colonise a person, and what is their role?
Bifidobacteria–> switch on the immune system
Why is the foetus not immunocompetent?
It would be reacting to maternal antigens
Difference between vaginal and cesarean delivered babies?
Initial microbiota
What are gnotobiotic mice?
Mice delivered via c-section that are raised in germ-free environments
Outcome of gnotobiotic mice?
Dont develop properly–> immunocompromised
Why is diarrhoea the main side effect of most antibiotics?
Antibiotics wipe out 95% of gut flora
Difficulty of looking at a disease and its correlation with microbiome characteristics?
Cant work out whether disease causes microbiome difference, or the thing that causes the disease also causes the difference (e.g. lack of exercise/poor diet causes type 2 diabetes which effects the gut microbiome
Or does the microbiome cause the diabetes)
Key digestion function of the gut microbiome?
Digestion of dietary fibre that humans cant digest without the microbes
Leaky gut cause?
Microbes/microbial products seeping across the gut into surrounding tissues–> v inflammatory
Leaky gut outcome?
chronic inflammation in the tissues around it
Why do westernised societies have a higher incidence of metabolic diseases?
Lack of dietary fibre
