Human microbiome Flashcards
What is the microbiome?
the collection of microbial genomes in a niche/population
What does the microbiome include?
Bacteria (incl. archea) fungi, viruses, phage(?)
What are microbiota?
The microbes in a niche/population (the individual cells)
Where in the body are microbiomes found?
Gut, skin, genito/urinary tract, respiratory tract
Processes that microbiomes are important in?
Digestion, skin health, vaginal health, overgrowth of pathobionts-> disease
Why was a lot of the microbiome characteristics unknown?
Culture conditions are difficult to replicate in vitro
What allowed us to learn more about microbiome composition, without needing culture?
High throughput DNA sequencing
Which RNA sequencing revolutionised the study of microbiomes?
16S rRNA
Use of 16srRNA sequencing?
identify and classify bacteria in a sample by analyzing a specific part of their 16S rRNA gene
Two main takeaways from initial DNA and RNA sequencing of peoples microbiomes?
Biodiversity was huge
Microbiomes are v variable among people
What can influence a persons microbiomes?
Ethnicity, age, diet, sex, owning pets, geography, time of day
Which microbiomes was the Human Microbiome Project looking to characterise?
Gut, vagina, skin, mouth and resp tract
Aim of Human Microbiome Project?
allow identification of variation with age, sex, nutrition, environment, medication, race AND DISEASE
Setup of the Human Microbiome Project?
250 volunteers (2 US cities)
Sampled at 15/18 anatomical sites
9 oral, 4 skin, 1 nasal, 1 stool, 3 vaginal
What was done with the samples collected for the human microbiome project?
16SrRNA samples–> identify the bacteria present at a taxonomic level
Difference in bacterial ID in human microbiome project?
some can be identified down to the species level, others only the family or genus level
Non-scientific implications of human microbiome project?
Ethical, social and legal (data use and sharing etc)
Initial human microbiome project findings?
biodiversity is massive, >10,000,000 genes
3500-35000 species
What was the main determinant of bacteria present in the HMP?
Body site
Individual characteristic that was a strong determinant of microbiome composition?
Race/ethnicity–> genetics/environment?
Which bacterial species were observed in all individuals in the HMP?
none
Which body site exhibited the greatest microbial diversity?
GIT, including oral
Which body site exhibited the least microbial diversity?
Which body site exhibited the greatest microbial diversity?aginal–> around 6
Mainly lactobacillus
Role of lactobacillus in the vagina?
Generate lactic acid–> acidic pH to eliminate invasion by other microbes
