The Human Microbiome Flashcards
What is the ratio of human to microbial cells in the body?
1: 1
- Half of what happens in the body is catalysed by microorganisms
What is a microbiome?
The complete collection of microorganism and their genes within a particular environment
What is a microbiota?
Individual microbial species in a biome - bacteria, fungi, archaea and viruses (anything that has DNA)
What are the goals of the HMP (Human microbiome project)?
- Developing a reference set of microbial genome sequences and to perform preliminary characterization of the human microbiome (for ‘normal’ microbiome)
- Explore the relationship between disease and changes in the human microbiome
- Develop new technologies and tools for analysis
Establish a resource repository - Study the ethical, legal and social implications of doing this research
How many microbial species are there in the human microbiome?
10,000
What area in the body has the highly density of microbial species?
The gut
500 - 1000
What did the HMP find out about the human microbiome?
- Strong niche specialisation within and among individuals (different sites have different microbes)
- Diversity and abundance of each habitat’s signature microbes vary widely even among healthy individuals
- Types of microbes vary between individuals due to the environment they are exposed to.
- Gut samples are similar amongst humans as we all eat around the same thing = gut does the same thing in all of us
- Although there is variation, core groups of organisms can be identified for different sites
How many of the microorganisms in the healthy western microbiome were HMP able to document?
81-99% of the general enzyme families and community configurations
Can microorganism be replaced with others in the human microbiome?
Yes, as long as they perform that same function for the body
What type of communities mostly make up the human microbiome?
Firmicutes
Bacteroidetes
Actinobacteria
Proteobacteria
- Few bacterial groups that dominate, but within this there are a lot of species and strains
- The same 4 group dominate in the human gut, but the proportions of them are going to change from place to place
What does the change in pH of the human gut mean for microbes?
They will have different selection pressures so there will be different microbes.
- Amounts of microbes will increase down the human gut
- Also changing the aerobic status as you go down the gut
Where in the body is the human gut?
Runs from the mouth to the anus - the gastrointestinal tract/ digestive tract
What percentage of the human microbiome associated microbes have not been cultured yet?
20-80%
How much of human faeces are microbes?
50%
What are functional foods?
Food claimed to have a health-promoting or disease prevent property beyond the basic function of supplying nutrients
