L-30 Flashcards
What percentage of our cells are human vs microbes?
50%
What are microbiota?
Individual microbial species in a biome (bacteria, fungi, archaea, viruses0
What are the levels of classification of organism (from least to most specific)
- domain
- phylum
- class
- order
- family
- genus
- species
- strain
How many bacterial phyla are there?
92
How many Archael phyla are there?
26
What is the aim of the human microbiome project?
To characterise microbial communities found at multiple human body sites and to look for correlations between changes in the microbiome and human health
What method of microbial community characterisation did the human microbiome project use?
Culture-independant
Where are the areas of interest for the HMP?
- oral
- skin
- vaginal
- gut
- nasal/lung
What are the 5 goals of the HMP:
- To develop a reference set of microbial genome sequences and perform preliminary characterisation of the human microbiome
- To explore the relationship between disease and changes in the human microbiome
- To develop new technologies and tools for computational analysis
- To establish a research repository
- To study the ethical, legal, and social implications of human microbiome research
What is the genetic diversity of an individuals gut bacteria as opposed to the human genome?
50x
What percentage range of the genera, enzyme families and community configurations occupied by healthy Western microbiome has the HMP documented?
81-99%
How many species of microbes does the average person have? How many of these are really common between people?
- 160
- 57
What are the 8 functions of the human microbiome:
- preventing pathogens from being successful
- block colonisation niches
- competing for nutrients (stops pathogens from getting nutrients)
- modifying environments to change virulence factor expression
- making environments actively hostile: producing bacteroicins (antimicrobial) & short chain fatty acids (SCFA)
- lowering pH (vagina)
- cause host to thicken mucus layer
- cause host to upregulate antimicrobial peptides (defensins)
- primes host neutrophils and macrophages
What are the 4 main types of human gut microflora?
- firmicutes
- bacteroidetes
- actinobecteria
- proteobacteria
What area of the body has the highest density of microbes in the human body
The gut
What percentage of the fecal biomass is bacteria?
50%
What does human gut microflora do?
Creates SCFA that modulate our metabolism and effects our defence against pathogens
What are the functions of the gut microbiome?
- synthesise vitamins including B and K
- modulate the immune response
- alter drug delivery- certain drugs don’t work for some people
What are functional foods?
foods claimed to have a health-promoting or disease preventing properties beyond the basic function of supplying nutrients
What do functional foods contain that normal foods do not?
Probiotics
What are probiotics? Give two examples
live microorganisms
- lactic acid bacteria
- bifidobacteria
Why can probiotics be redundant for people?
The bacteria used are naturally occurring in the stomach so if you eat a healthy diet you don’t usually need more
What are the potential benefits of probiotics?
Prevention and treatment of pathogen-induced diarrhoea and urogenital infections
What is a prebiotic?
An ingredient that beneficially nourishes the good bacteria already in the large bowel or colon
