Microbiomes - L4B Flashcards
what is a microbiome?
functional collection of microbes at an environmental site
what is a microbiota?
type of organisms present at all environmental site
the name for good microbiomes?
symbionts
the name for bad symbionts?
pathogens
importance of the microbiome?
- Development of new therapeutics
- Personalised therapies
- Probiotic treatment
where is symbiotic bacteria found?
- oral cavity
- gut
- skin
what was the stomach long thought to be?
- sterile
- now known to host a diverse microbiome
what are some core microbes of the stomach?
- prevotella
- streptococcus
- lactobacillus
what is the large intestine home to?
ver large numbers of bacteria and some archaea
what are the 3 enterotypes of the gut microbiome?
prevotella
bacteroidetes
ruminococcus
why is an altered endocrine function bad?
increased insulin resistance
alteres glucose metabolism
causes diabetes
why is modulation of lipid metabolism bad?
obesity
hypertension
cardiovascular disease
why is production of neurotransmitters bad?
mental health problems
3 functions of oral microbiome?
- prevent dental cavities originating
- control vascular health
- aid normal development of immunity
what was the lung microbiome thought to be?
- sterile
- is NOW known as a diverse microbial habitat
what affects the development of lung microbiome?
- geographical location
- environmental conditions
why is it difficult to sample lower airway microbiome?
due to issues with contamination, access, invasiveness
- where to sample and transport of microbial samples
name 2 diseases associated with lung microbiome
- rhinovirus
- influenza
where is bacteria trapped when inhaled?
- mucous secretions
main bacteria in upper respiratory tract?
- streptococci
- staphylococci
what is the lower airway microbiota dominated by?
actinobacteria
proteobacteria,
how many bacterial genomes in the lower airway?
approx 2000 bacterial genomes per cm^2
what is seen in diseased airways?
candida
penicillin
what is seen in cystic fibrosis and asthma ?
Malassezia
what can an unstable microbiome leads to>
increased risk of infection and disease
Number of infections at early age affects later life events
Dynamic interaction between different microbes
what do microbiomes release?
products to make microbes more susceptible or resistant to immune attack
what do viruses break down?
epithelial barriers
what do the broken down epithelial barrier increase?
risk of bacterial infection
what do bacteria upregulate?
adhesins
why does priming immune cells with bacteria make them more resistant to viral infection?
- Shapes immune responses, inflammation and tolerance
- Influences bacterial communities
is the vaginal microbiota diverse?
no
which bacteria presents as lower pH and regulate immune function
lactobacillus acidophilus
what other bacterias are in the vaginal microbiome
staphylococci
E. coli
what dominates the four vaginal endotypes?
lactobacilli
why is the final vaginal endotype different?
fewer lactobacilli but more anaerobes
how does lactobacilli decrease vaginal pH?
- oestrogen produced
- acid produced and pH drops
is lactobacilli gram positive or negative?
positive
how many bacteria in the skin?
Approx. 1 million bacteria per cm^2
describe two changes in the microbiome that drives disease
Dental cavities-> changes in oral microbiome on a community level
Inflammatory bowel disease -> failure to tolerate normal microbiota early in life
