Human Microbiome

Question 1

What is a microbiota?

Answer 1

The microbial taxa of organisms that reside in or on a host or specified part of a host
- A list of species

Question 2

What is a microbiome?

Answer 2

Collective genomes of all the organisms that reside in or on a host
- A list of genes

Question 3

What part of the body are hotspots for microbial life?

Answer 3

Nasal tract 
Oral tract 
Skin 
Gastrointestinal tract 
Urogenital tract

Question 4

What are the three stages of life in which our microbiota is introduced?

Answer 4

As a fetus
As an infant
As a toddler

Question 5

How do we gain microbiota as a fetus?

Answer 5

Gut microbiota of mother
Vaginal infection of mother
Vaginal or cesarean delivery

Question 6

How do we gain microbiota as an infant?

Answer 6

Through milk consumption
Antibiotics
Environment
Solid food introduction

Question 7

How do we gain microbiota as a toddler?

Answer 7

Diet

Question 8

What are the main two microbial groups found in and on our body?

Answer 8

Bacteroidetes

Firmicutes

Question 9

What are the features of bacteroidetes?

Answer 9

Gram negative
Anaerobic
Non-spore forming

Question 10

What are bacteroidetes specialists at degrading?

Answer 10

High molecular weight organic matter

- Proteins and carbohydrates

Question 11

What is the main human genera of bacteroidetes?

Answer 11

Bacteriodia

Question 12

What are the features of firmicutes?

Answer 12

Gram positive
Cocci or rod
Range of oxygen sensitivities

Question 13

What do firmicutes produce?

Answer 13

Short chain fatty acids

Question 14

What are the main human genera of firmicutes?

Answer 14

Clostridia
Bacilli
Mollicutes

Question 15

What is the main route of entry for inhaled microbes?

Answer 15

Nose

Question 16

What is the primary defence in the nose?

Answer 16

Mucociliary clearance = motile cilia

Question 17

What are the secondary defences in the nose?

Answer 17

Secretion of antimicrobial peptides and reactive oxygen species

Question 18

What are the two main microbiota in the nasal tract?

Answer 18

Firmicute = forms biofilms that coat the nasal lining 
Actinobacteria = promote release of fatty acids

Question 19

What are the natural host defences to pathogen entering through the nose?

Answer 19

Mucous

Cilia

Question 20

What are the natural host defences to pathogens entering through the mouth?

Answer 20

Saliva
pH
Change in temperature
Host immune system

Question 21

What are the predominant microbiota in the mouth?

Answer 21

Fimicutes
Bacteroidetes
Proteobacteria

Question 22

What do the microbiota found in the mouth form which acts as a barrier to pathogenic organisms?

Answer 22

Elaborate microbial scaffold

Question 23

What are the natural host defences to pathogens on the skin?

Answer 23

Sweat = acidic

Antimicrobial properties

Question 24

What are the predominant microbiota found on the skin?

Answer 24

Firmicutes

Actinobacteria

Question 25

What are the natural host defences to pathogens in the intestine?

Answer 25

Low pH
Bile
Immune system
Mucus

Question 26

What are the predominant microbiota found in the intestine?

Answer 26

Bacteroidetes

Firmicutes

Question 27

How does an individuals microbial composition vary?

Answer 27

With age, exposure and location along the GI tract

Question 28

Why are urinary systems almost sterile?

Answer 28

Urine helps flush away any microbes that start to colonise

Question 29

What is the predominant microbiota in the urogenital tract?

Answer 29

Firmicutes

Question 30

What diseases may be impacted by changes in our microbiota?

Answer 30

IBD
Pre-term birth
Cardiovascular disease
Obesity

Question 31

The proportion of what microbe decreases as we get older?

Answer 31

Bifidobacterium = actinobacteria

Question 32

The proportion of what microbe increases as we get older?

Answer 32

Proteobacteria