Week 2 Lecture Flashcards

What is commensal bacteria?

It is bacteria that lives on/inside of the human body but usually doesn’t cause harm.

How is the microbiome different around the human body?

The phyla/genus/species of the bacteria differ by location on the body and also between individuals (different phyla of bacteria) - this basically means that we do not have an identical microbiome.

What are some of the roles of the commensal bacteria?

Immune system development, protection against pathogens, the production of vitamins, initiation of angiogenesis in the intestine, short chain fatty acid production through fermentation, promotion of fat storage and modulation of the central nervous system.

How does the microbiome contribute to the protection against pathogens?

They can prevent the colonisation of pathogens, can stimulate the immune system, metabolism of antimicrobial drugs, metabolise xenobiotic substances.

What are examples of direct transmission?

Direct contact (kissing and touching), droplet spread, vertical spread and vectors.

What are examples of indirect transmission?

Fomites, airborne droplets and food/water borne.

In what situations can commensal bacteria cause infection?

If they spread into sterile areas of the body or if they increase in number.

What is a common reason for the development of C. diff?

Antibiotics eliminate a lot of the commensal bacteria in the gut lumen and therefore reduces antimicrobial defences.

What type of bacteria is C. diff?

Gram positive, anaerobic, spore former.

How is C. diff spread?

Faecal-oral root.

What symptom can C. diff be responsible for when using antibiotics?

Antibiotic associated diarrhoes - pseudomembranous colitis.

What is FMT?

Faecal microbial transplant - transfer of the bacterial microbiome of a healthy donor to the intestines of another patient in order to try and restore the healthy balance of bacteria in the gut.

What is a supplement to Koch’s postulates?

That human disease can be described by a disturbed microbial community structure.

What does dysbiosis mean?

Imbalance of the normal microbiome - changes qualitatively/quantitatively, metabolism and distribution - this can be harmful to a patient.

How was it discovered that longevity and health could be improved in relation to the microbiome?

Replacement of native florae with host-friendly florae was beneficial - manipulation of the intestinal florae with friendly bacteria that was found in yoghurt.

How can the microbiome influence non-infectious disease?

It can have relation to many human traits, behaviour and disease.

What are the modifiable and the non-modifiable factors that changes the microbiome over time?

Modifiable - lifestyle and diet.

Non-modifiabe - age and immune status.

What are prebiotics?

They are non-digestible food products that can benefit a host by selectively stimulating the growth or activity of bacteria in the gut to improve health.

What are probiotics?

They are living but non-pathogenic organisms that are used as food ingredients to benefit the host.

What is the purpose of microbiome research in non-infectious disease?

To determine which diseases are impacted by the microbiome to identify ways in which to apply this knowledge to improve health care. It can distinguish between bacterial and viral contributions.

What is pharmacomicrobiomics?

It is an emerging field that describes the interaction of drugs with the microbiome,