DMH2- The gut microbiome

Question 1

Define Pathogen

Answer 1

Disease-causing microve not normally found in the gut

Question 2

Define commensal

Answer 2

No particular benefit or ill effect

Question 3

Define symbionts

Answer 3

Mutual benefit to host and bacteria

Question 4

Define pathobionts (opportunistic pathogens)

Answer 4

Normally commensal, but under certain conditoons can become invasive or cauase disease

Question 5

What happens to the anarobicity as you go down the GI tract?

Answer 5

Anaerobicity decreases as oxygen becomes less and less

Question 6

What happens to the pH of the stomach as you go down thew GI tract?

Answer 6

pH increases

Most acidic is the stomach where the pH is @

Small intestine the pH is between 4-5

Large intestine pH5

Question 7

What are some benefit of action that the human microbiome has

Answer 7

Some microbiome can help with food digestion i.e digestion of plant carbojhhdrates into short chain fatty acids

Responsible for 30% of small molecules in human plasma

synthesis of esssential vitamins necessary for enzyme, blood clotting andf production of nucleotides:

• Vit B7: coenzyme for carboylase enzyme
• Vit B5- necessary for CoA synthesis
• Vit B9- essential for the production of nucelotides
• Precursor to vit K: required for blood clotting

Metabolism of drugs and toxins
Compete with pathogens-supress their grwoth

Program the immune system

Question 8

Decribe how the mucous layer and immune system keeps us safe from microbial invasion/infection

Answer 8

GIT mucus layer helps prevent normal microbiota invading

Contains specialised cells ( Mcells: dendritic cells) which ingest bacteria by constanly sampling for bacteria and microbial antigens

They pass microbial antigens to B and T cells

Secretion of IgA antibodis

Nutralise bacteria and toxins to prevent infection

Question 9

What factors can effect what microbiome are found in our first months of life ?

Answer 9

Delievry of baby:
babies born via vaginal cavity have lactobacillus which id dominant in the vaginal cavity

Babies born via caesarian section have more skin microbiome such as staphlococcus

Child hood nutritian 
Antibiotic treatment 
Diet
Infections 
Pollutants

By age 3 the gut microbiome is similar to adults