Microbiome

Question 1

Where are microbes typically found?

Answer 1

On body surfaces (outer and inner)

Question 2

Internal regions are typically ___?

Answer 2

Sterile

Question 3

Where do we all begin life?

Answer 3

In a sterile womb environment

Question 4

How does the colonization of bacteria occur?

Answer 4

In the birth canal
From mom’s skin
Breast milk

Question 5

When does colonization begin?

Answer 5

At birth

Question 6

What is in breast milk?

Answer 6

600 species of bacteria
Prebiotics which contain growth factors and food for bacteria

Question 7

What is found in the birth canal?

Answer 7

Skin bacteria that only colonizes during the 3rd semester of pregnancy

Question 8

What causes differences in gut microbiomes in babies?

Answer 8

Diet and delivery

Question 9

What do formula-fed babies have an increased frequency of?

Answer 9

Firmicutes

Question 10

What are the differences in microbiomes in Western countries?

Answer 10

Fewer E. coli
More lactococcus and lactobacillus

Question 11

What is competitive exclusion?

Answer 11

Normal flora produce inhibitor compounds to decrease pathogen growth

Question 12

Why is a healthy microbiome full?

Answer 12

There is no vacancy
Disruption of microbial barriers increase the chance of invasion by pathogens

Question 13

What do breast fed babies have?

Answer 13

Fewer bad bacteria even after weaning

Question 14

What is ETBF excluded by?

Answer 14

NTBF = commensal bacteria in the gut

Question 15

What is ETBF associated with?

Answer 15

Colitis

Question 16

How does NTBF kill ETBF?

Answer 16

Produces a perforin-like protein by T6SS which is a TLR2 agonist and will also enhance the target immune response

Question 17

What 3 toxins does C. diff produce?

Answer 17

TcdA, TcdB = glucosyl-transferases which inactive G-protein signals
CDT = binary toxin that acts as ADP-ribosomal transferase

Question 18

What does TcdA/B do?

Answer 18

Disrupts epithelial attachment

Question 19

What does binary toxin do?

Answer 19

Modifies actin cytoskeleton to facilitate bacterial adhesion

Question 20

What is the treatment for C. diff?

Answer 20

Fecal transplant = 85% cure rate

Question 21

How are gut genes turned on?

Answer 21

by bacterial growth factors

Question 22

What vitamins does bacteria produce?

Answer 22

Vit K = E. coli
90% of serotonin is bacterially produced

Question 23

How do bacteria aid in digestion?

Answer 23

Vast majority of digestive enzymes needed are bacterially produced
Helps digest fibers and lactose

Question 24

How do bacteria modulate the immune system?

Answer 24

Trains the immune system to distinguish between flora and pathogens