24. Microbiota

Question 1

3 main functions of microbiota?

Answer 1

Metabolic- synthesize vit K, folic acid, digest complex carbs

Protective - eliminate pathogens, tolerate commensals

Trophic - control epithelial cell proliferation/differentiation

Question 2

2 methods of metagenome sequencing?

Answer 2

Targeted sequencing of phylogenetically informative genes (16S rRNA)

Random sequencing of all genes in microbial community

Question 3

Adult guy microbiota is dominated by what 2 types of bacteria?

Answer 3

Firmicutes, Bacteroidetes

Question 4

_________ studies suggest all healthy adults share most of the same bacterial species

Answer 4

Culture-based

Question 5

______________________ studies show that vast microbial diversity is highly variable over time and across populations

Answer 5

Culture-independent sequencing

Question 6

Human Microbiome Project focused on producing what?

Answer 6

Reference genomes

Question 7

Purpose of Integrative Human Microbiome Project (iHMP)?

Answer 7

Data on healthy vs unhealthy microbiota

Role in pre-term birth, IBS, diabetes

Question 8

2 major routes microbiota affects metabolic diseases?

Answer 8

• Innate immune response: structural components of bact (LPS) => inflammation
• Bacterial metabolites of dietary compounds: biological activities that regulate host functions (SCFAs from fiber)

Question 9

How are C.diff toxins toxic?

Answer 9

Disrupt tight juntions in epithelial of large intestine

Question 10

C.diff vegetative cells produce what 2 toxins that cause epithelial dmg?

Answer 10

TcdA, TcdB

Question 11

What 3 things can C.diff cause?

Answer 11

• Severe diarrhea
• Pseudomembranous colitis
• Toxic megacolon

Question 12

What induces C.diff spore germination

Answer 12

Intestinal components => bile acids

Question 13

Bacteria in gut are identified by analyzing what?

Answer 13

Feces