GI 6

Question 1

What is the gut microbiome?

Answer 1

A collection of microorganisms in the gut including bacteria, viruses, fungi, archaea, and eukaryotes.

Question 2

What are the key functions of the gut microbiome?

Answer 2

Protection from pathogens, intestinal integrity, energy harvesting, immune regulation, vitamin synthesis, and tissue/immune development.

Question 3

How is the gut microbiome studied?

Answer 3

Using 16S rRNA gene sequencing, Next Generation Sequencing (NGS), metagenomics, and bioinformatics.

Question 4

What are the main phyla in the gut microbiome?

Answer 4

Firmicutes, Actinobacteria, Bacteroidetes, and Proteobacteria.

Question 5

How does the gut microbiome develop from birth?

Answer 5

Initial colonization depends on delivery mode; stabilizes to adult-like profile by ~2.5 years.

Question 6

How does diet affect the microbiome?

Answer 6

High fiber diets increase Bacteroidetes and SCFA production, while high fat/protein diets increase Firmicutes.

Question 7

What are short-chain fatty acids (SCFAs)?

Answer 7

Metabolites like acetate, propionate, and butyrate that regulate gut health and immune function.

Question 8

What diseases are associated with dysbiosis?

Answer 8

Obesity, IBD, autism, anxiety, and others.

Question 9

What is faecal microbiota transplantation (FMT)?

Answer 9

Transfer of stool from healthy donor to restore microbial balance, used especially for C. difficile infections.

Question 10

What are probiotics?

Answer 10

Live microorganisms that provide health benefits when consumed in adequate amounts.

Question 11

What are common genera of probiotics?

Answer 11

Lactobacillus, Bifidobacterium, E. coli Nissle 1917, Saccharomyces boulardii.

Question 12

How do probiotics work?

Answer 12

Through gut colonization, immune modulation, gene regulation, antimicrobial activity, and enhancing barrier integrity.

Question 13

What are limitations of probiotics?

Answer 13

Strain-specific effects, inconsistent evidence, poor colonization, not FDA/EFSA approved.

Question 14

What are microbiota-accessible carbohydrates (MACs)?

Answer 14

Carbohydrates in dietary fiber that are a major fuel source for colonic bacteria.

Question 15

How do probiotics affect the immune system?

Answer 15

They alter cytokine expression including IL-6, IL-8, TNF-α, and IFN-γ.