Gut Microbiota and Immunity

Question 1

Human microbiome

Answer 1

the combined genetic matter of the micro-organisms residing on the human body

Question 2

Microbiota

Answer 2

the micro-organisms which reside in a particular community e.g. gut microbiota, skin microbiota

Question 3

what aspects of the mouth protect the body

Answer 3

saliva
antimicrobials like IgA
the microbiota

Question 4

what aspects of the oesophagus protect the body

Answer 4

flow of liquids

peristalsis

Question 5

bugs that can survive in the stomach

Answer 5

helibacter pylori

Question 6

what aspects of the small intestine protect the body

Answer 6

flow of contents
peristalsis
mucus
secretory IgA - important as can pass through mucal membranes
antimicrobial peptides - A and D defensins
Microbiota

Question 7

what aspects of the stomach protect the body

Answer 7

pH - very acidic environment

antimicrobials - defensins (peptides that can kill bacteria and viruses through a variety of mechanisms) beta defenssins

Question 8

what cells in the stomach produce acid

Answer 8

the parietal cells

Question 9

SIBO

Answer 9

Overgrowth of bacteria in the intestine
diarrhoea, malabsorption
could be implicated by PPIs and Opioids
associated with IBS

Question 10

what aspects of the large intestine protect the body

Answer 10

• peristalsis
• mucus
• shedding and replication of epithelium
• microbiota

Question 11

E.Histolytica

Answer 11

adheres to epithelial layer of the gut wall

• often infected individuals are asymptomatic, thought to cause disease in 10% of cases
• part of it mechanism for doing this is secreting an enzyme which cleaves mucin, the main component of the mucus layer

Question 12

the three friendly bacterias of the gut

Answer 12

• lactobacillus
• bifidobacterium
• bacteroides
  they produce bacteriocins

Question 13

why is the gut microbiota important

Answer 13

1) Prevent colonisation by pathogens (produce bacterocins, acid producing, occupy space / metabolites (competition))
2) Ferment unused energy substrates (esp fibre) and mucus to produce useful metabolites (SCFA) beneficial for health (e.g. butyrate)
3) Synthesise and excrete vitamins
4) Influence release of gut hormones influencing digestion / metabolism of food and appetite
5) Interact with the immune system

Question 14

what can be the cause of a lower bacterial diversity

Answer 14

• IBD
• Atopic Eczema
• Obesity
• coeliac disease

Question 15

what factors influence the microbiome

Answer 15

• inherited
• food + probiotics, artificial sweeteners
• envuriment
• antibiotics
• drugs (proton pump inhibitors)

Question 16

what are some ways to promote positive microflora

Answer 16

• fibre

- pre biotics e.g. fermented foods, leeks, onions

Question 17

how are infections acquired into the GI contract

Answer 17

• faecal-oral route, mostly through indigestion of bacterial toxins and through ingestion of infected food and water

Question 18

gastroenteritis

Answer 18

can cause nausea, vomiting, diarrhoea and abdominal pain

Question 19

dysentry

Answer 19

infection within the intestinal tract causing diarrhoea and cramps

Question 20

enterocolitis

Answer 20

inflammation of the small and large intestine