Gut microbiota

Question 1

what are the symptoms of gastroenteritis

Answer 1

nausea
vomiting
diarrhoea
abdo discomfort

Question 2

what is enterocolitis

Answer 2

Inflammation involving the mucosa of both small and large intestine.

Question 3

what is diarrhoea

Answer 3

• Abnormal faecal discharge characterised by frequent and/or fluid stool.
• Result of disease in small intestine
• Involves increased fluid and electrolyte loss

Question 4

what is dysentry

Answer 4

• Inflammation disorder of the GI tract
• Usually resulting from disease of the large intestine.
• Often associated with blood and pus in the faeces
• Often accompanied by pain, fever & abdominal cramps

Question 5

what are the signs and symptoms of GI infection

Answer 5

• Diarrhoea / dysentery
• Malaena
• Blood in faeces
• Pus in faeces
• Abdominal cramps
• Fever
• Sepsis

Question 6

what pathogens in food commonly cause GI infection

Answer 6

• Escherichia coli
• Salmonellasp.
• Campylobactersp.
• Listeriasp.
• Clostridium perfringens
• Bacillus cereus
• Yersinia enterocolitica
• tapeworm

Question 7

what pathogens in water commonly cause GI infection

Answer 7

• Escherichia coli
• Salmonellasp.
• Campylobactersp.
• Shigellasp.
• Vibrio cholerae
• rotavirus

Question 8

what pathogens from animals commonly cause GI infection

Answer 8

• Escherichia coli
• Salmonellasp.
• Campylobactersp.
• Clostridium perfringens
• Yersinia enterocolitica

Question 9

what are some common toxin producing pathogens

Answer 9

–Bacillus cereus
–Clostridium botulinum
–Clostridium perfringens
–Escherichia coli (enterotoxigenic –ETEC)
–Vibriocholerae

Question 10

what host defences are present in the mouth

Answer 10

• Flow of liquids
• Saliva
• Antimicrobials
• Normal microbiota

Question 11

what host defences are present in the stomach

Answer 11

• Acid pH
• Antimicrobials
• Mucus

Question 12

what host defences are present in the small intestine

Answer 12

• Flow of gut contents
• Peristalsis
• Mucus
• Bile
• Secretory IgA
• Antimicrobial peptides
• Normal bacterial microbiota

Question 13

what host defences are present in the large intestine

Answer 13

• Normal microbiota
• Peristalsis
• Mucus
• Shedding and replication of epithelium

Question 14

what bacteria are commonly found in probiotics

Answer 14

• Lactobacillus spp.
• Bifidobacteriumspp.
• Bacteroidesspp.

Question 15

what are pre biotics

Answer 15

non digestible food ingredient which stimulate growth of gut microbiota

Question 16

how are good bacteria helpful

Answer 16

develops a mucosal barrier
activates/ train the immune system 
reduces pH in large bowel
produces short chain fatty acids
metabolism of bile acids 
vitamin synthesis 
Prevent colonisation by pathogens
Excrete useful metabolites
Ferment unused energy substrates
Produce hormones

Question 17

what factors influence gut microbiota

Answer 17

• Physiological status
• Underlying disease
• Intestinal secretions
• Intestinal motility
• Immune mechanisms
• Environmentalfactors
• Use of antibiotics

Question 18

what are PAMPs / MAMPs

Answer 18

pathogen / microbe associated molecular patterns:

TLRs
NODs
NLRs

Question 19

how can infections occur

Answer 19

usually faecal oral route
maybe when commensals become pathogenic 
•Ingestion of infected food and water
•Ingestion of bacterial toxins
•Use of oral antibiotics

Question 20

what commensal might be found in the stomach

Answer 20

lactobacilli

Question 21

what commensals are commonly found in the large bowel

Answer 21

bacteriodes
fusobacterium
strep faecilis
e. coli 
lactobacilus
staph aureus
clostridium
psuedomonas

Question 22

what antibody is secreted in the small intestine

Answer 22

IgA

Question 23

describe the host defences of the GI systm

Answer 23

saliva 
peristalsis 
flow of liquids
antimicrobials
normal microbiota
pH
mucus
bile
IgA
shedding of epithelia

Question 24

what bacteria are normally found in the small bowel

Answer 24

lactobaccili, streptococci
enterobacteriodes
bacteroids