Gut microbiota Flashcards
what are the symptoms of gastroenteritis
nausea
vomiting
diarrhoea
abdo discomfort
what is enterocolitis
Inflammation involving the mucosa of both small and large intestine.
what is diarrhoea
- Abnormal faecal discharge characterised by frequent and/or fluid stool.
- Result of disease in small intestine
- Involves increased fluid and electrolyte loss
what is dysentry
- 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
what are the signs and symptoms of GI infection
- Diarrhoea / dysentery
- Malaena
- Blood in faeces
- Pus in faeces
- Abdominal cramps
- Fever
- Sepsis
what pathogens in food commonly cause GI infection
- Escherichia coli
- Salmonellasp.
- Campylobactersp.
- Listeriasp.
- Clostridium perfringens
- Bacillus cereus
- Yersinia enterocolitica
- tapeworm
what pathogens in water commonly cause GI infection
- Escherichia coli
- Salmonellasp.
- Campylobactersp.
- Shigellasp.
- Vibrio cholerae
- rotavirus
what pathogens from animals commonly cause GI infection
- Escherichia coli
- Salmonellasp.
- Campylobactersp.
- Clostridium perfringens
- Yersinia enterocolitica
what are some common toxin producing pathogens
–Bacillus cereus –Clostridium botulinum –Clostridium perfringens –Escherichia coli (enterotoxigenic –ETEC) –Vibriocholerae
what host defences are present in the mouth
- Flow of liquids
- Saliva
- Antimicrobials
- Normal microbiota
what host defences are present in the stomach
- Acid pH
- Antimicrobials
- Mucus
what host defences are present in the small intestine
- Flow of gut contents
- Peristalsis
- Mucus
- Bile
- Secretory IgA
- Antimicrobial peptides
- Normal bacterial microbiota
what host defences are present in the large intestine
- Normal microbiota
- Peristalsis
- Mucus
- Shedding and replication of epithelium
what bacteria are commonly found in probiotics
- Lactobacillus spp.
- Bifidobacteriumspp.
- Bacteroidesspp.
what are pre biotics
non digestible food ingredient which stimulate growth of gut microbiota
how are good bacteria helpful
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
what factors influence gut microbiota
- Physiological status
- Underlying disease
- Intestinal secretions
- Intestinal motility
- Immune mechanisms
- Environmentalfactors
- Use of antibiotics
what are PAMPs / MAMPs
pathogen / microbe associated molecular patterns:
TLRs
NODs
NLRs
how can infections occur
usually faecal oral route maybe when commensals become pathogenic •Ingestion of infected food and water •Ingestion of bacterial toxins •Use of oral antibiotics
what commensal might be found in the stomach
lactobacilli
what commensals are commonly found in the large bowel
bacteriodes fusobacterium strep faecilis e. coli lactobacilus staph aureus clostridium psuedomonas
what antibody is secreted in the small intestine
IgA
describe the host defences of the GI systm
saliva peristalsis flow of liquids antimicrobials normal microbiota pH mucus bile IgA shedding of epithelia
what bacteria are normally found in the small bowel
lactobaccili, streptococci
enterobacteriodes
bacteroids
