lecture 20 - gut microbiome Flashcards
What is the relationship between pH of the GI tract and the diversity of the microbiome?
proportiona relationship - stomach has much less diversity than the large bowel for example
What are some of the functions of the gut microbiome?
Immune function support, colonisation resistance, bilirubin excretion, vitamin synthesis
What is the term for changes in the gut microbiome that are associated with disease?
Dysbiosis
What is necrotising enterocolitis?
A condition where normal microbiota are translocated into the gut wall, causing it to become leaky and necrotic
What is the pattern of types of bacterial infection in a polymicrobial gut infection?
Facultative anaerobes, e.g. E. coli use up available oxygen, and then provide an environment for obligate anaerobes to thrive
Which patients are at risk of necrotising enterocolitis?
Low birth weight/premature/formula fed infants
What is the shape of Helicobacter pylori?
Spiral rod (gram-negative)
What feature gives Helicobacter pylori motility?
Flagella
What virulence factor allows Helicobacter pylori to survive in stomach acid?
Produces urease which makes ammonia to lower pH
What is caused by chronic infection with Helicobacter pylori?
Gastritis, which can lead to peptic and/or duodenal ulcers (peptic ulcer disease)
What is atrophic gastritis?
Gastritis where glands in the stomach are destroyed, reducing acid and pepsin production
What type of chronic inflammatory gastritis casued by Helicobacter pylori is most likely to lead to adenocarcinoma?
Atrophic gastritis - where glands are destroyed
What is the key non-invasive diagnostic technique for diagnosis of Helicobacter pylori infection?
Urea breath test
What is the Urea breath test?
Test to diagnose infection with Helicobacter pylori. Measures CO2 in the breath, which is produced when Helicobacter pylori converts urea to CO2 with urease enzymes
How is Helicobacter pylori infection treated?
Proton pump inhibitor, antibiotics
