microbiota in homeostasis (W9)

Question 1

differences in microbiome in areas of body?

Answer 1

composed of very different types of bacteria - microbiome very different in areas of body

Question 2

microbiome development at birth?

Answer 2

different bacteria depending on birth (vaginal vs caesarean delivery)

Question 3

when is the microbiome mainly like an adults

Answer 3

toddler (1-3)

Question 4

breast milk bacteria actions?

Answer 4

releases short chain fatty acids providing energy for intestinal cells
promotes production of anti-inflammatory molecules
produces sialic acid for brain development

Question 5

what is the adult microbiome shared with (examples)

Answer 5

household, environment, food, pets

Question 6

what is the adult microbiome altered by and what happens to it when you age?

Answer 6

altered by antibiotics
less variety when aged

Question 7

SCFA?

Answer 7

type of short chain fatty acids

Question 8

properties of SFCAs

Answer 8

anti-inflammatory and anti-tumour properties
stimulate production of protein YY

Question 9

functions of the microbiome?

Answer 9

energy biosynthesis
protection from pathogenic bacteria
immune system education
vitamin production
host cell proliferation
brain function
bile salt metabolism
drug metabolism and activity

Question 10

microbiomes protection from pathogenic bacteria?

Answer 10

physically blocks other bacteria entering
lowers pH below optimal growth conditions
produces bacteriocins (kills e.g. salmonella)

Question 11

connections between gut and brain?

Answer 11

links between GI and brain function with depression, anxiety, GI symptoms, IBS
potentially involved in CNS disorders

Question 12

what can bacteria in the gut stimulate production of

Answer 12

stimulates 5-HT production

Question 13

what do secondary bile acids do and what produces them?

Answer 13

activate cells in liver, intestine, inflammatory cells
regulate bile acids synthesis
reduce gut inflammation
activate vitamin D receptors
stimulate peptide-1 (like glucagon)

produced by microbiome

Question 14

microbiome and obesity?

Answer 14

mouse experiment - twins gave microbiota transplant, obese twin -> obese mouse, lean twin -> lean mouse

Question 15

Bacteroidetes and weight loss?

Answer 15

increased Bacteroidetes associated with weight loss

Question 16

IBD main variants?

Answer 16

ulcerative colitis (colon)
Crohn’s disease (affect any part of gut)

Question 17

IBD treatment

Answer 17

anti-inflammatory treatment
surgery

Question 18

IBD presentation?

Answer 18

abdominal pain
diarrhoea
weight loss

Question 19

IBD and microbiome?

Answer 19

IBD causes reduced diversity of microbiome
some bacteria increased, some decreased

Question 20

microbiome and colon cancer?

Answer 20

some bacterial species consistently elevated
large number of bacteria reduced

Question 21

most common bacterial infection in humans? what can happen?

Answer 21

helicobacter pylori
disrupt gastric mucus layer
promotes inflammatory immune response
cause chronic gastritis (can lead to peptic ulceration)
increases risk of stomach cancer

Question 22

what are peptic ulcers symptoms

Answer 22

usually asymptomatic
can cause bleeding leading to anaemia
upper abdominal pain, indigestion, heartburn

Question 23

peptic ulcer symptoms investigation

Answer 23

urea breath test
stool antigen test
endoscopy, biopsy

Question 24

what causes antibiotic associated colitis?

Answer 24

clostridioides difficile infection

Question 25

what does clostridioides difficile infection cause

Answer 25

antibiotic associated colitis

Question 26

prevention and treatment of clostridioides difficile infection

Answer 26

antibiotics stewardship (more likely to cause this infection) - measure and improve use of antibiotics
infection control measure
antibiotic treatment - vancomycin or metronidazole

Question 27

faecal microbiota transplantation?

Answer 27

healthy microbiome given to patient with recurrent disease
(more effective than vancomycin)