Microbiota Immune Response Flashcards
What do commensal gut bacteria contribute to good health?
- provide energy by metabolizing dietary polysaccharides
- provide vitamins
- required for development of immune system
- protect from pathogenic bacteria
With a germ free gut do B-cell follicles develop normally?
no
Commensal microbiota balance pro and anti-inflammatory immune cells, how do they do this?
some bacteria promote TH cells
other promote Tregs
What dysbiosis favors what type of response?
Th17 and Th1 over anti-inflammatory Treg (state)
IBD (crohn’s disease and ulcerative colitis) cause what type of immune response? What is likely to be a cause of IBD? What is thought to be the initiating factor
T-cell mediated inflammatory response due to stimulation by microbial agents
- likely due to changes in development or composition of intestinal microbiota (dysbiosis)
- commensal bacteria thought to be initiating factor
Can you transfer IBD through a fecal transplant?
yes
How can you protect/treat IBD?
give bacteria that induces tregs cells preventing IBD
The decline of infectious diseases correlates with the rise in?
immune disorders
Bacteria and viruses elicit Th1 responses IL2 and INF gamma, what does this response down regulate and how does this affect allergy?
down regulate Th2 responses which produces IgE (allergy)
Does high fat diet induce changes in the microbiota?
yes, it can promote obesity
What happens if fecal matter from an obese person is transferred into a mouse?
obese mouse
-even with low fat-high fiber diet
-lean wins out
What are causes of microbio dysbiosis?
antibiotics
diet, especially high-fat diet
early childhood experience
model of delivery: vaginal vs. cesarean
Do antibiotics impair cancer therapy?
yes
Dysbiosis of the gut commensals likely contributes to what 4 things?
- chronic inflammatory diseases IBD
- autoimmunity
- allergy
- obesity
What can dysbiosis be caused by?
- diet
- antibiotics
- stress
- possible early childhood exposure to commensals
