Lecture 14 Flashcards
(31 cards)
gut microbiome represents the…
greatest density/diversity of microbes in the body
roughly half of faeces produced is
microbes
probiotics=
live microorganisms that confer a health benefit on the host
2 examples of probiotics
Bifidobacterium and Lactobacillus
prebiotics=
selectively fermented ingredient that results in specific changes in the composition and/or activity of the GI microbiota
example of a pathobiont
C. difficile
intestines contain more _ than any other organ
immune cells
in GI tract; single layer of cells separates the _ from the _
luminal contents from the host
4 layers of the gut wall:
- mucosa
- submucosa
- muscularis
- serosa
the inner most layer of gut wall=
mucosa- single layer of columnar epithelium
mucosa has _ which increases the SA
villi
what layer of the wall is connective tissue
submucosa
what layer of the gut wall is thick muscle
muscularis- 2 layers: circular and longitudinal
which layer of the gut wall secretes lubricating fluids
serosa
villi in the small intestine increase _ and _ capacity
absorptive and digestive capacity
epithelial cells can emerge from _ within _ and migrate up towards surface
stem cells
within crypts
Paneth cells secrete
antimicrobial peptides
more goblet cells and less epithelial cells as you move down the GI tract=
deeper mucous barrier ‘glycocalyx’
the highest level of SCFAs are found in the
proximal colon- used locally by enterocytes or transported across gut epithelium into bloodstream
2 major SCFA signalling mechanisms=
- inhibition of histone deacetylases
- activation of G-protein coupled receptors
buffered stool example:
OMNI gene gut- very commonly used
- stable at room temp >60 days
- cannot be used for functional assay later
stool may not be reflective of…
mucosa-associated microbes and proximal luminal contents
in brush sampling you…
pass sampling device into rectum and brush mucosal wall
- invasive/expensive
fermentation of fibre supports the growth of microbes that produce…
the metabolites SCFAs
