solubility (CHO and digestion)
is CHO soluble in the aqueous environment of the digestive tract?
yes = soluble
no = insoluble
not determined by enzymes
digestibility (CHO and digestion)
does host organism have the enzymes necessary to digest CHO?
digestible CHO vs nondigestible CHO (fibre)
fermentalibity
do gut bacteria have the enzymes necessary to break down CHO?
yes = fermentable
no = non-fermentable
- Simple System w/o function caecum
e.g. human, cat, dog
key features:
- monogastric
- non-functional caecum
- suited for nutrient-dense, low fibre diet
How does digestion work?
Oral cavity, stomach, small intestine, large intestine
oral cavity
food chewed and mixed with saliva
enzymes released - α-amylase and lingual lipase
stomach
food become chyme
gastric emptying - 2-6 hours
gastric glands secrete gastric juice: H2O, electrolytes, HCl, enzymes
small intestine (duodenum, jejunum, ilium)
main site for nutrient digestion and absorption
large surface area:
1. Keckring folds
2. Villi
3. Microvilli
chyme acidity neutralized by pancreatic juice
food digested by pamcreatic juice and bile acids
large intestine (aka colon)
- site of fermentation
- producion of SCFA
- has the highest concentration of gut bacteria
- site for water absorption
Gut bacteria
important for fermentation of non-digestible CHO
CHO fermentation produces many compounds, eg. SCFA
- Simple System w/ function caecum
e.g. horse, rabbit, hamster
key features:
- monogastric
- ‘pseudo-ruminant’
- hundgut fermenter (after small intestine)
- functional caecum: adapted for diets consisting of large amounts of fodder and foraging (grass, hay, etc)
- all other regions of gut function similar to monogastric system
