Fibre Flashcards
what is fibre
indigestible part of plants
where is it fermented
in the large intestine where it provides food for bacteria in the form of short chain fatty acids
Give examples of resistant starches
legumes, cooked and cooled peeled potato, unripe banana cooked and cooled rice
what is soluble fibre
Fibre that dissolves in water to form a gel.
function of soluble fibre
lowers blood cholesterol by binding with bile. Slows the passage of stool and ferments in colon to produce short chain fatty acids to feed microbiome
where is resistant starch digested
Large bowel
what is Butyrate
Waste from starch eating microbiome - an energy source for the body . Absorbed by large intestine
Describe insoluble fibre
Does not dissolve in water .
Non starch polysaccharides
Does not form gels
found in whole grains an veg, Cellulose
Acts a s a hydrophilic bulking agent for stools
speeds passage of stools through gut
name 2 forms of insoluble fibre
Ligin (not fermented) - linseed, bran, brown rice nuts and seeds
Hemi cellulose - corn, bran psyllium
signs of fibre deficiency
constipation
hiatus hernia, IBS, diverticular disease haemorrhoids
infrequent bowel movements
pain, straining, gas, bloating cramping
diarrhoea
Bowel cancer, Gall stones, Dental caries obesity , Circulatory disorders due to increased cholesterol
3 criteria to be a prebiotic
Resistant to digestion by humans
provides substrate for fermentation by microbes
Selectively promotes health of beneficial microbes
List forms of soluble firbre
Betaglucans - oats and barley
gums and mucilages - Psyllium
pectins - fruit and veg
overall function of fibre
1 facilitation of faecal elimination by absorbing water in colon
2. Protection of bowel lining - faecal material contains toxins, lithocholate, dexhcholate (byproducts from bile) - Fibre binds with the to decrease contact time
3. prebiotic activity - soluble fibre & oligosaccharides are fermentable food for probiotic bacteria - they ferment fibre for energy.
4. Increased Cholesterol extraction - bile acids made from cholesterol in liver(major removal of cholesterol )
95% bile acids entering duodenum are reabsorbed back into blood stream
Can decrease serum cholesterol and LDL
5. Anti inflammatory - lowers CRP
6. Anti obesity - assists with weight gain by providing build in digestive tract and slowing digestion
6. Increases Glycemic control - fibre slows down nutrient digestion /absorption, and can lower GI of food , inhibit insulin release and stabilise BSL - decreasing Type 2 diabetes
what vitamin can be syntesised by microbiome in gut `
Vit K, and Some Bit B’s.
