Probiotics and prebiotics Flashcards
Prebiotics
Substrate selectively utilized by host microbes conferring a health benefit (changing definition)
Synbiotic
Probiotics + Prebiotics
Prebiotic original (1995)
Non-digestible food ingredient that benefits the host by stimulating the growth/activity of one or limited number of bacteria in the colon to improve hosts health (bacteria can digest)
2015 prebiotic definiton
Selectively fermented ingredient that allows specific changes in composition/activity in GI microbiota that confers a benefit upon host well being and health (more inclusive)
Non-digestable carbs are probiotics if…
1) Resistance to gastric acidity + mammalian enzymes
2) Susceptible to fermentation by gut bacteria
3) Improve viability or activity of beneficial microbes
Most common Prebiotics
Inulin, GOS, FOS
Route of prebiotics
Selective fermentation by Bifidobacterium –> secrete SCFAs (Lactate, acetate, propionate, butyrate) –> stimulate host cells
Sources of Prebiotics
Lactose, starch, fruits, veggies, honey, seeds, beans, mustard…
From starch
Maltooligosaccharides (MOS)
From Lactose (milk)
Lactulose
Industrial probiotics
Lactulose, FOS…
Prebiotic Selection Criteria (additions)
- Selective stimulation of growth of probiotics
- Beneficial to host
- Stable in food and processing conditions
Special strains of Bifido grow on
Oligofructose (competitive advantage)
Confirmation of selectivity of prebiotic
Monitor changes in fecal microbiota and decreasing prebiotic concentrations in vitro and in vivo
Mechanism of action of prebiotics difficult to discriminate because…
Due to prebiotic only or changes in microbiota
Prebiotics for CD and UC infections
Varying results
CD + Prebiotics
FOS has shown to increase bifido and decrease disease but not lactulose
UC + Prebiotics
FOS + inulin and shown to reduce calprotectin and improve symptoms but not lactulose
Has shown no effect
Lactulose
Calprotectin
Marker of inflammation
Prebiotics mechanism (5)
1) Hepatic lipogenic enzyme regulation
2) Module histone acetylation so more genes are expressed
3) Modulate mucin production
4) Increased lymphocytes and leukocytes in GALT and peripheral blood to increase IR
5) Increase macrophages phagocytic funtion
Hepatic lipogenic enzyme regulation
Increases in SCFA production (Propionic acid)
Histone acetylation
SCFAs (butyric acid)
Increase WBCs from prebiotics with
FOS (+)
How to increase phagocytic function of intra-inflammatory macrophages
Increase GALT IgA secretion
Prebiotics as food because
Good sensory features _ well balanced nutrition composition
Prebiotics as food benefits
1) Freshness
2) Moisture
3) Fiber incorporation (liquids)
4) Gelling (low fat)
5) Replacement and emulsion (replace fat)
5) Dietary
Component
A substance that can be characterised chemically but is not a drug or organism; mostly food grade
FAO Prebiotic
nonviable food component that confers a health benefit on the host associated with modulation of the microbiota
Health benefit
Measurable and not due to adsorption into the bloodstream or due to component acting alone and over-riding adverse effects
Modulation
Sole presence of the component and its formulation changes composition or activity in the target host
Modulation examples
Fermentation, receptor blockage…
FAO
Food and Agriculture Organization of the United Nation
Steps to a prebiotic by FAO (7)
Component characterization –> Functional characterization –> Product formulation –> safety assessment –> DBRC studies –> preferable second DBRC studies –> Prebiotic classification
Component characterization (5)
Source, origin, purity, chemical composition, structure
Other type of component specification/product formulation
Vehicle, concentration, amount being delivered
Functional Characterization
In vitro and animal testing
Safety assessment includes
In vitro and animal studies + P1 trails if not GRAS or equivalent
RCT requires
Sample size and primary outcome appropriate to determine if efficacious
RTC outcomes should show (Functionality)
Minimal proof that there is a correlation between outcome and changes in microbiota at specific site
Functionality Sites
GI tract, UG tract, Skin…
Need to correlate
A specific function at a specific site with a physiological outcome in a specific timeframe
The ____ should change in a statistical way for prebiotic test
Target variable
Statistical way for
Target group in a biological way
Statistical significance can be due to
Small variability and not biological significance on disease
RCT for prebiotics should be tested against
Placebo or standard control substance
Physiological outcomes possible due to prebiotics (8)
Satiety (satisfied), Endocrine mechanisms, Nutrient adsorption, Decreased infection duration, fat decrease, bowel movement and regularity, Cancer risk markers, Changes in adaptive and innate immunity
Satiety
Toward carbs, fats, and total energy intake to prevent obesity
Endocrine mechanisms
Regulate food intake + energy usage in the body
Nutrient adsorption for prebiotics (4)
Calcium, Mg, trace elements, protein
Parameters that can be lowered by prebiotics
Blood lipids and endocrine (fat disease)
Safety recommendations for prebiotics
1) GRAS status or equal –> might not need additional toxicological studies
2) Safe levels with minimal symptoms and side effects
3) No contaminants or impurities
4) NO alteration that has long term detrimental effects on host
Safety parameters established by
All National Regulations
Production Management Issues
It is on the manufacturer to ensure purity and consistency between lots
Formulation and storage management issues
Recommended that stability limit, processing and production technology effect, and desired biology activity in target host evaluated
Regularity Management Issues
Regulatory agency where sales are to be made with documentation supporting health claims provided by the producer (FAO in US)
