1. Lecture 4b- 31 January 2019
Fibre metabolism and regulation
Most of this lecture derived from Chapter 4 of Gropper

2. Outline of lectures 4a,b
Definition of Dietary Fibre
Plants and Fibre
Dietary Fibre

3. Outline of lectures 4a,b
Some Properties-dictate physiological and metabolic effects of fibre
            a) Water Solubility
            b) Water Holding/Hydration Capacity as well as viscosity
                     Slowed Gastric emptying
Reduced mixing of gastrointestinal contents with digestive enzymes
                     Reduced enzyme function
                     Decreased nutrient diffusion rate
                     Altered small intestine transit time

4. Outline of lectures 4a,b
Some Properties-dictate physiological and metabolic effects of fibre
c) Absorption or Binding Ability
                    Diminished absorption of lipids
                    Increased faecal bile excretion
                    Lowered serum cholesterol
                    Altered mineral balance

5. Outline of lectures 4a,b
Some Properties-dictate physiological and metabolic effects of fibre
d) Degradability or fermentability
             Fermentable fibres
                   Increased water and sodium absorption in colon
                   Mucosal cell proliferation
                   Provision of energy
                   Acidification of luminal environment
              Non-fermentable fibres
                   Detoxification
                   Increased faecal bulk

6. Outline of lectures 4a,4b
Recommended Intake of Fibre
            Implications in Disease Prevention and Management
Fibre-Based Herbal Medicines

7. Outline of lectures 4a,b
Summary

8. More Detailed Information Dietary Fibre
Recommended Intake of Fibre/Implications in Disease Prevention and Management
                        grams per day-DRI-40 tops,
50 obstruction
soluble fibre- hypocholesterolemic
-hypoglycemic
insoluble fibre- laxative
                               
                      
            

9. Dietary Fibre How is fibre metabolism regulated in humans?
-regulation of bacterial enzymes and pathways since
we cannot use our own enzymes to digest.
                               
                      
            

10. Fibre-Based Herbal Medicines Echinacea -few controlled studies
     -immune response boost-prevention or treatment of cold, flu or other infections
active agents
-hmw polysaccharides among others
-side effects-allergic reactions may occur
-use in systemic or immune system dysfunction is contraindicated
                               
                      
            

11. Fibre-Based Herbal Medicines Ginseng -cancer prevention
-fatigue reduction
-few controlled studies
-active agents-saponin glycosides and ginsenosides-
modulate hormones and central nervous system
function
-side effects-negative interactions with warfarin
                               
                      
            

12. -free radical scavenger
Fibre-Based Herbal Medicines
Ginkgo biloba
                -vascular flow
                -free radical scavenger
-few controlled studies-
-active agents-flavone glycosides-see above for effects
-side effects-headaches, dizziness, palpitations
                      
            

13. -anti-platelet aggregatory
Fibre-Based Herbal Medicines
Garlic
       -lower cholesterol
      -anti-platelet aggregatory
                      
- a number of controlled studies-
-active agents-allicin-see above for functions
-side effects-heartburn, flatulence
-anticoagulant function synergy
            

14. St. John's Wort -depression -anxiety Fibre-Based Herbal Medicines
a few well- controlled studies-
-active agents-MAO inhibitor-fights depression
-side effects-fatigue, allergic reactions, photosensitivity
          
                      
            

15. Golden seal -canker sores Fibre-Based Herbal Medicines
                      
a number of controlled studies-
-active agents-alkaloids-see above for functions
-side effects-none reported
            

16. -rheumatoid arthritis
Fibre-Based Herbal Medicines
Glucosamine
           -rheumatoid arthritis
                      
            

17. -rheumatoid arthritis
Fibre-Based Herbal Medicines
Chondroitin sulphate
            -rheumatoid arthritis
                      
            

18. Regulatory considerations what should be regulated, how and by who?
Fibre-Based Herbal Medicines
Regulatory considerations
what should be regulated, how and by who?
                      
            

19. Summary-figure 5.2 Gropper -no satisfactory definition of fibre
Fibre-Based Herbal Medicines
Summary-figure 5.2 Gropper
-no satisfactory definition of fibre
-SCFAs provide energy therefore fibre is
energy yielding
-varied soluble and insoluble fibre content in
different foods-implications for such
differences?