BIBC 120 fiber

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BIBC 120 fiber
2015-02-04 19:01:48

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  1. What is fiber?
    plant material that cannot be digested
  2. What are soluble fibers?
    Fibers that can be broken down by the gut microbiota
  3. What are two types of insoluble fiber?
    Cellulose (glucose with β-1,4 linkages) and hemicellulose
  4. What are three types of soluble fiber?
    β-glucans, pectin, and gums
  5. What are the benefits of fiber?
    • soluble fiber increases viscosity of GI tract contents
    • insoluble fiber adds bulk to feces, stimulating peristalsis and speeding movement through colon
    • slows gastric emptying and increases time for nutrient absorption in the small intestine
    • stimulates growth of colon microbiota
  6. What are the microbiota?
    collection of bacterial species inhabiting the colon
  7. What is the microbiome?
    Collection of genes from microbiota
  8. How are sterile infant colons colonized?
    from the environment, mostly Bifidobacterium species
  9. At what age is adult microbiota established?
    2-3 years
  10. What type of metabolism do most microbiota show?
    obligate anaerobes
  11. What is one type of faculative anaerobe?
    E. Coli
  12. What is produced during bacterial fermentation?
  13. What are the three SCFAs?
    butyrate, propionate, acetate
  14. What do SCFAs do in the GI tract?
    regulate immune response, which in essence, regulates inflammation
  15. What is the consequence of too little immune response?
    infection by pathogenic bacteria
  16. What is the consequence of too much immune response?
    inflammatory disease of intestine
  17. What did the Atarashi experiment show?
    Collection of microbiota was inoculated in the sterile colon of a mouse. This resulted in more Tregs in intestinal lining which provided resistance to inflammatory colitis.
  18. What did the Trompette experiment show?
    Control mouse was fed 4% diet while another mouse was fed a diet of <0.3% fiber. Control developed a more diverse microbiota and resulted in much less inflammation. The low-fiber diet mouse had a less diverse microbiota and significantly greater inflammation in lungs.
  19. What are probiotics?
    Taking in live bacterial cultures in food or dietary supplements
  20. What are prebiotics?
    Foods or supplements that promote the growth of beneficial microbiota.