BIBC 120 Lecture Notes - Gut Flora, Dietary Fiber, Firmicutes
24 May 2018
School
Department
Course
Professor
week 4.2
soluble fiber → microbiota → SCFAs
- link between the potential inflammation regulating properties of the gut microbiota and
the established health benefits of dietary fiber?
o aye…orrelatio etee systei leels of iflaatio ad risk for
diseases (heart diseases/type 2 diabetes, cancer)
o possibly inverse correlation between dietary fiber and systemic inflammation
Diet Influences the Composition and Activity of the Gut Microbiota
- Group 1: 15 children from city in Western Europe—standard Western diet (higher
protein/higher fat/less protein, vegetable and fiber); Firmicutes more abundant
- Group 2: 14 children from rural African village—primarily vegetarian diet, high in starch
and fiber; Bacteroidetes more abundant—Greater production of SCFA
- Correlation
Dietary Sources of Fiber
- whole grains, fruits, vegetables, legumes
o apples, bananas, broccoli, carrot, potato, oats, kidney/pinto beans,
DRI alues for fier do’t eed to ko alues
- AI (adequate intake) for total fiber: 19 – 38 grams/day (see inside cover of textbook for
your AI)
- No DRI values yet for soluble vs. insoluble fiber, but guidelines published by the NIH
recommend 5 – 10 grams/day of soluble fiber
Interventions to Increase the Health-Associated Intestinal Microbiota
- Probiotics: Taking in live bacterial cultures in food or dietary supplements
o Lactobacillus species (Firmicutes)
o Bifidobacteria
- Prebiotics: Foods or supplements that promote the growth of beneficial microbiota
o High-fiber foods, fiber supplement
o Oligosaccharides occur naturally in breast milk; added to baby formula
DIGESTION AND ABSORPTION OF PROTEIN
1) Denaturation
2) Hydrolysis of peptide bonds
Stomach
- low pH denaturation
- A digestive protease: pepsinogen (inactive) → pepsin (active), autocatalytic cleavage (in
low pH of the stomach)
o Digestive proteases
▪ Secreted as inactive proenzymes, or zymogens to prevent proteolytic
damage to organs of GI tract
▪ Cleavage of a fragment from the N-terminus of the protease activates it
Small Intestine
- enterocytes of mucosa
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Diet influences the composition and activity of the gut microbiota. Group 1: 15 children from city in western europe standard western diet (higher protein/higher fat/less protein, vegetable and fiber); firmicutes more abundant. Group 2: 14 children from rural african village primarily vegetarian diet, high in starch and fiber; bacteroidetes more abundant greater production of scfa. Whole grains, fruits, vegetables, legumes: apples, bananas, broccoli, carrot, potato, oats, kidney/pinto beans, Dri (cid:448)alues for fi(cid:271)er (cid:894)do(cid:374)"t (cid:374)eed to k(cid:374)o(cid:449) (cid:448)alues(cid:895) Ai (adequate intake) for total fiber: 19 38 grams/day (see inside cover of textbook for your ai) No dri values yet for soluble vs. insoluble fiber, but guidelines published by the nih recommend 5 10 grams/day of soluble fiber. Probiotics: taking in live bacterial cultures in food or dietary supplements: lactobacillus species (firmicutes, bifidobacteria. Prebiotics: foods or supplements that promote the growth of beneficial microbiota: high-fiber foods, fiber supplement, oligosaccharides occur naturally in breast milk; added to baby formula.
