Prebiotics

Prebiotics are non-digestible food substances that promote the growth of beneficial bacteria in the gastrointestinal tract. Chemically, prebiotics are oligosaccharides and examples are inulin-type fructans, fructooligosacharides and oligofructoses, which are present in many fruits and vegetables.
Prebiotics resist digestion in the upper part of the gastrointestinal tract and are fermented by endogenous anaerobic micro-organisms in the colon to produce lactic acid and short chain carboxylic acids (e.g. acetic, butyric and propionic acid). This fermentation provides metabolic substrates to the cells of the colon, stimulating growth of the bifidobacteria population.
Prebiotics also promote the absorption of calcium and magnesium, and possibly other minerals and trace elements within the colon. Evidence is also emerging that they may reduce serum lipid, particularly triglycerides. They are also being investigated for a possible protective effect in bowel cancer, constipation, inflammatory bowel conditions, allergic dermatitis and lactose intolerance.