Probiotics and prebiotics
Pasteur made the prophetic statement that life sans microbes would be impossible. It was Metchnikoff who in 1907 came up with idea of positive role of some bacteria. Lilly & Stillwell coined term probiotic in1965. A 2001 FAO/WHO report defines probiotic as live microorganisms when given in adequate amounts confer benefit to the host.
The intestinal bacteria participate in normal functioning of gut:
- Structure and function e.g gut transit is delayed in germ-free animals.
- Biochemical interactions
- Immunology
- Maturation of blood vessels
- Gene expression
- Maintaining body weight
Potentially helpful actions of gut bacteria
- Reduce or eliminate pathogens
- Reduce/eliminate toxins/carcinogens
- Release nutrients/antioxidants, growth factors
- Impact on immune function
- Synthesize vitamins (K, FA, B group)
Prebiotics
As mentioned in the book Natural Stomach Care, these are the substances that provide substrate for fermentation by the intestinal bacteria. They are usually undigested food, mostly plant food. They are also known as colonic foods. They involved in the following functions in the intestines.
- Maintain mucosal growth
- Water electrolyte balance
- Provide Energy/nutrients for host/bacteria
- Stimulate growth of flora
Clinical studies
Probiotics, prebiotics as well as combined probiotics and prebiotics have been studied in many digestive illnesses like infantile colic, infectious diarrhea, travelers diarrhea, inflammatory bowel disease, antibiotic induced diarrhea, recurrent C. difficile colitis and irritable bowel syndrome.
Studies have also examined the impact of probiotics in non-digestive illnesses like atopic dermatitis, dental caries, gingivitis, postoperative infections, infections in liver transplant patients, preventing colds and sickness-related absenteism, baby growth etc.
Many of these studies have been very positive leading to introduction of multiple commercial products into the market. However, each product is different with respect to the type, number of strains and bacterial count. Just like antibiotics, some antibiotics may work in certain situations and not the others.
Properties of an ideal probiotic
- Ability to survive through gut
- Able to proliferate and colonize gut
- Safe and effective
- Maintain potency for the shelf-life
Myths about probiotics
- Alters the composition
- Permanent homeliness
- Impact on bowel ecosystem


I'm doing a research project on blogs in the Jackson, MS area. Would you mind e-mailing me so I can ask you a few questions? Thanks very much!
Posted by:Holly | February 03, 2007 at 06:12 PM