Probiotics are small microorganisms such as bacterias or yeasts that impart some kind of health benefit to their host organism. When administered in small, consistent doses they can improve overall vitality in a number of ways. Etymologically, the word probiotic comes from the Greek, meaning "for life". Friendly bacteria exist naturally in the digestive system and can modulate a number of health conditions. When natural levels fluctuate due to antibiotic consumption, stress, or nutritional deficiencies, health problems can ensue.
E. Metchnikoff is credited to be the father of the probiotic concept. In his famous book The Prolongation of Life, he stated that "The dependence of the intestinal microbes on the food makes it possible to adopt measures to modify the flora in our bodies and to replace the harmful microbes by useful microbes" (Metchnikoff, 1907). This sentence describes in a clear way what we call probiotics or the use of health promoting bacteria able to exert a positive role on intestinal flora.
Metchnikoff, at that time a professor at the Pasteur Institute in Paris, proposed the hypothesis that the aging process results from the activity of putrefactive (proteolytic) microbes producing toxic substances in the large bowel. Proteolytic bacteria such as clostridia, which are part of the normal gut flora, produce toxic substances including phenols, indols and ammonia from the digestion of proteins. According to Metchnikoff these compounds were responsible for what he called "intestinal auto-intoxication", which caused the physical changes associated with old age.
It was at that time known that milk fermented with lactic-acid bacteria inhibits the growth of proteolytic bacteria because of the low pH produced by the fermentation of lactose. Metchnikoff had also observed that certain rural populations in Europe, for example in Bulgaria and the Russian steppes who lived largely on milk fermented by lactic-acid bacteria were exceptionally long lived. Based on these facts, Metchnikoff proposed that consumption of fermented milk would "seed" the intestine with harmless lactic-acid bacteria and decrease the intestinal pH and that this would suppress the growth of proteolytic bacteria. Metchnikoff himself introduced in his diet sour milk fermented with the bacteria he called "Bulgarian Bacillus" and found his health benefited. Friends in Paris soon followed his example and physicians began prescribing the sour milk diet for their patients.
The word probiotics was used for the first time in the '60s, to define compounds produced by microorganisms able to stimulate the growth of other microorganisms (Lilly and Stillwell, 1965). Fuller (1989), in order to point out the microbial nature of probiotics, redefined the word as "A live microbial feed supplement which beneficially affects the host animal by improving its intestinal balance". A similar definition was proposed in 1992 by Havenaar and Huius in 't Veld: " a viable mono or mixed culture of bacteria which applied to animal or man, beneficially affects the host by improving the properties of the indigenous flora.”
In more recent years, the meaning of this word has been redefined several times and today a widely accepted definition of probiotics is: " live microorganisms, which when consumed in adequate amounts, confer a health effect on the host” (Guarner and Schaafsma, 1998).*
This article was written by Nakita Valerio, B.A, CSN, BMSA Technician. She has been working for Optimum Health Vitamins since 2007, during which she has gained a deep appreciation and understanding for the complexities of human nutrtition, and has spent hundreds of hours researching the topic. Her current position is online media assistant - a job she currently enjoys from Morocco!
Disclaimer: The above information is provided for informational purposes only and is not intended to replace the advice of your physician.