Mechnikoff (1907) first introduced the probiotic concept in 1908, which observed the long life of Bulgarian peasants, who consumed fermented milk foods. He suggested that lactobacilli might counteract the putrefactive effects of gastrointestinal metabolism. In the century, which is elapsed since Metchnikoff”s research, scientists and consumers have accepted the probiotic concept throughout the world (Fuller, 1992). In the world, the concept of providing functional foods including beneficial components rather than removing potentially harmful components is gaining ground in recent years. It may consider a functional food with the special property of containing live, beneficial microorganisms. Functional foods and nutraceuticals can prevent and treat diseases. Yogurt and other fermented milks containing probiotics may be considered the first functional foods.
More specifically, Fuller (1992) defined probiotics as a live microbial feed supplement that beneficially affects the host beyond correcting for traditional nutrient deficiencies by improving the intestinal balance. The increasing cost of health care, the steady increase in life expectancy and the desire of the elderly for improved quality of their lives are driving factors for research and development in the area of functional foods. Although, the concept of functional foods was introduced long ago with Hippocrates and his motto let food be your medicine, fairly recently the body of evidence started to support the hypothesis that diet may play an important role in modulation of important physiological functions in the body. Among a number of functional compounds recognized so far, bioactive components from fermented foods and probiotics certainly take the center stage due to their long tradition of safe use and established and postulated beneficial effects.
The first clinical trials in the 1930s focused on the effect of probiotics on constipation and research has steadily increased since then. Today probiotics are available in a variety of food products and supplements. Food products containing probiotics are almost dairy products that due to the historical association of lactic acid bacteria with fermented milk. The fermentation of dairy foods presents one of the oldest methods of long-term food preservation. The origin of fermented milk can be traced back long before the Phoenician era and placed in the Middle East. Traditional Egyptian fermented milk products, Laban Rayeb and Laban Khad, were consumed as early as 7000 BC. Their tradition claims that even Abraham owed his longevity to the consumption of cultured milk (Kosikowski and Mistry, 1997). Initially, established in the middle and Far East of Asia, the tradition of fermenting milk was spread throughout the east Europe and Russia by the Tartars, Huns and Mongols during their conquests. As a consequence, a wide range of fermented dairy products still exists in these regions and some popular products such as yoghurt and kefir are claimed to originate from the Balkans and Eastern Europe.
The World Health Organization’s (WHO) definition of probiotics, issued in 2001 is as follows: “live microorganisms which when administered in adequate amounts confer a beneficial health effect on the host.”