ABSTRACT
Elie Metchnikoff rst introduced the concept of probiotics in his book entitled Prolongation of Life in 1907. Many types of bacteria have since surfaced possessing probiotic properties and the most documented groups comprise of lactic acid bacteria (LAB) and bidobacteria. Many of these are associated with various habitats such as fermented dairy products and plant materials, but other habitats like soil, silage, and human oral cavity, intestinal tract, and vagina. Probiotics are currently dened as “live microorganisms that, when administered in adequate amounts, confer a benecial effect on the hosts” (FAO/WHO 2002). This denition has evolved much since the birth of the probiotic concept, with the earlier denition stressing on the need of the microorganisms to be alive and latter stating that it should be consumed. These were very much contributed by the initial roles of probiotics in regulating gut wellbeing, including the alleviation of lactose intolerance, improvement of diarrhea, and inhibition toward pathogenic bacteria in the gut; thus, probiotics need to be alive and delivered via the oral route to reach the gastrointestinal (GI) tract.
