ABSTRACT
Probiotics are live microorganisms that confer health benefi ts on the host when they are administered in adequate numbers (Coman et al. 2012, da Cruz et al. 2007, FAO/WHO 2002, Saad et al. 2012). Probiotics are supplements or foods that contain viable microorganisms that cause alterations of the microfl ora of the host. Probiotic microorganisms are typically members of the genera Lactobacillus, Bifi dobacterium, and Streptococcus (Farnworth et al. 2007). These bacteria are fermentive, obligatory, or facultative anaerobic organisms. They typically produce lactic acid. Their inherent biological properties enable them to predominate and surpass potential pathogenic microorganisms in the human digestive tract. These microbes produce small molecular metabolic byproducts that set forth benefi cial regulatory infl uence on host biological functions, including short-chain fatty acids such as butyrate. The most studied probiotic bacteria to date include Lactobacillus rhamnosus GG (LGG), Bifi dobacterium lactis, and Streptococcus thermophilus. These probiotic bacteria are biologically different from the Gramnegative, motile, non-lactic-acid-producing bacteria such as Klebsiella, Pseudomonas, Serratia, and Proteus species, which also may be prominent fl ora in the human digestive system. These potentially harmful bacteria may
Ege University, Faculty of Engineering, Department of Food Engineering, 35100, Bornova, Izmir, Turkey.
