ABSTRACT
Probiotics are defi ned by FAO/WHO (2002) as live microorganisms, which when administered in adequate amounts confer a health benefi t on the host. A number of bacterial strains (and sometimes yeast strains) have been characterised, proposed and applied in food matrices as human probiotics. These probiotics have been shown to be benefi cial for treatment and prevention of allergies, irritable bowel syndrome, infl ammatory bowel disease, viral diarrhoea and constipation, immune modulation and promotion of oral health by intervention studies (reviewed by Collado et al. 2009). The majority of probiotics in use are classifi ed in the genera Bifi dobacterium and Lactobacillus (Ouwehand et al. 2002a). Lactobacillus spp. are members of the lactic acid bacteria (LAB) group, and other members of the group, e.g., Leuconostoc, Pediococcus, Enterococcus, Lactococcus and Oenococcus, are also assessed on the basis of their probiotic properties mainly by in vitro studies. Bifi dobacterium spp. share some similar characteristics to LAB but differentiate from LAB on their phylogenetic positions and high GC content in their genomes. These organisms usually originate in human faeces, breast-milk, and fermented and non-fermented foods. However, these origins usually have complex microbiota, and sometimes target organisms are not
1 Department of Food and Cosmetic Science, Department of Bioindustry, Tokyo University of Agriculture, Hokkaido, Japan.
