In Japan, milk and food companies have recently developed many functional yogurts using selected probiotic lactic acid bacteria (LAB) and Bifidobacterium strains. In 1991, the FOSHU (foods for specified health uses) system began instituted by the Ministry of Health, Labor and Welfare. In 2010, approximately 1,000 commercially available items were labeled as FOSHU products that are specially given brands showing good health effects for humans. Japanese commercial yogurts are classified into three type categories: fermented using selected probiotics, functional components added, and standard types. Many functions are considered in the selection of probiotics including competitive adhesion exclusion of enteritic pathogens, cholesterol lowering effects, and positive immuno-modulatory effects. Adhesion to the human intestine is one of the most important characteristics of probiotic LAB and bifidobacteria. Our new screening system for adhesive activity involves a combination of three methods: the rat colonic mucin-micro plate assay, the Carnoy’s histochemical staining method, and the carbohydrate probe binding assay. Recently, we developed a new screening assay using the BIACORE biosensor chip coated with human colon mucin (HCM). We found new LAB strains that recognize and specifically bind to the human ABO blood type antigens. We named these “blood type LAB”. We identified the molecular LAB binding mechanism occurring in the human intestine through unique adhesin molecules that are expressed on the bacterial cell surface as lectin-like proteins. Bacteria with strong adhesion ability improve gastrointestinal health by continuous proliferation in the intestine; and increase the chance of intake into the Peyer’s patches through M-cells that inhibit allergies because of LAB immune-stimulating activity. The future Japanese food market will contain superior functional yogurts containing adhesive effective probiotic LAB and bifidobacteria that are expected to be developed using our proposed mass screening system shown here.

• Tadao Saito(Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan)