isolated are identified according to the sugar fermentation test see anaerobe laboratory manual 4th ed ed by l v holdeman et al 1977 each bifidobacterium strain isolated from feces of newborn babies babies infants adults and elderly in total 120 strains is inoculated on the gam medium and cultured under anaerobic condition at 37 u00b0 c for 48 hours these bacteria are washed in phosphate buffer two times and subjected to heating at 100 u00b0 c for 30 min for use peyer 39 s patch is aseptically taken out from mouse intestine and placed in a solution of dispase 1 5 mg dispase ml joklik modified mem and then stirred at 37 u00b0 c for 30 to 40 minutes to recover single cells separated into the solution such procedure is repeated 4 or 5 times before centrifuge and washing to obtain peyer 39 s patch the isolated bifidobacterium strains 120 strains obtained after repeating three times the procedures for separation into single colonies were examined of their iga induction potential iga production was determined as follows cells of peyer 39 s patch 5 u00d7 10 5 and each of a variety of bacterial strains in suspension at a concentration of od 660 0 275 were placed in each well of a 96 well microtiter plate and cultured under 5 co 2 air at 37 u00b0 c in the eagle medium containing 5 fetal calf serum eagle mem manufactured by nissui pharmaceuticals co ltd 9 4 g l 200 mm glutamine 10 ml l.