A total of 5 Bifidobacterium spp. isolated from pig and children' feces and 6 Lactobacillus spp. from chicken feces were examined for expression of aggregation, cell surface hydrophobicity (CSH) and adherence to intestinal mucin. Co-aggregation activity was seen in 3 strains of auto-aggregative bifidobacteria and 4 auto-aggregative strains of Lactobacillus spp. with 2 enterohemorrhagic E. coli (O157). CSH correlated with Lactobacillus auto-aggregating activity and adherence to mucin but the correlation between Bifidobacterium adherence to mucin and CSH was not confirmed.