Spore-forming probiotic bacteria Clostridium butyricum was used to assess its in vitro potential probiotic properties of both spore and vegetative cell form. Tested items included acid (pH 2-4) tolerance, bile salts (0.1-0.4%) tolerance, adhesiveness and antagonistic effect on the pathogenic C. perfringens. Lactobacillus reuteri and Bifidobacterium bifidum were selected as reference strains for comparison in those mentioned characteristics. C. butyricum spore exhibited higher survival rate than its vegetative cells in acid and bile conditions. The vegetative cell of C. butyricum (70.5%), L. reuteri (82.4%) and B. bifidum (77.8%) possessed good adhesive properties. Nevertheless, C. butyricum spore showed low adhesiveness (8.2%). Spent culture supernatant (SCS) of C. butyricum could inhibit the growth of C. perfringens in the inhibition zone test. In vitro invasion assay also revealed the safety aspect of C. perfringens.
