In HT-29 cells, treatment with B. bifidum H3-R2 and L. lactis KLDS4.0325 resulted in a decrease in Bcl-2 expression and an increase in Bax, caspase-3, and caspase-9 expression, suggesting that H3-R2 and KLDS 4.0325 may be able to control the levels of caspase and Bcl-2 family proteins to promote colon cancer cell apoptosis through the mitochondrial pathway. Here, CASP9 is linked to malignant colon neoplasm.