BC down regulated HER-2 by 6.7 folds but there was no significant difference between the effectiveness of all the other 4 bacterial groups in HER-2 down regulation (LC, L. reuteri, B. breve, and L+B decreased HER-2 expression by 3.9, 3.9, 3.6, 3 folds, respectively). This evidence concerns the gene ERBB2 and breast cancer.