Colanic acid (CA) is an exopolysaccharide found in Enterobacteriaceae. Recently, its ability to stimulate physical activity in mice and to prolong the lifespan of invertebrates has been described. In the current work, we use standard MTT assay, fluorescence microscopy, and flow cytometry to describe CA action on several cell lines of different origins. We observed slight antiproliferative activity against colorectal cancer (HCT-116), neuroblastoma (IMR-32), and myoblast (C2C12) cell lines at a concentration of 256 μg/mL, while other cell lines of non-cancerous origin (Vero, HPF) did not show any decrease in the MTT assay. In all cell lines, we observed a rearrangement of mitochondria localization using fluorescence microscopy. CA induces cell differentiation in the myoblast cell line (C2C12) at concentrations of 50–200 μg/mL. Briefly, we observed that the number of apoptotic cells increased and the metabolic activity in the MTT assay decreased, which was accompanied by changes in cell morphology, the quantity of ROS, and the potential of the mitochondrial membrane. Taken together, these results indicate that CA is specific in cytotoxicity to cell lines of different origins and can impact mitochondria and differentiation, consistent with its potential geroprotective function.