Figure 4.

Proliferation of colorectal cancer cells treated with BM (A) and DMEM (B) fermented broth by adapted and normal Propionibacterium freudenreichii. Fermented broths were deproteinized to eliminate any possible cytotoxic effect from contaminating proteins. Pure SCFA at concentrations present on the fermented broth of non-adapted bacteria (0.9 g L⁻¹ acetate; 2.4 g L⁻¹ propionate) or adapted bacteria (0.6 g L⁻¹ acetate; 1.5 g L⁻¹ propionate) were used as a SCFA control. Cells were incubated for 48 h with BM and DMEM fermented broths and its respective controls. BM diluted in fresh DMEM medium and CRC cells conditioned medium diluted in fresh DMEM medium were used as a negative control of BM and DMEM fermented broths, respectively, and Hydrogen peroxide (1 mM) as a positive control. Values represent the mean ± standard error of the mean of at least three independent experiments. ^*p < 0.05; ^**p < 0.01; ^***p < 0.001 compared with negative control cells.