Safety Assessment and Anticancer Potential of Fermented Milk Containing Enterococcus faecium KMJC93 Isolated from Traditional Sources

The objective of the present research was to assess the safety and anticancer effect of fermented milk containing Enterococcus strains. Initially, six autochthonous Enterococcus strains were molecularly identified. To demonstrate their safety in vitro, six strains were evaluated for hemolysis and vancomycin sensitivity. Furthermore, they were also studied for their milk fermentation ability. To confirm the safety of fermented milk, its toxic effect on normal mouse fibroblast cell (L929) was examined. Selected fermented milk was evaluated for anticancer activity against human colon cancer cell (HT-29). The findings showed that six Enterococcus strains were E. faecium KMJC41 (OP764046), E. faecalis KMJC54 (OP764047), E. faecalis KMJC62 (OP764048), E. faecium KMJC71 (OP764049), E. faecium KMJC93 (OP764050), E. faecium KMCH3 (OP764051). Among them, three strains including E. faecium KMJC93, E. faecium KMJC41 and E. faecalis KMJC62 did not show hemolysis and were sensitive to vancomycin. E. faecium KMJC93 and E. faecium KMJC41 showed milk fermentation capability. The cytotoxicity of fermented milk with E. faecium KMJC93 and E. faecium KMJC41 on normal mouse fibroblast cell was 7% and 24%, respectively. Since HT-29 cell viability treated with milk fermented by E. faecium KMJC41 was below 90%, hence, fermented milk with E. faecium KMJC41 was excluded from the apoptosis test. Fermented milk with E. faecium KMJC93 induced 46% apoptosis in HT-29 cells. Therefore, it was concluded that the fermented milk with E. faecium KMJC93 was safe and presented promising anticancer properties.