The activities and modes of probiotic action of lactic acid bacteria isolated from infant feces were investigated for alternative application in the prevention and
biotherapy of
colon cancer. From a total of 81 isolates of Gram-positive rod and cocci bacteria obtained from healthy infants, only 15 isolates had the probiotic criteria which included growth inhibition against eight food-borne pathogens, no blood
hemolysis, and tolerance to gastrointestinal tract properties such as pH 2.5 and 0.3 %
bile salt. Four probiotic bacteria showed antiproliferation of
colon cancer cells with the use of MTT and
Trypan blue exclusion assay at the rates of 17-35 %. Through comparison of probiotic
16S rRNA sequences, they were identified as Pediococcus pentosaceus FP3, Lactobacillus salivarius FP25, L. salivarius FP35, and Enterococcus faecium FP51. Finding the mechanism of proliferative inhibition of
colon cancer cells in this study indicated synergic induction by probiotic bacteria directly adhered to these
cancer cells and triggered the bioproduction of
short-chain fatty acids, mainly butyric and
propionic acids. This study suggested that the use of these probiotics may be suitable as an alternative bioprophylactic and biotherapeutic strategy for
colon cancer.