Cholesterol reduction in vitro by novel probiotic lactic acid bacterial strains of Enterococcus isolated from healthy infants stool

The present study aimed to isolate and evaluate the potentiality of some probiotic lactic acid bacteria from infants stool to degrade and reduce cholesterol level in fermentation medium. Out of 50 lactic acid bacterial isolates recovered from healthy infants (3 to 18 months old) stool, two bacterial isolates W7 and Y1 showed highest cholesterol reduction percentage (68.38 and 71.6%, respectively). The cholesterol reduction potentiality by the two isolates W7 and Y1 were optimized to 94 and 98%, respectively, by studying the different cultural conditions; inoculum size, inoculum age, pH, incubation temperature, incubation period and cholesterol concentration. The gas chromatography analysis of the fermentation extract revealed that the resulted end product of cholesterol was 5á-cholestane-3à,25-diol (C27H48O2) of molecular weight 404. The selected bacterial isolate Y1 was identified phenotypically and genotypically as Enterococcus faecium and deposited in GenBank under the accession number KY788356.