Comparison of Probiotic Characteristics in Lactobacillus acidophilus Strains

Twelve strains of Lactobacillus acidophilus isolated from feces of human or animal sources were tested for probiotic properties such as cholesterol assimilation, bile and acid tolerances, and CLA production. Although the cultures showed some variation with respect to each test, the 12 strains could be classified into 3 groups based on their ability to assimilate cholesterol. The cholesterol assimilation showed positive correlation with bile tolerance and negative correlation with acid tolerance. The cholesterol assimilation of L. acidophilus strains may not be related to the deconjugation activity, but may in fact be attributed to its bile tolerance. CLA production by lactic acid bacteria (LAB) exhibited a wide variation that ranged from 2.69 to 7.64 mg/g fat. CLA production of Bifidobacterium longum ATCC 15707 was the highest among the LAB tested, but there was no evidence for differences in CLA production between genus and species.