Journal of Bacteriology & Parasitology

Abstract

A Comparative Study of Some Functional Properties of Lactobacillus and Enterococcus Isolated from Feces of Normo and Hyper-Cholesterolemic Humans

María de Lourdes Reyes-Escogido, Claudia Mercedes Gómez-Navarro, Silvia Daniela Ramírez-Ardila, Francisco Martínez-Pérez and Rodolfo Guardado-Mendoza

There have been reports of an association between an imbalance of gastrointestinal microbiota and several kinds of diseases, mainly metabolic diseases. Lactobacillus and Enterococcus are two genera that form part of the native gastrointestinal microbiota. In this work, we isolated, identified and characterized 26 strains of Lactobacillus and 23 strains of Enterococcus from the feces of normo and hypercholesterolemic humans. We compared the behavior exhibited by all strains at acid pH and in presence of bile salts, their sensitivity to antibiotics, and their ability to hydrolyze bile salts and to reduce cholesterol in vitro. The highest percentage of all isolated and characterized Lactobacillus strains was from the normocolesterolemic group; in the hypercholesterolemic group, most strains belonged to the Enterococcus genus. The Lactobacillus strains showed greater capacity to reduce cholesterol levels; although this capacity has been related to bile salt hydrolase activity, four of the strains we isolated showed no such activity, but still reduced cholesterol. All strains of both genera isolated from normocholesterolemic participants showed a highest rate of cholesterol reduction than those isolated from hypercholesterolemic participants. Furthermore, the Lactobacillus strains showed greater resistance at pH 2.0, while strains of both genera showed similar survival rates at pH 3.0 and in the presence of bile salts after 24 h. These results support the evidence that a microbial imbalance involving the depletion of beneficial bacteria could be detrimental to the health of the host.