Probiotics Properties of Lactobacilli: Cholesterol reduction and bile salt hydrolase activity

FONT DE VALDEZ, GRACIELA; TARANTO, MARIA PIA

Food Microbiology Protocols. Series Methods in Molecular Biology

Humana Press Inc

Lugar: New Jersey; Año: 2000; p. 173 - 181

Amongst the probiotic effects attributed to lactic acid bacteria (LAB), the assimilation of cholesterol (1) would be of particular interest for reducing the absorption of dietary cholesterol from the digestive system into the blood. Besides, several studies have indicated that the cholesterol removal would be related to the ability of the cultures to deconjugate bile salts (2). Bile tolerance and gastric juice resistant (3) are another important characteristics of probiotic lactic acid bacteria used as adjuncts as they enable them to survive, to grow, and to perform their beneficial action in the gartrointestinal tract (GIT). Although the degree of tolerance required for maximum growth in the GIT is not known, it seems reasonable that the most bile- and acid-resistant species should be selected. The techniques used to selecting LAB for probiotic purposes will be considered under the following headings: 1.      Bile tolerance, using differents bile salts concentrations 2.      Resistance to gastric juice  3.      “In vitro” cholesterol reduction on the presence of bile salts Bile salt hydrolase activity, determined by three complementary methods: plate assay, colorimetric method, and High Pression Liquid Chromatography (HPLC)