Acid and Bile Tolerance and Cholesterol Removal Ability of Lactobacilli Strains

• Published in: Journal of dairy science Vol. 88; no. 1; pp. 55 - 66
• Main Authors: Liong, M.T., Shah, N.P.
• Format: Journal Article
• Language: English
• Published: Savoy, IL Elsevier Inc 01.01.2005; Am Dairy Sci Assoc; American Dairy Science Association
• Subjects: acid tolerance; Acids; Animal productions; Bile; bile tolerance; Biological and medical sciences; cell membranes; Cholesterol - metabolism; Cholesterol - pharmacology; cholesterol assimilation; fatty acid composition; Fatty Acids - analysis; Food industries; Fundamental and applied biological sciences. Psychology; Hypercholesterolemia - therapy; lactobacilli; Lactobacillus; Lactobacillus - chemistry; Lactobacillus - growth & development; Lactobacillus - physiology; Lactobacillus acidophilus; Lactobacillus casei; Milk and cheese industries. Ice creams; Probiotics; strain differences; Terrestrial animal productions; Vertebrates; lactobacilli; acid tolerance; LDL; cholesterol assimilation; bile tolerance; MRS; Ability; Lactic acid bacteria; Tolerance; Lipids; Survival; Cholesterol; Strain; Bile acid; Dairy industry; pH; Bacteria; Lactobacillaceae; Lactobacillus
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.s0022-0302(05)72662-x

Eleven strains of lactobacilli were studied for their acid and bile tolerance. Possible mechanisms of cholesterol removal by strains of lactobacilli were examined. Cholesterol assimilation as determined by the difference in cholesterol content in the medium before and after the incubation period showed that all lactobacilli strains were able to assimilate cholesterol at varying levels ranging from 12.03 to 32.25μg/mL. Cholesterol removal was associated with growth of cultures. Binding of cholesterol to lactobacilli cells was determined using growing, heat-killed, and resting cells in phosphate buffer. Cholesterol removed by dead and resting cells ranged from 0.79 to 3.82mg/g of dry weight compared with growing cells, which ranged from 4.53 to 16.03mg/g of dry weight. Fatty acid methyl esters, as quantified using gas chromatography, showed changes in lipid profiles in cells grown in the presence of cholesterol compared with those grown without cholesterol. Fatty acid profiles, especially of hexadecanoic, octadecanoic, total saturated, and unsaturated acids suggested that cholesterol from the medium was incorporated into the cellular membrane. These findings suggest that strains of lactobacilli could remove cholesterol via various mechanisms and may be promising candidates for use as a dietary adjunct to lower serum cholesterol in vivo.