Mechanisms of cholesterol removal by lactobacilli under conditions that mimic the human gastrointestinal tract

• Published in: International dairy journal Vol. 20; no. 3; pp. 169 - 175
• Main Authors: Lye, Huey-Shi, Rahmat-Ali, Gulam Rusul, Liong, Min-Tze
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.03.2010; [Amsterdam]: Elsevier Science; Elsevier
• Subjects: assimilation (physiology); bile salts; Biological and medical sciences; cholesteremic effect; cholesterol; Food industries; Food microbiology; Fundamental and applied biological sciences. Psychology; humans; in vitro digestion; Lactobacillus; Milk and cheese industries. Ice creams; Human; Lactic acid bacteria; Digestive system; Dairy industry; Bacteria; Lactobacillaceae; Lipids; Gastrointestinal; Cholesterol; Mechanism; Lactobacillus
• ISSN: 0958-6946; 1879-0143
• DOI: 10.1016/j.idairyj.2009.10.003

Five strains of lactobacilli were studied for their ability to remove cholesterol in vitro under conditions that mimic the human gastrointestinal tract. The highest assimilation of cholesterol was observed in media supplemented with oxgall and the lowest in the presence of taurocholic acid. Scanning electron micrographs showed that cholesterol was adhered to the cellular surface of lactobacilli cells. Resting and dead cells were able to remove cholesterol although in small amounts. Additionally, inhibition of cholesterol micelles formation was observed in the presence of bile salts. All strains were able to deconjugate bile salts, where higher deconjugation was observed in the presence of sodium glycocholate compared with other bile salts studied. All strains also exhibited bile salt hydrolase activity and most strains showed higher substrate specificity towards glycine-conjugated bile than towards taurine-conjugated bile. The results indicated that lactobacilli could remove cholesterol in vitro via various mechanisms, and may exert such hypocholesterolaemic effects in vivo.