title: Properties of Lactobacillus reuteri chitosan-calcium-alginate encapsulation under simulated gastrointestinal conditions.
abstract: The protective effects of encapsulation on the survival of Lactobacillus reuteri and the retention of the bacterium's probiotic properties under simulated gastrointestinal conditions were investigated. Viable counts and the remaining probiotic properties of calcium (Ca)-alginate encapsulated (A group), chitosan-Ca-alginate encapsulated (CA group), and unencapsulated, free L. reuteri (F group) were determined. Encapsulation improved the survival of L. reuteri subjected to simulated gastrointestinal conditions, with the greatest protective effect achieved in the CA group. The degree of cell membrane injury increased with increasing bile salt concentrations at constant pH, but the extent of injury was less in the encapsulated than in the free cells. Adherence rates were, in descending order: CA (0.524%)>A (0.360%)>F (0.275%). Lactobacillus reuteri cells retained their antagonistic activity toward Listeria monocytogenes even after incubation of the lactobacilli under simulated gastrointestinal conditions. Displacement of the pathogen by cells released from either of the encapsulation matrices was higher than that by free cells. The safety of L. reuteri was demonstrated in an in vitro invasion assay.
authors.affiliation: Department of Nutrition, China Medical University, Taichung, Taiwan, ROC.
authors.forename: Hui-Ying
authors.initials: HY
authors.lastname: Huang
authors.affiliation: Department of Nutrition, China Medical University, Taichung, Taiwan, ROC.
authors.forename: Yi-Ju
authors.initials: YJ
authors.lastname: Tang
authors.affiliation: Department of Food Science and Biotechnology, National Chung-Hsing University, Taichung, Taiwan, ROC.
authors.forename: V An-Erl
authors.initials: VA
authors.lastname: King
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Internal Medicine, China Medical University Hospital, College of Medicine, China Medical University, Taichung, Taiwan, ROC.
authors.forename: Jen-Wei
authors.initials: JW
authors.lastname: Chou
authors.affiliation: Department of Nutrition, China Medical University, Taichung, Taiwan, ROC.
authors.forename: Jen-Horng
authors.initials: JH
authors.lastname: Tsen
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001647:Bile Acids and Salts; D002118:Calcium / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D004339:Drug Compounding; D041981:Gastrointestinal Tract / Q000382:microbiology*; D052200:Limosilactobacillus reuteri / Q000502:physiology*; D050296:Microbial Viability; D008863:Microspheres; D019936:Probiotics / Q000008:administration & dosage*
chemical_list: D000464:Alginates; D001647:Bile Acids and Salts; D048271:Chitosan; D002118:Calcium
keywords: Lactobacillus reuteri; Listeria monocytogenes; chitosan–calcium-alginate encapsulation; probiotic properties; simulated gastrointestinal conditions