Microencapsulated bile salt hydrolase producing Lactobacillus reuteri for oral targeted delivery in the gastrointestinal tract

• Published in: Applied microbiology and biotechnology 2008-11, Vol.81 (2), p.225-233
• Main Authors: Martoni, Christopher, Bhathena, Jasmine, Urbanska, Aleksandra Malgorzata, Prakash, Satya
• Format: Article
• Language: English
• Subjects: Acids; Acids - pharmacology; Amidohydrolases - metabolism; Anti-Bacterial Agents - pharmacology; Bacteria; Bifidobacterium - metabolism; Bifidobacterium longum; Bile; Bile Acids and Salts - metabolism; Bile salt hydrolase; Bioengineering; Biological and medical sciences; Biotechnological Products and Process Engineering; Biotechnology; Capsules - metabolism; Capsules - pharmacokinetics; Food products; Fundamental and applied biological sciences. Psychology; gastrointestinal system; Gastrointestinal Tract; Hydrogen-Ion Concentration; L. reuteri; Lactobacillus reuteri; Lactobacillus reuteri - metabolism; Life Sciences; Microbial Genetics and Genomics; Microbial Viability; Microbiology; Microcapsule; Microorganisms; Models, Theoretical; Oral delivery; Probiotic bacteria; Probiotics; Probiotics - metabolism; Probiotics - pharmacokinetics; Salt; Stomach; Studies; Time Factors
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-008-1642-8

This is the first study of its kind to screen probiotic lactic acid bacteria for the purpose of microencapsulating a highly bile salt hydrolase (BSH)-active strain. A Lactobacillus reuteri strain and a Bifidobacterium longum strain were isolated as the highest BSH producers among the candidates. Microcapsules were prepared with a diameter of 619 ± 31 μm and a cell load of 5 x 10⁹ cfu/ml. Post de Man, Rogosa, and Sharpe broth-acid challenge, L. reuteri microcapsules metabolized glyco- and tauro-conjugated bile salts at rates of 10.16 ± 0.46 and 1.85 ± 0.33 μmol/g microcapsule per hour, respectively, over the first 2 h. Microencapsulated B. longum had minimal BSH activity and were significantly (P < 0.05) more susceptible to acid challenge. Further testing of L. reuteri microcapsules in a simulated human gastrointestinal (GI) model showed an improved rate, with 49.4 ± 6.21% of glyco-conjugates depleted after 60 min and complete deconjugation after 4 h. Microcapsules protected the encased cells in the simulated stomach maintaining L. reuteri viability above 10⁹, 10⁸, and 10⁶ cfu/ml after 2 h at pH 3.0, 2.5, and 2.0, respectively. Results show excellent potential for this highly BSH-active microencapsulation system in vitro, highlighted by improved viability and substrate utilization in simulated GI transit.