Microencapsulated bile salt hydrolase producing Lactobacillus reuteri for oral targeted delivery in the gastrointestinal tract
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- Martoni, C., Bhathena, J., Urbanska, A.M. et al. Appl Microbiol Biotechnol (2008) 81: 225. 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 × 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.