Enrichment of Bifidobacterium longum subsp. infantis ATCC 15697 within the human gut microbiota using alginate-poly-l-lysine-alginate microencapsulation oral delivery system: an in vitro analysis using a computer-controlled dynamic human gastrointestinal model

Abstract

This study evaluates alginate-poly-l-lysine-alginate Bifidobacterium longum subsp. infantis ATCC 15697-loaded microcapsules to enrich the human gut microbiota. The cell survival of alginate-poly-l-lysine-alginate microencapsulated B. infantis ATCC 15697 in gastric acid, bile, and through human gastrointestinal transit was investigated, as well as the formulation’s effect on the gut microbiota. Results show that microencapsulation increases B. infantis ATCC 15697 cell survival at pH1.0 (33.54?±?2.80% versus <1.00?±?0.00%), pH1.5 (41.15?±?2.06% versus <1.00?±?0.00%), pH2.0 (60.88?±?1.73% versus 36.01?±?2.63%), pH3.0 (75.43?±?1.23% versus 46.30?±?1.43%), pH4.0 (71.40?±?2.02% versus 47.75?±?3.12%) and pH5.0 (73.88?±?3.79% versus 58.93?±?2.26%) (p?<?0.05). In addition, microencapsulation increases cell survival at 0.5% (76.85?±?0.80% versus 70.77?±?0.64%), 1.0% (59.99?±?0.97% versus 53.47?±?0.58%) and 2.0% (53.10?±?1.87% versus 44.59?±?1.52%) (p?<?0.05) (w/v) bile. Finally, daily administration of alginate-poly-l-lysine-alginate microencapsulated B. infantis ATCC 15697 in a human gastrointestinal model induces a significant enrichment of B. infantis within the ascending (184.51?±?17.30% versus 53.83?±?17.82%; p?<?0.05), transverse (174.79?±?25.32% versus 73.17?±?15.30%; p?<?0.05) and descending (94.90?±?25.22% versus 46.37?±?18.93%; p?>?0.05) colonic microbiota.