Effect of emulsification/internal gelation-based microencapsulation on the viability of Akkermansia muciniphila upon prolonged storage and simulated gastrointestinal passage

Akkermansia muciniphila is a common human intestinal commensal with a mucin-degrading nature. Its immunomodulatory characteristics and regulatory role of mucus layer and gut barrier integrity highlight the potential benefits of using this bacterium as an interventional player against inflammatory/cardio-metabolic disorders. In this work, we evaluate the effect of microencapsulation by the emulsification/internal gelation method on A. muciniphila survival during aerobic storage (0, 15, 30 and 95 days) and subsequent exposure to simulated gastrointestinal passage, in comparison with that of free cells. The present results show that microencapsulation by internal gelation promotes a 64.4 % entrapment efficacy of A. muciniphila cells (maintaining a 10⁸ order of magnitude for cell viability). Moreover, physical characterization showed that microparticles mean size was 53,5 ± 12,1 µm and, as observed by electron scanning microscopy, microcapsules were spherical in shape. More importantly, as storage time increased, encapsulated A. muciniphila demonstrated higher stability in GI conditions, when compared to its free counterpart. In conclusion, microencapsulation by internal gelation seems to be an appropriate strategy in protecting A. muciniphila against the detrimental gastrointestinal transit after long periods of aerobic refrigerated storage.