Optimizing spray-drying conditions for encapsulation of the next generation probiotic akkermansia muciniphila DSM 22959

Probiotics are defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host” [1]. Among those, Akkermansia muciniphila is one of the most promising candidates proposed as a next generation probiotic. This commensal bacterium has a high potential to be incorporated into foods or pharmaceutical formulations, due to its demonstrated relevant biological effects in several metabolic conditions [2, 3]. For its commercialisation as a probiotic, A. muciniphila must be successfully incorporated into a deliverable formulation. However, its anaerobic nature becomes important to develop a matrix that can confer them protection during the usually aerobic storage [4]. Among the several encapsulation methodologies, spray-drying is one of the most popular due to appealing characteristics in terms of operation, scale-up, costs and efficiency [5]. The present work aims to i) establish a suitable procedure to encapsulate A. muciniphila DSM 22959 using a spray-dryer, without prior encapsulation treatments, by optimizing the spray-drying settings and matrices; and ii) evaluate spray-dried A. muciniphila viability during storage under aerobic conditions at different temperatures. Results: The most suitable matrix for A. muciniphila encapsulation by spray-drying was skim milk. Adequate conditions for spray-drying processing were established, considering inlet and outlet temperatures, to ensure maximum viability upon processing. Skim milk encapsulated A. muciniphila cells also showed high stability during storage for 30 days, under aerobic conditions, both at 22 oC and, specially, at 4 oC. Conclusions: Spray-drying seems to be a promising technique to encapsulate A. muciniphila, particularly using skim milk as encapsulating matrix, ensuring bacterial cells viability (above the minimum required threshold) up to one month under common shelf-life conditions. Significance/Impact of the work: This work presents spray-drying using skim milk matrix as a technological solution for delivering the probiotic strain A. muciniphila and this formulation could be promising therapeutic/prevention option in metabolic disorders. Furthermore, this strategy can possibly be extended to other next-generation probiotics and facilitate the incorporation of such probiotic bacteria into food bases, suitable for human consumption.