Encapsulation of probiotics: insights into academic and industrial approaches

The natural inhabitants of the gastrointestinal tract play a key role in the maintenance of human health. Over the last century, the changes on the behavior of our modern society have impacted the diversity of this gut microbiome. Among the strategies to restore gut microbial homeostasis, the use of probiotics has received a lot of attention. Probiotics are living microorganisms that promote the host health when administered in adequate amounts. Its popularity increase in the marketplace in the last decade draws the interest of scientists in finding suitable methods capable of delivering adequate amounts of viable cells into the gastrointestinal tract. Encapsulation comes into the scene as an approach to enhance the cells survival during processing, storage and consumption.This paper provides a comprehensive perspective of the probiotic field at present time focusing on the academia and industry scenarios in the past few years in terms of encapsulation technologies employed and research insights including patents. The analysis of the encapsulation technologies considering food processing costs and payload of viable bacteria reaching the gastrointestinal tract would result into successful market novelties. There is yet a necessity to bridge the gap between academia and industry

Original behavior of L-rhamnosus GG encapsulated in freeze-dried alginate-silica microparticles revealed under simulated gastrointestinal conditions

The probiotic bacteria L. rhamnosus GG (LGG) were encapsulated into core-shell alginate-silica microbeads of about 500 mm through a double step synthesis involving micro-ionogel formation by electrospraying and silica coating by the sol-gel process. Formulating microparticles with sucrose as a cryoprotectant allowed maintaining bacterial viability and cultivability upon freeze-drying for weeks, as determined by plate counting. As much as 3.4 x 10(10) CFU g(-1) and 4.1 x 10(8) CFU g(-1) were observed to be cultivable in alginate and silica-coated beads after 3 weeks of freeze-drying, respectively. The viability of the released bacteria was evaluated in an in vitro batch SHIME model (a simulator of the human intestinal microbial ecosystem) by denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR). It was revealed that microencapsulation efficiently protects LGG from the low gastric pH, especially in the case of silica-coated beads. Both encapsulation systems (alginate and alginate-silica) allowed for a better colonization of the colon compared with free LGG. Interestingly, although metabolically inactive in the upper digestive tract, LGG released from silica-coated beads boost their metabolism once they arrive in the colon, where they outcompete other members from the Lactobacillus community. In view of these results, we show that silica, usually used as an anti-caking agent in food powders, can play an active role in probiotics delivery and colon colonization