Targeted release of live probiotics from alginate-based nanofibers in a simulated gastrointestinal tract

Abstract

Gut bacteria influence human health by digesting nutrients, modulating immune responses, and communicating with the nervous system. Orally delivered probiotics must survive the harsh environment of stomach acid to reach the gut microbiome and incur a health benefit. Here, the probiotic Lactococcus lactis was encapsulated via coaxial electrospinning into alginate-based nanofibers containing the antacid calcium carbonate. Though the high molecular weight polyethylene oxide was used to facilitate fiber formation, crosslinking the nanofibers in an aqueous solution allowed the polyethylene oxide to diffuse out of the nanofiber to form a safe for oral consumption formulation. The antacid protected the encapsulated living bacteria against acidic insults; thus, bacteria remained viable and encapsulated during submersion in a simulated stomach model. After transfer to the intestinal phase, up to 120 000 viable probiotic cells were released per gram of nanofibers demonstrating the pH-dependent delivery of the electrospun alginate nanofibers.