Encapsulation of Lactobacillus plantarum in casein-chitosan microparticles facilitates the arrival to the colon and develops an immunomodulatory effect

• Published in: Food hydrocolloids 2023-03, Vol.136, p.108213, Article 108213
• Main Authors: Peñalva, Rebeca, Martínez-López, Ana Luisa, Gamazo, Carlos, Gonzalez-Navarro, Carlos J., González-Ferrero, Carolina, Virto-Resano, Raquel, Brotons-Canto, Ana, Vitas, Ana Isabel, Collantes, Maria, Peñuelas, Ivan, Irache, Juan M.
• Format: Article
• Language: English
• Subjects: Biodistribution; calcium; Casein; chitosan; colon; cost effectiveness; crosslinking; dietary supplements; encapsulation; hydrocolloids; ileum; immune system; Immunomodulation; immunomodulators; Lactobacillus plantarum; mice; Microparticles; Probiotics; sodium caseinate; spray drying; storage quality; survival rate; tripolyphosphates; vanillin
• ISSN: 0268-005X; 1873-7137
• DOI: 10.1016/j.foodhyd.2022.108213

The current work describes the capability of casein-chitosan microparticles to encapsulate Lactobacillus plantarum (CECT 220 and WCFS1 strains) and evaluates their ability to target the distal areas of the gut and to stimulate the immune system. Microparticles were prepared by complex coacervation, between sodium caseinate and chitosan in an aqueous suspension of the bacteria, and dried by spray-drying. In order to increase the survival rate of the loaded bacteria, microparticles were cross-linked with one of the following cross-linkers: tripolyphosphate, calcium salts or vanillin. Overall, microparticles displayed a mean size of about 7.5 μm with a bacteria loading of about 11 Log CFU/g, when cross-linked with vanillin (MP-LP-V). For conventional microparticles, the payload was 10.12 Log CFU/g. The storage stability study at 25 °C/60% RH, MP-LP-V offered the highest degree of protection without significant modification of the payload in 260 days. Compared with control (aqueous suspension of bacteria), MP-LP-V also displayed a significantly higher degree of protection against probiotic inactivation in simulated gastric and intestinal fluids. In vivo results evidenced that microparticles, orally administered to rats, were able to reach the distal ileum and colon in about 4 h post-administration. Additionally, the effect of the daily administration of 107 CFU/mouse of MP-LP-V, for 3 weeks, induced an immunomodulatory effect characterized by an important enhancement of Th1 and Th17 responses. In conclusion, these microparticles seem to be a promising strategy for increasing survival and efficacy of probiotics, allowing the formulation of cost-effective and more stable and effective probiotic-based nutraceuticals. [Display omitted] •Casein-chitosan microparticles can load up to 11 Log CFU/g of L. plantarum strains.•Microparticles increased survival rate of L. plantarum during storage.•Microparticles offered protection against simulated gastric and intestinal fluids.•Microparticles reached the colon in about 4 h.•Microencapsulated L. plantarum induces an immunomodulatory effect in rats.