The efficacy of three double-microencapsulation methods for preservation of probiotic bacteria

Lactic acid bacteria (LAB) are used as a probiotic alternative to antibiotics in livestock production. Microencapsulation technology is widely used for probiotic preservation. A variety of microencapsulation protocols have been proposed and compared based on chemicals and mechanical procedures. This study aimed to develop a double-encapsulated coating from alginate (1.5%) and chitosan (0.5%) by extrusion, emulsion, and spray drying methods using the LAB strains Lactobacillus plantarum strains 31F, 25F, 22F, Pediococcus pentosaceus 77F, and P. acidilactici 72N, and to monitor the basic probiotic properties of the encapsulated prototypes. The final products from each microencapsulation protocol were analysed for their appearance, probiotic properties and viable cell count. Using the spray drying method, particles smaller than 15 μm in diameter with a regular spherical shape were obtained, whereas the other methods produced larger (1.4–52 mm) and irregularly shaped microcapsules. After storage for 6 months at room temperature, the LAB viability of the spray-dried particles was the highest among the three methods. In all the LAB strains examined, the encapsulated LAB retained their probiotic properties in relation to acid-bile tolerance and antibacterial activity. This study highlights the efficacy of double-coating microencapsulation for preserving LAB properties and survival rate, and demonstrates its potential for probiotic application in livestock farms

Microencapsulated probiotic Lactiplantibacillus plantarum and/or Pediococcus acidilactici strains ameliorate diarrhoea in piglets challenged with enterotoxigenic Escherichia coli

Lactiplantibacillus plantarum (strains 22F and 25F) and Pediococcus acidilactici (strain 72N) have displayed antibacterial activity in vitro, suggesting that they could be used to support intestinal health in pigs. The aim of this study was to determine if microencapsulated probiotics could reduce the severity of infection with enterotoxigenic Escherichia coli (ETEC) in weaned pigs. Sixty healthy neonatal piglets were cross-fostered and separated into five groups. Piglets to be given the microencapsulated probiotics received these orally on days 0, 3, 6, 9, and 12. Only piglets in groups 1 and 5 did not receive probiotics: those in groups 2 and 4 received the three microencapsulated probiotic strains (multi-strain probiotic), and piglets in group 3 received microencapsulated P. acidilactici strain 72N. After weaning, the pigs in groups 3-5 were challenged with 5 mL (at 109 CFU/mL) of pathogenic ETEC strain L3.2 carrying the k88, staP, and stb virulence genes. The multi-strain probiotic enhanced the average daily gain (ADG) and feed conversion ratio (FCR) of weaned piglets after the ETEC challenge (group 4), whilst supplementing with the single-strain probiotic increased FCR (group 3). Piglets in groups 3 and 4 developed mild to moderate diarrhoea and fever. In the probiotic-fed piglets there was an increase in lactic acid bacteria count and a decrease in E. coli count in the faeces. By using real-time PCR, virulence genes were detected at lower levels in the faeces of pigs that had received the probiotic strains. Using the MILLIPLEX MAP assay, probiotic supplementation was shown to reduce pro-inflammatory cytokines (IL-1α, IL-6, IL-8, and TNFα), while group 4 had high levels of anti-inflammatory cytokine (IL-10). Challenged piglets receiving probiotics had milder intestinal lesions with better morphology, including greater villous heights and villous height per crypt depth ratios, than pigs just receiving ETEC. In conclusion, prophylactic administration of microencapsulated probiotic strains may improve outcomes in weaned pigs with colibacillosis