Protective Effects of Double-layered Multinucleated Microcapsules Containing Bifidobacterium adolescentis FS2-3 Against Enteritis Mediated by Different Pathogens.

Bifidobacterium adolescentis (B. adolescentis), a dominant probiotic in the gut of infants and healthy adults, exerts protective effects on immune development and disease prevention. However, the intervention capability of B. adolescentis against different pathogenic bacteria remains unclear. In this study, we verified that B. adolescentis FS2-3 showed inhibitory effects against five common pathogenic bacteria, including Shigella dysenteriae CMCC 51,252, Klebsiella pneumoniae NCTC 13,440, Pseudomonas aeruginosa CMCC 10,104, Salmonella enteritidis CMCC 50,746, and Campylobacter jejuni CICC 22,936. To improve its intestinal colonization efficiency, we constructed double-layered multinucleated microcapsules (probiotic microcapsules) of B. adolescentis FS2-3 and evaluated their effects on bacterial enteritis induced by five representative foodborne pathogens. The in vitro experiments showed that the survival rate of B. adolescentis FS2-3 in the microcapsules was increased by 5.76 times compared with the unencapsulated strain. Additionally, the probiotic microcapsules significantly reduced intestinal tissue damage and inflammation in all enteritis mice, especially in Salmonella-infected mice. Specifically, the probiotic microcapsules reversed the abnormal bacterial composition by promoting the colonization of beneficial bacteria Bifidobacterium, Alloprevotella, and Lachnospiraceae. Furthermore, the probiotic microcapsules inhibited the overexpression of TLR-4 and reduced the expression of inflammatory mediators, including IL-1β, NF-κB, and TNF-α. These findings provide new insights into the application of probiotic microcapsules in the treatment of enteritis.