Microencapsulation of Bacillus smithii XY1 by spray drying and evaluation for treatment of inflammatory bowel disease

Microencapsulation is a promising and feasible method to help probiotics against adverse situation and overcome storage instability. In this study, we prepared Bacillus smithii XY1 microcapsules by spray drying. Firstly, wall materials of the microcapsules were screened and the ratio between wall materials and protective agent was optimized. The results showed that 9% gum arabic and 5% soluble starch along with 4% skim milk powder were the best condition for spray drying through response surface method . Through scanning electron microscope (SEM), bacteria were successfully encapsuled in the wall materials and microcapsules presented complete structure without cracks. Compared to non-encapsulated bacteria, encapsulation increased tolerance of B. smithii XY1 in gastrointestinal environment, improved shelf time and showed a better effect on alleviating intestine inflammation of zebrafish induced by dextran dulfate sodium (DSS). Thus, this encapsulation approach may have the potential application for improving efficacy of B. smithii XY1 and other probiotics.