Abstract: The activity of probiotic products would reduce to a certain extent during storage and in the gastrointestinal tract, resulting in weakened potential probiotic properties, in this study, Lactobacillus fermentum LTP1332 from the feces of centenarians in Bama, Guangxi was microencapsulated. In this experiment, gelatin (GEL) and chitosan (CS) were introduced for compounding based on sodium alginate (SA) and CaCl₂ as the main wall materials. The key factors affecting the embedding rate were found by single-factor test, the radial basis function (RBF) was constructed by using Box-Behnken design (BBD), and the encapsulation process of Lactobacillus fermentum LTP1332 microcapsules was optimized by using genetic algorithms (GA). The optimized capsules were characterized using SEM scanning electron microscopy and other methods, and the in vitro simulated digestion tests was carried out. Results showed that, the optimum preparation parameters of the microcapsule were as follows: 2.210% sodium alginate, 4.451% CaCl₂, 0.1% gelatin, 13.529 min curing time. Under such conditions, the measured average embedding rate was 95.08%±0.25%. The cell survival rate of CS-GEL-SA microcapsule under the optimized processing conditions could still reach 22.48%±0.78% after being treated with simulated gastric juice for 120 min. The maximum rate of probiotic release could be reached at 90 min of digestion with simulated intestinal juice, which had good intestinal solubility. Therefore, it is considered that the long-lived elderly source probiotic microcapsule prepared under this processing condition would have a good bacterial protection effect and good prospects in development and application.