Utilizing chitosan and pullulan for the encapsulation of Lactiplantibacillus plantarum ZJ316 to enhance its vitality in the gastrointestinal tract

Lactiplantibacillus plantarum ZJ316 has demonstrated effective alleviation of gastritis and colitis, making it crucial to improve its viability within the gastrointestinal tract. In this study, Chitosan (CS) and pullulan (PUL) encapsulated nanofibers of ZJ316 were prepared using electrospinning, considering both the synergistic effects of prebiotics and probiotics and their protective effects. We found that increasing the CS ratio resulted in elevated conductivity of the polymer solution, while decreasing viscosity and pH. Scanning electron microscopy showed that at a CS: PUL ratio of 1:135, polymer filaments were difficult to form, and nanofiber diameter decreased with higher CS content. X-ray diffraction analysis confirmed the miscibility of CS and PUL, while ATR-FTIR demonstrated the presence of hydrogen bonding interactions between the two materials. Thermal analysis indicated that an increased CS concentration improved the thermal stability of the nanofibers. Based on these findings, the optimal CS:PUL ratio for electrospinning was determined to be 1:60. Encapsulation of ZJ316 in the nanofibers significantly enhanced its survival rate in simulated gastrointestinal fluid compared to free bacteria, with survival rates of 87.24 % (gastric) and 79.71 % (intestinal), respectively. This study provides valuable insights for the development of probiotic functional foods.