Due to their low acid tolerance, a majority of probiotics face diculties with regard tosurviving in the gastric environment long enough to reach the intestinal surfaces where they colonizeand provide health benefits. We prepared a probiotic delivery system that can enhance their viabilityin acidic conditions by developing a one-step poly-L-lysine (PLL) coating process. We determinedwhether the coating process was successful by measuring the zeta potential and observing it withconfocal scanning microscopy. PLL-coated L. plantarum (PLL-LP), incubated in a solution of pH 2 for2 h, exhibited a higher viability (6.86 0.12 log CFU/mL of viable cells) than non-coated L. plantarum(non-coated LP), which exhibited only 2.7 1.23 log CFU/mL of viable cells. In addition, a higheramount of L. plantarum was detected in the feces of mice orally administered PLL-LP (6.2 0.4 logCFU/g of feces) than in the feces of the control groups. In addition to enhancing probiotic viability inpH 2 solution, the PLL coating showed no eect on the probiotic growth pattern and the viability ofeither freeze-dried L. plantarum or L. plantarum, stored at ?20 C and 4 C, respectively. Overall, theseresults indicated that the PLL coating is a promising potential probiotic delivery system.
Keywords: Lactobacillus plantarum; acid resistance; poly-L-lysine; probiotics; viability.