Shield-armed probiotic delivery system based on co-deposition of poly-dopamine and poly-l-lysine helps Lactiplantibacillus plantarum relieve hyperuricemia

Hyperuricemia (HUA) is a disease characterized by an abnormal metabolism of purine. Lactic acid bacteria (LAB) have attracted much attention for their safe and effective treatment of HUA by inhibiting xanthine oxidase (XOD) and regulating gut microbiota. However, the effectiveness of probiotics can be compromised by the harsh environment of the gastrointestinal tract. In preliminary experiments, Lactiplantibacillus plantarum DY1, which is generally regarded as safe (GRAS), can lower uric acid. We have devised a straightforward and efficient technique for encapsulating DY1 using a coating comprising polydopamine (PDA) co-deposited with poly-l-lysine (PLL) to obtain DY1@PDLL. TEM, SEM, FT-IR and DLS tests showed that DY1 was successfully coated. Incubate at SGF or SIF for 3 h, the number of viable bacteria of free probiotics and DY1@PDLL decreased by 0.92 and 0.46 log cfu/mL, 1.66 and 0.66 log cfu/mL, respectively. The fluorescence intensity of the intestines of the DY1@PDLL treated mice was 3.96 times that of free probiotic. Notably, DY1@PDLL can reduce the uric acid levels of HUA mice by 31.63 % and free probiotics by 18.72 % (≈1.69 times). DY1@PDLL could also regulate gut microbiota and serum metabolic profile. These findings unequivocally highlight the remarkable potential of DY1@PDLL as an exceptional oral probiotic delivery system.