Preparation of pinolenic acid-embedded Lactiplantibacillus plantarum H6 Pickering emulsions stabilized with different concentrations of sodium alginate

This study aimed to enhance the gastrointestinal survival of the probiotic Lactiplantibacillus plantarum H6(L.p H6)by developing a protective encapsulation system based on Pickering emulsions. The efficacy of this system in alleviating obesity was subsequently evaluated in high-fat diet (HFD)-fed mice. Pickering emulsions were formulated using pea protein isolate (PP) and sodium alginate (SA) as the aqueous phase. Glucono-delta-lactone (GDL), calcium carbonate (CaCO₃), and pinolenic acid (PLA) were incorporated, followed by high-speed dispersion to produce the final emulsions. Results demonstrated that emulsions containing SA achieved an encapsulation efficiency of up to 91 %(p < 0.05), highlighting their superior capacity for probiotic protection. The absolute zeta potential values of all emulsions exceeded 40 mV, indicating excellent colloidal stability. Laser confocal microscopy revealed a reduction in oil droplet size with increasing SA concentration, attributed to the enhanced aqueous phase viscosity generating stronger shear forces during homogenization. Cryo-electron microscopy (Cryo-EM) further showed that SA-containing emulsions formed a three-dimensional gel network, a spatial configuration offering enhanced protection for the encapsulated probiotics. Animal experiments demonstrated that administration of the Pickering emulsion significantly reduced body weight gain by 6.8 % compared to the high-fat diet (HFD) control group. Furthermore, the emulsion treatment improved inflammatory markers and lipid profiles in obese mice and alleviated fatty liver disease. The Pickering group effectively reduced total serum cholesterol TC (33.3 %), triglyceride TG (3.5 %), and low-density lipoprotein LDL-C (50 %) levels(p < 0.01),while increasing high-density lipoprotein HDL-C (50 %) levels. This study highlights the potential of Picklin emulsion in probiotic delivery and explores the combined benefits of unsaturated fatty acids (PLA) and probiotics. Based on the results of animal model experiments and the synergistic effects observed in vivo, future research should focus on translating the PLA-probiotic synergistic effect into multi-omics-guided functional foods to achieve personalised anti-obesity interventions.