Development and characterization of a nano-based synbiotic formulation using Lactiplantibacillus plantarum RJ 2 and inulin

Abstract

Emerging nutraceuticals aim to improve gut health by utilizing probiotics, prebiotics and synbiotics. However, the inherent instability and reduced viability of probiotics necessitate innovative nutraceutical formulations to ensure efficacy. This study reports the development of a synbiotic nano-based formulation by interacting Lactiplantibacillus plantarum RJ 2 with Bovine Serum Albumin (BSA) nanoparticles (BNPs) and subsequently surface functionalizing them with inulin using a sequential deposition assembly strategy. The resulting nano-based formulation functioned as an efficient synbiotic system with improved viability and structural stability. BSA nanoparticles were synthesized through a glutaraldehyde-mediated crosslinking process, yielding monodisperse particles with an average size of 59 nm. Comprehensive physicochemical characterization validated and confirmed the formation of stable BSA nanoparticles (BNPs) with well-defined spherical morphology, consistent particle size distribution, and improved colloidal stability under physiological conditions, attributed to their high negative surface charge. The inulin-functionalized probiotic-BNPs (I.BNPs) exhibited a hydrodynamic diameter of approximately 482 nm with a polydispersity index (PDI) of 0.285, confirming uniform layering and surface hydration. This synbiotic nano-based formulation demonstrated excellent physicochemical stability, high probiotic viability, and enhanced structural uniformity, as validated by different characterization techniques. Under simulated gastrointestinal (GI) conditions, this nano-based formulation achieved a 95% survival rate, demonstrating substantial enhancement in probiotic resistance to acidic and bile environments. By integrating probiotic-interacted BNPs with the prebiotic functionality of inulin, this hybrid system created a dual-acting synbiotic platform that confers both physical protection and nutritional enhancement. The developed inulin-functionalized BNP-based system represents a next-generation synbiotic formulation with potential applications in functional foods, nutraceuticals, and therapeutic probiotic delivery.