Synthesis and Application of Encapsulated Bifidobacterium longum for Mitigation of Liver Fibrosis via Modulation of Oxidative Stress and Inflammation in a BDL Rat Model

Liver fibrosis is a progressive disorder with limited therapeutic options. Probiotics, particularly Bifidobacterium longum (B. longum), represent a promising microbial biotechnology approach for hepatoprotection; however, their clinical efficacy is often compromised by low gastrointestinal survival. In this study, we evaluated the effects of B. longum encapsulated in a food-grade alginate–whey protein matrix with a chitosan coating to enhance microbial stability and delivery, and its impact on liver fibrosis in a bile duct ligation (BDL) rat model. Forty-eight male Wistar rats were assigned to six groups, including controls, BDL, and BDL treated with free or encapsulated probiotics. Encapsulation substantially improved probiotic viability under simulated gastric conditions (log 9.6 vs. 3.5) and effectively reduced serum markers of liver injury (ALT, AST, LDH). Encapsulated B. longum also modulated inflammatory mediators (downregulating IL-6, TNF-α, α-SMA; upregulating IL-10), enhanced antioxidant defenses, decreased oxidative stress markers, and attenuated histological liver damage. These findings highlight encapsulation as a microbial biotechnology strategy to optimize probiotic delivery and efficacy, supporting their therapeutic potential in liver fibrosis.