Engineering a hierarchical petaloid mineral shield via polyphenol-mediated mineralization for oral probiotic delivery

Oral delivery of probiotics is fundamentally constrained by the trade-off between gastrointestinal protection and therapeutic activity at inflamed intestinal sites. Here, we report a polyphenol-regulated mineralization strategy that programs a hierarchical petaloid mineral shield on probiotic surfaces through a mild one-pot process. Epigallocatechin gallate (EGCG) directed calcium phosphate assembly into a stacked petaloid shield on Limosilactobacillus reuteri , providing protection during fabrication and gastrointestinal transit while preserving bacterial proliferative capacity. The petaloid shield also enabled immobilization of hyaluronic acid and enhanced retention at inflamed intestinal sites. Partial shield disintegration released EGCG for reactive oxygen species scavenging and local microenvironment modulation alongside liberated probiotics. In a dextran sulfate sodium–induced colitis model, the engineered probiotics reduced disease activity, attenuated inflammatory responses, repaired intestinal barrier integrity, and improved gut microbiota homeostasis. This work provides a polyphenol-regulated mineralization strategy to engineer multifunctional probiotic shields for oral delivery of living therapeutics.