Mutualistic symbiosis between coated probiotics and astaxanthin liposomes conferred extreme resilience against oxidative stress

Conventional co-delivery systems often fail to survive in harsh physiological environments due to the lack of underlying mechanistic synergy. Inspired by natural symbiotic paradigms, this study evaluated a mutualistic assembly combining astaxanthin liposomes (AL) with coated probiotics (CP) to investigate their defensive behaviors under hydrogen peroxide–induced oxidative stress. In oxidative stress models, this system exhibited robust phenotypic protection, significantly preserving probiotic viability and mitigating biomolecular and structural damage, as evidenced by reduced membrane lipid peroxidation, protein carbonylation, and lactate dehydrogenase leakage. Interfacial thermodynamic and spectroscopic analyses confirmed that an oxidative stress-induced entropy-dominated mode dictated the dynamic enrichment and stable anchoring of AL on the bacterial surface, which in turn facilitated the localized antioxidant action of astaxanthin to efficiently neutralize destructive reactive oxygen species including hydroxyl radicals. Furthermore, high–resolution mass spectrometry elucidated the bidirectional synergistic defense characteristics of this mutualistic symbiotic system, demonstrating that by establishing a balanced network of oxidative interception and microenvironmental chemical shielding, the components jointly constructed a highly resilient assembly. Taken together, this study provided robust theoretical and strategic support for the development of advanced probiotic delivery platforms with exceptional environmental resilience.