Multi-Model Longevity Assays Reveal Lifespan- and Healthspan-Promoting Effects of Bacillus subtilis WTC019

Bacillus subtilis is a spore-forming probiotic with an established safety profile, yet its effects on aging-related phenotypes remain incompletely defined. Here, we assessed the lifespan- and healthspan-promoting activity of a novel strain, B. subtilis WTC019, using integrated invertebrate, cellular, and mammalian aging models. In Caenorhabditis elegans, B. subtilis WTC019 significantly extended lifespan, increasing median lifespan by 17.48%, 90% lifespan by 35.36%, and maximum lifespan by 19.07%, and attenuated age-associated locomotor decline. In human skin fibroblasts, B. subtilis WTC019 cell lysate reduced senescence-associated β-galactosidase activity by approximately 34% and altered cell cycle distribution consistent with delayed cellular senescence. Moreover, dietary supplementation with B. subtilis WTC019 significantly prolonged lifespan in C57BL/6J mice, with median lifespan increases of 5.97% in females and 6.05% in males. Together, these results demonstrate that B. subtilis WTC019 promotes lifespan- and healthspan-associated phenotypes across multiple aging models, supporting its potential as a probiotic candidate for healthy aging interventions.