Caenorhabditis elegans （C. elegans） was used as an animal model to study the effect of （-）-5-hydroxy-equol, a microbialmetabolite of isoflavone genistein, on the lifespan, fecundity and resistance against thermal and oxidative stress. The resultsshowed that （-）-5-hydroxy-equol not only significantly increased the lifespan of C. elegans but also significantly enhancedthe resistance against thermal and oxidative stress at the concentrations of 0.1 mmol/L and 0.2 mmol/L. However, the fecundityof C. elegans was not obviously influenced after being exposed to the same concentrations of （-）-5-hydroxy-equol. Further studieson comparative transcriptome analyses and the lifespan ofdaf-16 （mu86） mutant and daf-2 （e1370） mutant indicated that（-）-5-hydroxy-equol prolonged the lifespan of C. elegans through DAF-2/DAF-16 Insulin/IGF-1 signaling pathway. This isthe first report that （-）-5-hydroxy-equol was able to increase the lifespan and improve the thermal and oxidative stress toleranceof C. elegans.
