There existed a deficiency in the research on the nutritional activities of microbial (yeast) active substances in antioxidant and anti-aging activities, although the research objects were concentrated in animals and plants in recent years. In this study, the anti-oxidant and anti-aging activities of protein-rich yeast extract (®fermgard) (YE) were investigated through Caenorhabditis elegans (C. elegans). The results indicated that YE could improve the lifespan and anti-stress ability by up-regulating the activities of antioxidant enzymes in C. elegans. Meanwhile, the mRNA transcriptional level of
daf-16,
skn-1 and
sod-3 was significantly up-regulated. In addition, the composition and level of the gut microbiota and metabolite were modulated. YE exerts antioxidant and anti-aging activities by regulating the expression of anti-oxidation-related mRNA, gut microbiota and metabolites in C. elegans, providing a basis for exploring the deep mechanism of YE improving health. At the same time, it provides new ideas for the development of functional foods.