<i>Bacillus amyloliquefaciens</i> WF2020 isolated from fermented pickles promotes longevity and health in <i>Caenorhabditis elegans via</i> JNK and p38 MAPK pathways

<i>Bacillus amyloliquefaciens</i>, a potential probiotic for use in food and feed production, can exert anti-aging effects in a strain-specific manner. However, the molecular mechanisms underlying its anti-aging effects remain poorly understood. This study explored the effects of <i>B. amyloliquefaciens</i> WF2020 (WF2020), isolated from Chinese fermented pickles, on longevity and health and investigated the underlying mechanisms in <i>Caenorhabditis elegans</i>. Interestingly, WF2020 was found to increase mean lifespan, worm length, body bends, and resistance to heat, oxidative stress, and <i>Staphylococcus aureus</i> infection. It also improved mitochondrial transmembrane potential and antioxidative status, reduced lipid accumulation and oxidative damage, and altered the expression of several genes involved in cell apoptosis, fat metabolism, host tolerance to heat and oxidative stress, and immune responses, compared to <i>Escherichia coli</i> OP50 (OP50), a standard food source for <i>C. elegans</i>. Moreover, WF2020-fed loss-of-function mutants for <i>nsy-1</i>, <i>sek-1</i>, <i>pmk-1</i>, <i>jkk-1</i>, <i>jnk-1</i>, <i>daf-16</i>, and <i>hsf-1</i> did not exhibit lifespan extension. Additionally, WF2020-fed <i>pmk-1</i> and <i>jnk-1</i> mutants showed similar worm length, body bends, lipid accumulation, mitochondrial transmembrane potential, and antioxidative properties to the OP50 group. Correspondingly, WF2020 significantly upregulated the expression of <i>nsy-1</i>, <i>sek-1</i>, <i>pmk-1</i>, <i>jkk-1</i>, and <i>jnk-1</i> and increased the proportion of DAF-16::GFP in the nucleus, along with the expression of HSP-16.2::GFP. In conclusion, WF2020 activated the p38 MAPK and JNK pathways to regulate the functions of HSF-1 and DAF-16, thereby promoting longevity and health in <i>C. elegans</i>. These findings suggest that WF2020 could be a potential probiotic or a starter for use in food and feed production to delay aging and promote health.