A novel role for Magnetotactic bacterium: Magnetospirillum magneticum AMB-1 prolonged healthy lifespan of Caenorhabditis elegans via regulating ferroptosis.

Magnetotactic bacteria (MTB), which contain special nano-magnetic particles within their cells, have been extensively studied for biomedical applications including drug delivery and cancer treatment. However, the practical application of bacteria themselves remains relatively limited in current research. Magnetospirillum magneticum AMB-1 (AMB-1), an MTB capable of iron biomineralization and possessing potential antioxidant properties, was investigated in this study for its effects on lifespan and healthspan in Caenorhabditis elegans (C. elegans), as well as its underlying mechanisms. Our results showed that feeding with AMB-1 significantly extended the mean lifespan of C. elegans by 43.4% ± 13.4%, from 17.17 ± 1.25 to 24.62 ± 1.44 days. Moreover, AMB-1 improved neural function and preserved intestinal integrity in aged C. elegans, leading to a significant healthy lifespan extension. Further research found that AMB-1 treatment decreased Fe2+ content by 34.11% ± 14.96% and lipid peroxide levels by 52.19% ± 7.56%, compared to the OP50-fed control. Notably, AMB-1 administration markedly attenuated aging-associated ferroptosis. Specifically, AMB-1 upregulated the expression of ftn-1, which encodes ferritin, and downregulated bli-3, the sole NADPH oxidase (NOX) homolog that promotes ferroptosis in C. elegans, leading to suppression of ferroptosis-related indicators. RNA interference (RNAi) experiments revealed that the ferroptosis-related gene ads-1, encoding alkylglycerophosphate synthase (AGPS), played a critical role in AMB-1-induced longevity. These findings demonstrated that AMB-1 promoted healthy aging in C. elegans by inhibiting ferroptosis, highlighting its potential as an effective anti-aging microbial agent.