Effects and mechanisms of lifespan extension and healthspan promotion induced by Limosilactobacillus reuteri (Lactobacillus reuteri) A21041

Background Nowadays probiotics have been widely used in the fields of food, medicine and agriculture. In this study, we investigated the anti-aging effects of the probiotic strain of Limosilactobacillus reuteri A21041 using Caenorhabditis elegans . Methods In this study, lifespan assays, lipid storage experiments, motility tests and stress resistance assays were conducted using C. elegans to present the differences between A21041 and control group Escherichia coli OP50. Besides, transcriptome sequencing and non-targeted metabolomics analysis were performed to further reveal the mechanism of A21041-mediated lifespan prolongation. Results We found that A21041 extended the lifespan of nematodes by 19.27% compared with the control group, and reduced lipid accumulation of C. elegans by 54.47% in day 5 and 68.77% in day 7 via lysosome signaling pathway. In addition, A21041 increased the viability of worms under thermal stimulus through up-regulation of hsp-16.2 and hsp-110 mRNA levels. Meanwhile, A21041 feeding activated superoxide dismutase (SOD) and enhanced antioxidative ability of nematodes. Of impoatance, A21041 did not extend the lifespan of loss-in function mutants of daf-2 , akt-2 and aak-2 , which suggested that insulin/IGF-1 signaling (IIS) were required for the life-extending effect of A21041. RNA-seq analysis was consistent with our findings above. Gene gst-4 , which has been confirmed to be highly associated with antioxidant activity and lifespan extension was significantly up-regulated. And RNA sequencing still revealed that ATF-4/CTH-2/H2S pathway might be related to A21041-mediated longevity. Metabolites analysis presented that many metabolites produced by A21041 could protect worms from various damages such as oxidants, inflammatory factors and etc. Conclusion In conclusion, our results demonstrated that L. reuteri A21041 was able to prolong the lifespan and promote the healthspan(definition) of Caenorhabditis elegans .