Data published in Frontiers in Nutrition also indicated that Limosilactobacillus reuteri strain A21041 was associated with a 70% reduction in fat accumulation in the worms after seven days, compared with the control group. Fat accumulation has been reported to improve the clearing and recycling of old cellular material (autophagy).
“L. reuteri A21041 treatment could significantly extend the lifespan and healthspan of C. elegans,” wrote scientists from AIage Longevity Science Corporation Ltd. and the Guangxi Academy of Sciences. “Additionally, A21041 has been shown to have a strong survival ability in artificial gastrointestinal fluids and bile salts based on our previous studies. Therefore, A21041 could be a promising probiotic in dietary supplements.”
The microbiome and longevity
The study adds to a small but growing body of science exploring how the microbiota and microbiome of long-lived humans may hold some key to healthy aging and longevity.
Multiple studies report that the distinct set of gut microbes in centenarians may contribute to longevity, and that the microbiome of many long-lived people trends towards a more youthful profile.
Indeed, analysis of the microbiome of Maria Branyas, who passed away in 2024 at the age of 117, revealed a profile reminiscent of a much younger adult, which higher abundance of beneficial Bifidobacterium and lower levels of pro-inflammatory Clostridium bacteria. Researchers linked this to her daily consumption of yogurt and adherence to a Mediterranean diet (Cell Reports Medicine, 2025).
These associations have led to researchers attempting to mine the microbiome of centenarians for probiotic candidates to promote healthspan. In 2023, researchers from Nanchang University reported that a combination of four strains isolated from a centenarian could reduce inflammation in the intestine and the brain and improve memory and motor function in aging mice.
The new study focused on a single probiotic strain, Limosilactobacillus reuteri strain A21041, which was isolated from the feces of a healthy centenarian from Beihai City, China.
Study details
The China-based scientists incubated C. elegams with either L. reuteri A21041 or Escherichia coli OP50 (control group). E. coli OP50 is a non-pathogenic strain that is commonly used as a nematode food source in laboratory.
The result showed that the lifespan of nematodes in the A21041 group was 19.3% longer, compared with the control group. Additionally, lipid accumulation decreased by 55% and 69% after five and seven days, respectively, in the probiotic group.
L. reuteri A21041 was found to activate the antioxidant enzyme superoxide dismutase (SOD), leading to enhanced antioxidative ability of the worms.
The researchers also found significant up-regulation of the gene gst-4, which is strongly linked to antioxidant activity and lifespan extension.
Metabolomic analysis revealed that A21041 enriched for a range of metabolites, such as spectinomycin (which confers broad-spectrum antibiotic activity), deoxycholic acid (linked to fat reduction), and syringic acid (alleviates oxidative stress and inflammation, and promotes SOD activity).
The probiotic was also associated with lower arachidonic acid, linoleic acid, and proinflammatory factors, compared to the control group.
“In conclusion, our results demonstrated that L. reuteri A21041 was able to prolong the lifespan and promote the healthspan of Caenorhabditis elegans,” wrote the researchers.
Authors: Frontiers in Nutrition, 2026, Volume 13, doi: 10.3389/fnut.2026.1852156. “Effects and mechanisms of lifespan extension and healthspan promotion induced by Limosilactobacillus reuteri (Lactobacillus reuteri) A21041”. Authors: L. Meng, et al.
