Researchers at Osaka Metropolitan University found that familiar and affordable foods can help create a society where people are healthier and less stressed.
Japanese natto, which is made from softened soybeans that have been boiled or steam-fermented with a bacteria known as Bacillus subtilis var. natto, might be one example of such a food.
The study was published in the journal, ‘Journal of Applied Microbiology’. The human stomach and intestines contain Bacillus subtilis var. natto, as do plants, animals, and soil. The miyagino strain is used to produce the majority of the natto consumed in Japan.
The lifespan of the host was examined using Caenorhabditis elegans worms by a research team at the Graduate School of Human Life and Ecology, under the direction of Professor Eriko Kage-Nakadai.
The researchers found that Caenorhabditis elegans fed Bacillus subtilis var. natto had a significantly longer lifespan than those fed the standard diet, and further elucidated that the p38 MAPK pathway and insulin/IGF-1-like signalling pathway, which are known to be involved in innate immunity and lifespan, were involved in the lifespan-enhancing effects of Bacillus subtilis var. natto. They also examined stress tolerance, which has been shown to have a correlation with longevity, and found that resistance to UV light and oxidative stress is enhanced.
Professor Nakadai concluded, “For the first time, we were able to demonstrate the possibility of lifespan-extending effects of Caenorhabditis elegans through the ingestion of Bacillus subtilis var. natto. We hope that future experiments on mammals and epidemiological studies will help to realise a healthy and longer-living society if we can apply this research to humans.