What is spermidine and where is it found?

Spermidine is a small, nitrogen-rich molecule that occurs naturally in virtually all living organisms: from yeast and worms to humans. The body produces spermidine itself, but it is also absorbed through food and produced by gut bacteria.

A large proportion of the spermidine in your body comes from the gut. Bacteria in the gut produce polyamines during the breakdown of proteins, including putrescine as an intermediate step, which is then converted into spermidine. The gut is therefore one of the most important sources for the body.

Spermidine is also found in ordinary foods. Products that have been fermented or aged generally contain more spermidine. Population research shows that a higher dietary intake is associated with lower mortality, although this is an association and not yet proof of cause and effect.

One striking characteristic: spermidine levels in the body decline as you get older. Whether this declining level actually contributes to ageing has not been firmly established in humans. Something else researchers describe: spermidine activates the same cellular clean-up system that fasting does, which is why it has earned the nickname 'fasting mimetic'.