Research

Mixed

Dietary polyamines (spermidine, spermine, putrescine) are absorbed from the gut, and prolonged oral supplementation increases blood levels of these polyamines in both animal and human subjects.

Eating foods rich in polyamines, such as natto (fermented soy), can increase the levels of spermine in your blood. This absorption is efficient, with a significant portion of ingested polyamines entering the bloodstream. While this confirms bioavailability, it does not automatically guarantee metabolic health benefits without further context.

GoodSupportsHIGH confidence
In mouse models, prolonged administration of polyamine-rich diets have been seen to increase blood levels of spermidine and/or spermine... In humans it has been shown that a prolonged intake (2 months) of polyamine-rich products such as natto (fermented soy) produces a significant rise in the levels of spermine (but not spermidine) in blood
Bruno Ramos‐Molina et al. · Frontiers in Nutrition · 2019

Why this rating

Supported by multiple studies in mice and humans showing increased blood levels with dietary intake.

Source

Dietary and Gut Microbiota Polyamines in Obesity- and Age-Related Diseases

Bruno Ramos‐Molina et al. · Frontiers in Nutrition · 2019

DOI 10.3389/fnut.2019.00024

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DOI resolved against Crossref · corpus check 2026-06-10

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