Spermidine is an aliphatic amine that is formed through gut microbial metabolism from the amino acid arginine which is acquired from foods that are high in protein. After being transported into gut microbes, arginine undergoes 2 reactions with the enzymes Arginase and Ornithine Decarboxylase to first form the polyamine putrescine. Then putrescine undergoes a further reaction involving the enzyme spermidine synthase to form spermidine. Like other polyamines, spermidine can also be obtained directly from diet as well. While spermidine can be beneficial and act as a scavenger of reactive oxygen species protecting DNA from oxidative damage, at high levels it is also a protein bound uremic toxin found in the body that can inhibit erythropoietin production eventually leading to anemia.

Metabolism and Physiological Effects of Spermidine References