Reuterin is an intermediate in the metabolism of glycerol to 1,3-propanediol catalysed by the coenzyme B12-dependent glycerol dehydratase.
Reuterin is a potent antimicrobial compound produced by Lactobacillus reuteri.  It is an intermediate in the metabolism of glycerol to 1,3-propanediol catalysed by the coenzyme B12-dependent diol dehydrase. It inhibits the growth of some harmful Gram-negative and Gram-positive bacteria, along with yeasts, molds, and protozoa. L. reuteri can secrete sufficient amounts of reuterin to inhibit the growth of harmful gut organisms, without killing beneficial gut bacteria, allowing L. reuteri to remove gut invaders while keeping normal gut flora intact.
Reuterin is water-soluble, effective in a wide range of pH, resistant to proteolytic and lipolytic enzymes, and has been studied as a food preservative or auxiliary therapeutic agent.
Reuterin as an extracted compound has been shown capable of killing Escherichia coli O157:H7 and Listeria monocytogenes, with the addition of lactic acid increasing its efficacy.  It has also been demonstrated to kill Escherichia coli O157:H7 when produced by L. reuteri.