Absorption of Biological Amines of Bacterial Origin in Normal and Sick Infants

: This investigation aims at monitoring the formation of diamines in the gastrointestinal tract of human infants, and thereby also the bacterial colonization of the intestine, by studying the urinary excretion of the heterocyclic amine piperidine during development and in different malabsorptive states. A gas chromatographic assay of the dinitrophenyl derivative of piperidine and a mass spectrometric method of identification were worked out and applied. The piperidine excretion was expressed in units of urinary creatinine concentration. Adult women show a greater variation than men, both inter- and intra-individually. The piperidine excretion is very low and mostly undetectable in the first week of life. There is an increase in weaning, with a significant difference between breast-fed and formula-fed infants at 4--6 months. There is a significant difference between infants suffering from untreated coeliac disease and infants without malabsorption. The findings indicate that piperidine excretion is a sensitive biochemical index of changes in the gastrointestinal flora. The high excretion in coeliac disease suggests that piperidine, which is known to have nicotine-like synaptic activity in the CNS, is one of the hitherto unidentified 'auto-intoxicating' substances arising from the bacterial decomposition of protein suggested by Metchnikoff in 1903.