Dietary quinic acid supplied as the nutritional supplement AIO + AC-11® leads to induction of micromolar levels of nicotinamide and tryptophan in the urine.

Hippuric acid is synthesized and produced primarily by the gastrointestinal (GI) microflora. However, there is no known health benefit for hippuric acid except its catabolic conjugation of benzene-type compounds via glycine and subsequent excretion in the urine. For years the GI tract microflora were known to metabolize quinic acid to hippuric acid. Recently it was also proposed that DNA repair was strongly enhanced by quinic acid. In order to explain these quinic acid effects, Pero and colleagues have examined whether tryptophan and nicotinamide were also enhanced by quinic acid levels in urine. They were indeed, and so another study was designed using a natural supplement source of quinic acid called AIO + AC-11®, and then the effects of intervention were measured after only 21 days. It was possible to show profound increases in quinic acid that were again paralleled by increases in tryptophan and nicotinamide urinary levels. Because the high pressure liquid chromatography (HPLC) methods differed greatly between the two studies, differences in chemical analyses probably did not contribute to the data base.