Indole-3-carboxaldehyde is an endogenous metabolite of plants and is produced in humans by the metabolism of L-tryptophan in Lactobacillus and other gastrointestinal bacteria. Indole-3-carboxaldehyde is an immunomodulator, acting as an agonist of the aryl hydrocarbon receptor in human intestinal immune cells, stimulating the production of interleukin-22. Indole-3-carboxaldehyde contributes to plant defenses against phytopathogenic fungi and modulates the quorum sensing pathway in V. parahaemolyticus in vitro to reduce biofilm formation. Indole-3-carboxaldehyde can be used as a biomarker for cardiometabolic risk in humans.
