IDO (indoleamine 2,3-dioxygenase) activity indicates the rate at which the amino acid tryptophan is metabolised into kynurenine. This pathway is regulated by immune and inflammatory signals, especially cytokines like interferon-γ. Elevated IDO activity (manifested as a low tryptophan/kynurenine ratio) may signify immune activation, chronic inflammation, or oxidative stress. Balanced IDO activity reflects normal immune regulation and sufficient tryptophan availability for the synthesis of serotonin and melatonin.
IDO (indoleamine 2,3-dioxygenase) activity indicates how actively the amino acid tryptophan is converted into kynurenine. This pathway is closely associated with immune regulation and inflammation, as it is triggered by cytokines such as interferon-γ.
Higher IDO activity (indicated by a lower tryptophan/kynurenine ratio) may signify immune system activation, persistent inflammation, infection, or oxidative stress. This implies that tryptophan is being rerouted from serotonin production to immune-related metabolic processes.
Low IDO activity (a higher tryptophan/kynurenine ratio) may indicate decreased immune activation or reduced inflammatory signaling. It can also imply sufficient tryptophan availability for serotonin and melatonin synthesis.
Supporting balanced immune and inflammatory function is essential. Adequate antioxidant intake, stress management, and maintaining healthy gut and immune function can help normalize IDO activity. Ensuring sufficient dietary tryptophan alongside cofactors such as B vitamins and magnesium promotes optimal tryptophan metabolism.