Parasites & Your Brain Parasites, Immune Activation, and the Kynurenine Shift When discussing parasites and chronic symptoms, most conversations focus on nutrient depletion or gut irritation. However, one lesser-known mechanism involves immune-driven changes in amino acid metabolism. During certain infections — including parasitic infections — the immune system activates an enzyme called indoleamine 2,3-dioxygenase (IDO). IDO plays a central role in regulating immune response
