Histamine Intolerance Test

Histamine is a bioactive molecule that functions as an important neurotransmitter and inflammatory mediator. Histamine intolerance occurs when there is an imbalance between histamine accumulation and the body’s ability to break it down. Histamine intolerance is mainly caused by low levels of an enzyme called DAO. This enzyme helps break down histamine in the digestive system. When there isn’t enough DAO, histamine builds up and causes symptoms. Some individuals inherit genetic variations that reduce their ability to produce adequate amounts of DAO enzyme or affect how efficiently the enzyme functions. Conditions such as SIBO (small intestinal bacterial overgrowth), IBS (irritable bowel syndrome), IBD (inflammatory bowel disease), celiac disease, and gut permeability (leaky gut) can damage intestinal cells that produce DAO enzymes, leading to excess histamine. Certain drugs including some antibiotics, anti-depressants, and pain relievers can block DAO activity or release histamine from cells. Consuming excessive amounts of histamine-rich foods can overwhelm even normal DAO levels, temporarily creating intolerance symptoms.