Urinary Histidine Excretion in Patients with Classical Allergy (Type A Allergy), Food Intolerance (Type B Allergy), and Fungal‐type Dysbiosis

Changes in histidine excretion reflect histidine conservation and thus the level of histamine secretion. Low levels were found in untreated patients with atopic (type A) allergy. However, levels in food intolerance (type B allergy) and fungal‐type dysbiosis were also low (p<0.001 for each group compared with nonallergic controls). There were no differences between the three groups. The biochemical and clinical significance of these findings is discussed.