Histamine Intolerance: Mechanisms, Dietary Approaches, Microbiota Modulation, and Supplementation Strategies

Introduction: It is estimated that about 20–35% of the Western population reports symptoms of food intolerances, which is a growing trend. Intolerance to histamine, a dose-dependent, non-allergic food hypersensitivity reaction, despite similar clinical manifestations, has mechanisms distinct from food allergies. Objectives: This narrative review aims to ascertain and synthesize the evidence on the role of nutrition, microbiota modulation, and food supplementation in histamine intolerance. Methods: The search was conducted between September and October 2025 in the PubMed and ScienceDirect databases, using terms related to “histamine intolerance” and considering the last 10 years. 43 scientific articles and 5 additional regulatory and guidance documents were included. Results: The clinical manifestations of histamine intolerance are heterogeneous and complex, and different responses may occur in the same individual with equal doses of histamine. In the literature, intestinal dysbiosis promotes a local and systemic increase in histamine, triggering symptoms in predisposed individuals. The low-histamine diet induced a significant reduction in cutaneous and gastrointestinal symptoms. The literature also shows that diamine oxidase enzyme supplementation is promising in the treatment of migraines and chronic urticaria, contributing to a reduction in the dose and frequency of drugs. In addition, vitamins C and B6, S-adenosylmethionine, and magnesium have been studied in therapy. Conclusions: Histamine intolerance represents a challenge in clinical practice due to its complexity, symptomatologic diversity, and the lack of consensus regarding diagnosis and treatment.