Histamine Intolerance - State of Knowledge and Enzymatic Intervention Points [24.10.22]

So far, histamine intolerance cannot be treated with a specific medication. People who are affected can only prevent or reduce the symptoms occurring, sticking to a low-histamine diet (Reese et al. 2021). Diamine oxidase is expressed especially in the intestine, kidney and placenta and stored in vesicular structures for secretion (Schwelberger et al. 1998; McGrath et al. 2009). The underlying cause of histmain intolerance is an inefficient human diamine oxidase (DAO) activity in the gastrointestinal tract, which leads to incomplete degradation of food-related histamine, which in turn surpasses into the bloodstream causing histamine-related symptoms. DAO insufficiency might be due to either a genetic predisposition or be an acquired condition (Ayuso et al. 2007). This review from Lutz Fischer's group deals with the advances and challenges of DAOs and other histamine-oxidizing enzymes for their potential application as processing aids for the production of histamine-reduced foods or as orally administered adjuvants to humans who have been eating food fraught with histamine.

Histamin Molecule (Source Wikipedia)

Original Article

Kettner, L., Seitl, I. & Fischer, L. (2022) Recent advances in the application of microbial diamine oxidases and other histamine-oxidizing enzymes World J Microbiol Biotechnol 38, 232. doi.org/10.1007/s11274-022-03421-2

Abstract

The consumption of foods fraught with histamine can lead to various allergy-like symptoms if the histamine is not sufficiently degraded in the human body. The degradation occurs primarily in the small intestine, naturally catalyzed by the human diamine oxidase (DAO). An inherent or acquired deficiency in human DAO function causes the accumulation of histamine and subsequent intrusion of histamine into the bloodstream. The histamine exerts its effects acting on different histamine receptors all over the body but also directly in the intestinal lumen. The inability to degrade sufficient amounts of dietary histamine is known as the ‘histamine intolerance’. It would be preferable to solve this problem initially by the production of histamine-free or -reduced foods and by the oral supplementation of exogenous DAO supporting the human DAO in the small intestine. For the latter, DAOs from mammalian, herbal and microbial sources may be applicable. Microbial DAOs seem to be the most promising choice due to their possibility of an efficient biotechnological production in suitable microbial hosts. However, their biochemical properties, such as activity and stability under process conditions and substrate selectivity, play important roles for their successful application. This review deals with the advances and challenges of DAOs and other histamine-oxidizing enzymes for their potential application as processing aids for the production of histamine-reduced foods or as orally administered adjuvants to humans who have been eating food fraught with histamine. © 2022, The Author(s).