Im looking at a balance here or maybe a shifted balance (dysregulation)
Maybe how bacteria might affect this balance, or the microbiome.
So not just looking at these human genes, bacteria and fungi can produce histamine. Certain bacteria can also degrade histamine, such as Bifido longum and infantis.
Genes of the Histamine Pathway and Common Diseases
For more than a hundred years since the discovery
of histamine, a large body of data has been accumulated on the importance of this amine for normal body
functioning, as well as for the development of pathologies of various organ systems.
Both temporal and chronic imbalances between the synthesis/intake of histamine and its degradation/metabolism in the human body (including those caused by specific genetic features) mediate the development of inflammatory manifestations with disturbance of the homeostasis of various organ systems (nervous, immune, endocrine, cardiovascular, etc.). Immunopathologic reactions mediated by histamine accompany the development of antigen-specific and nonspecific immediate and delayed-type hypersensitivity reactions of inflammation, effector immunocomplex reactions, autoimmune disorders, and cancer and, ultimately, can determine the comorbidity of common diseases. The review also provides information on the associations of the genes of the histamine pathway with common diseases (according to the studies using the candidate-gene approach and genome-wide association studies).