Dysbiosis — vasoactive amines produced include

• A. Histamine and tyramine
• B. Serotonin and dopamine
• C. GABA and glutamate
• D. Acetylcholine and norepinephrine

Answer: (A)

In dysbiosis, certain gut bacteria gain the ability to produce biogenic amines that affect vascular tone. The classic vasoactive amines produced by decarboxylation of amino acids are histamine and tyramine. Histamine comes from histidine via histidine decarboxylase and can cause vasodilation and increased vascular permeability, contributing to inflammatory-type responses. Tyramine comes from tyrosine via tyrosine decarboxylase and can trigger release of norepinephrine, leading to vasoconstriction and potential rises in blood pressure, especially in sensitive individuals or when MAO inhibitors are involved.

The other pairs involve neurotransmitters like serotonin, dopamine, GABA, glutamate, acetylcholine, and norepinephrine, which are not the primary biogenic amines typically highlighted in dysbiosis as vasoactive agents.