An amino acid test I had showed histidine somewhat low. And then I thought about metabolic alkalosis and what the lungs do to decrease PH...they hold on to C02. Everyone here I have talked to seems to have breathing issues...infrequent and shallow breathing. Signs of metabolic alkalosis possibly. And they have gut problems. Signs of malabsorption...low HCL. Allergies and whatnot...creating more histamine depletion by the gut irritants of undigested food. The low histidine initially causes low stomach acid. Then the undigested food causes allergies depleting histidine/histmine further. Histidine should in theory increase the stomach acid and help the problem. Will let you guys know. Rich feel free to comment. I feel best on digestive enzymes. Histamine acts as a neurotransmitter and wakes us up. I could see how this could be a vicious cycle.