Low histamine diet and diamino oxidase enzyme supplementation
Symptoms associated with histamine intolerance due to DAO deficiency
Current interventions as of 27/04/2026: A total of 300 patients divided into eight treatment groups (50 individuals per group) will be assigned randomly using a computer-generated random number table: 1. PLACEBO GROUP: 50 participants will receive a gastro-resistant mini tablet (placebo) (three times/day, 20 minutes before each meal) and follow a Mediterranean-style diet. 2. DIET GROUP: 50 participants will receive a gastro-resistant mini tablet (placebo) three times/day (20 min before each meal) and will follow a low histamine diet. 3. PIG DAO SUPPLEMENT + MEDITERRANEAN DIET: 50 participants will receive a gastro-resistant mini tablet with the animal DAO enzyme (4.2 mg) three times/day (20 min before each meal) and will follow a Mediterranean-style diet. 4. PIG DAO SUPPLEMENT + LOW HISTAMINE DIET: 50 participants will receive a gastro-resistant mini tablet with the animal DAO enzyme (4.2 mg) three times/day (20 min before each meal) and will follow a low histamine diet. 5. VEGETABLE DAO SUPPLEMENT + MEDITERRANEAN DIET: 50 participants will receive a gastro-resistant mini tablet with the vegetable DAO enzyme (4.2 mg) three times/day (20 min before each meal) and will follow a Mediterranean-style diet. 6. VEGETABLE DAO SUPPLEMENT + LOW HISTAMINE DIET: 50 participants will receive a gastro-resistant mini tablet with the vegetable DAO enzyme (4.2 mg) three times/day (20 min before each meal) and will follow a low histamine diet. The interventions will last for a period of 3 months, after which they will be re-evaluated by the medical team to assess the degree of effectiveness of the administered intervention. The combination of these groups will allow: 1. The comparison of the PLACEBO and DAO groups will allow the researchers to determine the effect of DAO supplementation on the reduction of symptoms. 2. The comparison of the PLACEBO and DIET groups will allow the researchers to determine the effect of diet on the reduction of symptoms. 3. The comparison of the DAO
1. Adults over 18 years of age 2. Recent history of two or more symptoms associated with histamine intolerance (headache, dermatological, respiratory, and digestive) 3. Present altered plasma DAO enzyme activity and/or have any of the genetic variants of DAO deficiency: 3.1. SNP-type variants associated with reduced levels of DAO activity (oral mucosal smear or blood) 3.2. rs10156191 3.3. rs1049742 3.4. rs1049793 3.5. rs2052129 4. Not having started dietary treatment (low histamine diet/DAO enzyme supplementation) before starting the study
1. Food and/or environmental allergies 2. Have taken pharmacological treatment with antibiotics or probiotic supplements in the last month before the start of the study 3. Being pregnant