HSA | FSA CARDS ARE NOW ACCEPTED

MAOB and Histamine: What Your Genes Mean for Histamine Balance

Histamine helps the body respond to allergens, regulate stomach acid, and support brain function and sleep. When histamine is balanced, these systems work smoothly. When histamine builds up, people may experience headaches, digestive upset, skin reactions, nasal congestion, or other symptoms often described as histamine intolerance.

The MAOB gene codes for the enzyme monoamine oxidase B, or MAO-B. One of MAO-B's jobs is to break down histamine. Variations in the MAOB gene can change how well MAO-B works. That affects how efficiently histamine is cleared from the body and how likely histamine is to accumulate after eating certain foods or in response to environmental triggers.

This article explains common MAOB genotypes for the rs2283729 variant and what they tend to mean for histamine metabolism. It also offers practical, evidence-informed strategies for diet, supplements, lifestyle, and testing that may help manage histamine-related symptoms. PlexusDx does not provide medical advice. Always consult your healthcare provider before making changes to your diet, supplement routine, or medical care.

How to read this result

  • Two effect alleles (AA): associated with reduced MAO-B activity and higher histamine buildup risk.
  • One effect allele (AG): associated with moderately reduced MAO-B activity and intermediate histamine risk.
  • No effect alleles (GG): associated with more efficient MAO-B activity and lower histamine buildup risk.

Practical goals if you are concerned about histamine

  • Reduce exposure to high-histamine foods and beverages.
  • Support MAO-B activity with targeted nutrients where appropriate.
  • Keep gut microbiome and digestive function healthy to limit histamine production.
  • Manage lifestyle factors that influence histamine release and breakdown.
  • Work with your healthcare provider to test and monitor symptoms and relevant labs.

Genetic Interpretations

Two effect alleles (AA) — Reduced MAO-B activity

If your genotype is AA at rs2283729, you carry two copies of the effect allele. This is associated with reduced MAOB activity. Your MAO-B enzyme may not break down histamine as efficiently, increasing the likelihood that histamine will linger in the body. This can raise sensitivity to histamine-rich foods and to some environmental triggers.

Common symptoms linked to higher histamine include headaches or migraines, bloating or diarrhea, flushing or itching, nasal congestion, and sleep disruption. Symptoms may be triggered by aged cheeses, fermented foods, cured meats, shellfish, certain fish, some types of wine and beer, and leftovers that have been stored for a long time.

Consider these strategies:

  • Diet: Start with a short elimination of high-histamine foods while monitoring symptoms. Focus on fresh, minimally processed foods and rotate proteins. Avoid aged cheeses, fermented products, cured meats, smoked fish, kombucha, and tap and fermented beverages.
  • Supplements: Discuss riboflavin (vitamin B2) and flavonoid-containing supplements with your clinician. Some nutrients may help support MAO enzyme function. Support overall methylation and B vitamin status with a multivitamin if indicated.
  • Gut health: Use probiotics selectively. Choose strains less likely to produce histamine and prioritize prebiotic fiber to support beneficial gut bacteria. Treat small intestinal bacterial overgrowth if suspected under medical supervision.
  • Lifestyle: Prioritize sleep, hydration, and stress reduction. Engage in regular moderate exercise. Reduce alcohol and limit excessive caffeine.
  • Testing: Work with your provider to rule out other causes of symptoms. Consider food symptom tracking, elimination diet guidance, and tests for gut health, nutrient deficiencies, or mast cell activation if clinically indicated.
One effect allele (AG) — Moderately reduced MAO-B activity

If your genotype is AG at rs2283729, you carry one copy of the effect allele and one copy of the non-effect allele. This pattern is associated with slightly reduced MAOB activity. You may have a moderate tendency toward histamine buildup compared with people who carry two non-effect alleles.

Symptoms can be similar to those listed above but may be milder or occur only during periods of high histamine exposure, illness, gut imbalance, or stress.

Consider these strategies:

  • Diet: Keep a food diary and limit known high-histamine foods if you notice symptoms. Emphasize fresh fruits and vegetables, fresh meats, and home-cooked meals. Avoid leftovers that have been stored for long periods.
  • Supplements: Talk with your clinician about trying riboflavin, quercetin, or other flavonoids which may support histamine metabolism and stabilize mast cells. Check B12 and folate status as part of overall support.
  • Gut health: Manage dysbiosis and constipation. Consider a probiotic trial with strains shown to be neutral or beneficial for histamine balance, and increase soluble fiber intake to support healthy microbial communities.
  • Lifestyle: Reduce factors that increase histamine release such as poor sleep, chronic stress, and excessive alcohol. Aim for consistent sleep and moderate physical activity.
  • Testing: If symptoms persist, work with a clinician for targeted testing, tailored elimination diets, or referral to a specialist for evaluation.
No effect alleles (GG) — More efficient MAO-B activity

If your genotype is GG at rs2283729, you carry two copies of the non-effect allele. This is associated with more efficient MAOB activity and better histamine breakdown. You are less likely to experience histamine accumulation from typical dietary sources or environmental exposures.

Even with efficient MAO-B, other factors can increase histamine such as gut dysbiosis, medication interactions, or mast cell activation. Follow general healthy habits to maintain balance.

Consider these strategies:

  • Diet: No special restrictions are required based on genotype alone, but pay attention to foods that trigger you personally. Maintain a varied, minimally processed diet.
  • Supplements: Routine supplementation is not typically necessary for histamine control with this genotype. Use supplements based on clinical need rather than genetic risk alone.
  • Gut health: Support microbiome diversity with fiber rich foods and fermented foods if tolerated. Monitor for signs of food sensitivities or GI issues.
  • Lifestyle: Continue healthy sleep, stress management, hydration, and exercise habits to reduce risk of histamine-related symptoms from non-genetic causes.
  • Testing: Seek medical evaluation for persistent symptoms since causes other than MAOB variation may be responsible.

Diet, Supplements, Lifestyle, and Testing — Practical Tips

Diet

  • Limit high-histamine and histamine-releasing foods: aged cheeses, fermented products, cured meats, smoked or pickled fish, kombucha, and certain alcoholic beverages.
  • Prefer fresh, minimally processed foods. Cook and eat proteins soon after purchase rather than store long term.
  • Rotate foods to avoid repeated exposure to the same high-histamine items.
  • Keep a symptom and food diary to identify personal triggers.

Supplements

  • Riboflavin (B2): May support MAO enzyme activity. Discuss dose and need with your provider.
  • Flavonoids such as quercetin: May stabilize mast cells and support histamine balance. Discuss safety and interactions with medications.
  • General B vitamin and nutrient repletion: Correct deficiencies that can affect metabolism and enzymatic function under clinician guidance.

Lifestyle

  • Sleep: Aim for consistent restorative sleep to help metabolic and immune balance.
  • Stress: Use relaxation practices, mindfulness, or therapy to reduce chronic stress that can increase histamine release.
  • Exercise: Regular moderate exercise supports immune and digestive health. Avoid extreme exertion if it worsens symptoms.
  • Hydration: Stay well hydrated to support metabolic clearance.

When to test or seek care

  • Persistent or severe symptoms such as recurrent migraines, significant GI distress, or systemic allergic-type reactions should prompt medical evaluation.
  • Work with your healthcare provider for targeted testing, which may include nutrient levels, gut microbiome evaluation, or referral to allergy or immunology specialists.
  • Do not start or stop prescription medications without discussing with your provider. Some medications interact with MAO enzymes.

PlexusDx provides educational information about genetic predispositions. This content is not medical advice. Always consult your healthcare provider to interpret your genetic results in the context of your medical history and to design a personalized plan for diet, supplements, testing, or treatment.