DAO Enzyme Supplements: Research Studies and Genetic Connections
Diamine oxidase, or DAO, is an enzyme produced primarily in the gut to break down histamine from food or the gut microbiome. The small amounts of histamine obtained from foods or from the gut microbiome are usually broken down in the intestines by diamine oxidase (DAO). However, when there is damage in the intestines or a genetic impairment of DAO, the histamine from foods can be enough to trigger systemic reactions.
Foods that are particularly high in histamine include
- red wine
- aged cheeses
- chocolate
- sauerkraut, fermented foods
- processed meats, aged meats (sausage, pepperoni, jerky)
Histamine can also be synthesized by the gut microbiome. A recent study showed that patients with histamine intolerance had altered microbial composition compared to a healthy control group. The histamine intolerance patients had a higher abundance of bacteria that produced histamine.[ref]
One study showed that people with histamine intolerance “had a significantly higher abundance of histamine-secreting bacteria, including the genera Staphylococcus and Proteus, several unidentified genera belonging to the family Enterobacteriaceae and the species Clostridium perfringens and Enterococcus faecalis.” [ref]
Another study showed that people with histamine intolerance have lower levels of Bifidobacteria.[ref] While I can’t find a specific study showing that bifidobacteria probiotics help with histamine intolerance, anecdotal evidence suggests that they may help.
------------------------
This is just a short excerpt from my in-depth article on DAO. Click here to read my full article
With a Genetic Lifehacks membership, you can use your genetic raw data (from 23andMe, AncestryDNA, etc) to see your genotypes in over 400 articles, including my article on DAO. You will see research-backed solutions in the lifehacks section to help determine what pathway to target -- all based on your genetic variants. Personalize your health!
Posted Dec 6, 2025, 4:59 PM UTC