Let’s Talk Nutrition with Nico: Gut Health, Histamine and Food Reactions

In the first episode of their new collaborative video series, Let’s Talk Nutrition with Nico, Nico Saraceno, senior editor of Nutritional Outlook, and Lana Pine, senior editor of The Educated Patient, are bringing together patient education and nutrition-focused reporting to help audiences better understand complex health topics.

The debut episode focuses on the emerging science surrounding histamine intolerance, also known as HIT. The discussion explored what researchers currently know — and still do not know — about the condition.

Saraceno explained that histamine is a chemical released by the immune system during allergic reactions and is commonly associated with symptoms such as itching, swelling, hives, congestion and runny nose. However, the review discussed in the episode suggests that histamine intolerance may involve a much broader range of symptoms, including headaches, bloating, fatigue, abdominal pain and inflammation.

Central to the discussion was the role of diamine oxidase (DAO), an enzyme responsible for breaking down histamine in the gut. According to the research, reduced DAO activity may allow histamine to accumulate in the body, potentially contributing to ongoing symptoms in some individuals.

The episode also highlighted the growing interest in the gut microbiome and its possible connection to histamine intolerance. The review suggested that some individuals with HIT may have higher levels of histamine-producing bacteria in the gut, which could make it more difficult for the body to regulate histamine effectively.

At the same time, the conversation emphasized that histamine intolerance remains difficult to diagnose. Saraceno noted that there is currently no universally accepted diagnostic test or biomarker for HIT, including DAO blood testing, which has shown inconsistent reliability in research. Because of this, health care professionals often rely on symptom tracking, elimination diets and food reintroduction strategies to help identify potential triggers.

The episode explores promising — though still preliminary — findings related to DAO supplementation and personalized low-histamine diets. One observational study involving 82 participants found that individuals reported significant symptom improvement after taking DAO supplements before meals for four weeks.

However, both Pine and Saraceno stressed the importance of interpreting the findings carefully. Many of the studies remain early-stage or observational, and histamine intolerance itself continues to be debated in parts of the medical community due to the lack of standardized diagnostic criteria.

Ultimately, the inaugural episode underscores a larger message: nutrition, gut health, genetics and inflammation are deeply interconnected, and understanding those relationships may help patients make more informed health decisions moving forward.