Untangling gut dysbiosis and histamine intolerance

By Katherine Shagoury

Properly understanding the connection between gut dysbiosis, immune activation, and histamine intolerance can make a difference for treating patients, said Michael Ruscio, DC, owner and clinician at The Ruscio Institute, at the 2019 Integrative Healthcare Symposium in New York City.

Research already shows the connection between gut dysbiosis and the immune system, he said.  

“We know that dysbiosis impact histamine intolerance,” said Ruscio. “The deeper question is how do we unravel this knot?”

The first step, he said, is to understand the symptoms, which include neurological, dermatological, rheumatological, insomnia and fatigue, cardiac, and gastrointestinal manifestations. When it comes to pathophysiology, dysbiosis reduce histamine degradation, and directly and indirectly increases histamine levels.

Dysbiosis may also lead to increased histamine production via increased immune system activation, Ruscio said. Therefore, treating dysbiosis will result in reduced immune activation.

A 2018 study in the Journal of Physiology and Pharmacology concluded, “…the altered occurrence of Proteobacteria and Bifidobacteriaceae, reduced alpha-diversity as well as elevated stool zonulin levels suggest a dysbiosis and intestinal barrier dysfunction in histamine intolerant patients, which in turn may play an important role in driving disease pathogenesis.”

This is good news, Ruscio said, because it is treatable.

One protocol that clinicians can use, he said, is a low Fermentable Oligo-, Di-, Mono-saccharides, and Polyols (FODMAP) diet, which has been shown to reduce irritable bowel syndrome (IBS) symptoms, hydrogen gas levels, and histamine eightfold, according to a 2017 study in the journal Gut.

A low FODMAP diet may reduce immune activation as well, Ruscio said. Dysbiosis directly produces histamine and can also damage intestinal villi that are responsible for production of enzymes that degrade histamine. Diet must be top of mind, he said.

Carbohydrate malabsorption and histamine intolerance may be linked, research says. A low FODMAP diet may heal the gut, specifically by resurrection dwindling serotonin and peptide YY (PYY) cells. Further, a histamine-reduced diet leads to increased serum diamine oxidase (DAO), likely due to gut healing. Histamine intolerance, Ruscio said, is distinguishable from a food allergy, per scientific data.

Optimizing gastrointestinal function is a key pillar in resolving histamine intolerance, Ruscio said. If practitioners solely go after the histamine levels and release, it will likely lead to suboptimal results as it misses the underlying cause, he said.

A significant amount of time is spent on developing guidelines to diagnose histamine intolerance, but Ruscio said he does not find them clinically necessary. By the time a patient is diagnosed, they could be well on their way to fixing the problem.

Definitive testing has not been established, he said, though DAO blood levels less than 10 increases a patient’s risk. However, the lab finding requires a corresponding clinical context of gastrointestinal symptomatology, plus a response to a low histamine diet to be considered diagnostic.

Ruscio offers several dietary strategies for approaching these gut dysbiosis and histamine intolerance cases. The sequence for the protocols, he said, is incredibly important.

“What thwarts people between success and failure clinically is oftentimes not knowing the proper sequence for various treatments,” he said. “If they were done in the correct order, the patients would be much better off.”

Start with a basic elimination Paleo-like diet for three to four weeks, Ruscio said. The idea is to heal the gut and reduce immune activation, which will likely improve dysbiosis.

The next step is to escalate to a low FODMAP diet, which may be done in a Paleo format. A low FODMAP diet will lead to reduce histamine, immune activation, and dysbiosis, he said.

Finally, consider either Paleo, low FODMAP, or Paleo-low FODMAP combined with a low histamine diet. The patient should trial this for one week to determine if it is helpful or not, Ruscio said.

At any point, practitioners should consider intermittent fasting or fasting to reduce gastrointestinal inflammation and antigenic load, Ruscio said, and should work with patients to reintroduce foods after elimination.

Beyond diet, Ruscio says clinicians must incorporate lifestyle and environmental strategies in to their protocols, including exercise, stress management, probiotics and supplementation, and other gut healing strategies.

“If you work through this [treatment hierarchy] methodically, you can get phenomenal results,” said Ruscio. “It’s not very complicated if you have a good model to work through.”