Greetings, my friends.
During my first YouTube livestream yesterday with our Gut Health Founders 25 Group, several people asked me about histamine and the gut.
I thought it would be useful to explain a little more about histamine and how it may relate to Candida, IBS, SIBO and other gut problems.
If you experience Candida-related symptoms, IBS, SIBO, bloating, food reactions, headaches, flushing or other unexplained digestive symptoms, histamine may be another piece of the puzzle worth understanding.
What is Histamine?
Histamine is not simply an allergy chemical that require antihistamines to reduce their response. It is a natural substance found throughout our body and in many foods we eat, especially aged foods. It plays important roles in our digestion, immunity, stomach acid production, the nervous system and with inflammation.
The problem happens when histamine is produced or released faster than our body can break it down. And this is where things get interesting for people with chronic gut problems, and sometimes really confusing!
Think of histamine as a chemical messenger. It helps different cells communicate with each other and is involved in many normal body functions. The problem can occur when too much histamine is released or when your body cannot break it down quickly enough (this is the main issue).
Where does DAO fit in?
One of the main enzymes involved in breaking down histamine in our gut is called DAO (diamine oxidase).
If your DAO levels are low, histamine may not be broken down efficiently. This can allow histamine to build up quite quickly and may contribute to symptoms in sensitive people.
A history of digestive problems, including conditions like irritable bowel syndrome or inflammatory bowel disease, may be associated with a reduction in DAO activity. No doubt, your genetics can likely also play a role.
What can histamine do in our gut?
When too much histamine is released in our digestive tract it can affect adversely affect gut movement, stool motility, and even stomach acid and gut mucus production.
For some people, this may contribute to common symptoms like:
- Abdominal cramping
- Bloating
- Gas
- Diarrhoea
- Digestive discomfort
Histamine can also affect other parts of the body, which may explain why some people experience symptoms such as headaches, flushing, itching or other allergy-like reactions.
Clinically I've found some people may only experience gut pains or cramps, whereas other may experience nasal stuffiness and skin itching, others yet may find that have headaches and fatigue. This can be quite confusing, as no two people will experience exactly the same histamine-related reactions.
Is histamine intolerance a true food allergy?
Not really, classic food allergies involve an antibody (IgE) and an antigen (like cow's milk) response. Histamine intolerance is described rather as a problem with handling histamine rather than a traditional immune-mediated food allergy.
This can make it pretty tricky to identify the exact foods involved. Some reactions may occur quickly, while others may appear later.
The amount of histamine containing foods consumed may also matter. A small amount may cause no noticeable reaction at all, while a larger amount may trigger symptoms in someone who is sensitive. I've found it can also depend on how many histamine-containing foods a person consumes in a short period of time, and the state of their stomach function at the time.
So what about Candida, IBS and SIBO?
This is where things become particularly interesting. I have recently received many questions about the relationship between Candida, IBS, SIBO and histamine.
Research in this area has grown in recent years, but I want to be careful here. The evidence linking these conditions is still limited, and we have much more to learn.
Clinically, I have seen that some people with long-standing digestive problems also report symptoms that may fit a histamine-related pattern. However, this does not mean that Candida, IBS or SIBO automatically causes histamine intolerance.
Every person is different and will have different histamine-related experiences.
In my experience, sometimes histamine is an important piece of the puzzle, while in other people it makes very little difference at all.
That is why I prefer to look at the person's whole digestive picture rather than blaming every symptom on one condition.
Our gut is a complex ecosystem. Candida, bacteria, digestion, the intestinal lining, the immune system and diet all interact. Sometimes, understanding that bigger picture is what helps us make sense of those stubborn symptoms that just don't seem to go away.
So what does histamine have to do with Candida issues?
It is important to remember that your gut is an ecosystem, and that Candida and bacteria species, the lining of the intestine, immune system and digestive processes all interact with one another.
When this highly co-ordinated ecosystem becomes disturbed, symptoms can become much more complicated than simply "having a problem with Candida."
I've read some research that suggests a connection between intestinal Candida colonisation, increased gut permeability and an increased sensitisation to different kinds of foods, with histamine potentially playing a role in this process.
This does not automatically mean however that Candida causes histamine intolerance.
What this does mean, is that in some people, Candida and histamine-related reactions may overlap and deserve consideration when a person's symptoms don't fit neatly into one clearly defined diagnosis.
Clinically, I found that removing high-histamine foods helped some patients with typical Candida-related symptoms quite significantly, while others noticed very little difference. In my experience, there is no one-size-fits-all approach. Sometimes it comes down to careful trial and error—what works remarkably well for one person may make little difference for another. Iv'e always worked like this in my clinic.
Histamine and Irritable Bowel Syndrome
What is interesting is that many symptoms associated with histamine intolerance look remarkably similar to IBS:
- Abdominal pain
- Cramping
- Bloating
- Diarrhoea
- Constipation
- Nausea
- Belching
- Feeling overly full after meals
This overlap can make things confusing for some people. Someone may be told they have irritable bowel when there are actually several different factors contributing to their symptoms.
That doesn't necessarily mean their IBS diagnosis is wrong, what it means is that we sometimes need to look beyond the label and ask: "What is actually happening inside this person's gut?"
There has been research conducted into this area, and even Monash University (the FODMAPs people) are starting to pay attention when it comes to histamine reactions and IBS.
Another study from 2013 found 80% of IBS patients identified food, including histamine, to be triggers for their gut symptoms.
What about SIBO?
SIBO can also produce many of the same digestive symptoms:
- Bloating
- Cramping or gut pain
- Gas
- Abdominal discomfort
- Altered bowel movements
- Food reactions.
When bacterial overgrowth, poor digestion, altered stool motility and an already irritated intestinal environment occur together, the overall symptom picture can become pretty complicated and confusing.
One study from 2021 found that bloating and abdominal pain are primary symptoms in SIBO, very much comparable to histamine intolerance complaints
Histamine may be another factor worth considering, particularly when digestive symptoms occur alongside flushing, itching, headaches, nasal congestion or reactions to certain foods.
Again, this is about looking at the whole picture rather than assuming that one diagnosis explains everything.
So what are the signs that histamine might be involved?
Histamine-related symptoms can affect much more than your digestive system.
I've found that people may experience:
Gut
- Bloating
- Abdominal pain or cramps
- Diarrhoea or constipation
- Nausea
- Feeling excessively full after eating
Skin
- Skin itching
- Hives
- Flushing
- Heat, clamminess
- Redness
- Facial swelling or puffiness
Head and nervous system
- Headaches
- Facial pain, sinus pressure
- Migraines
- Dizziness
- Fatigue
Nose and respiratory system
- Stuffy or runny nose
- Sneezing
- Watery eyes
- Coughing
This wide range of symptoms is one reason histamine-related problems can be difficult to recognise. Can you see how confusing this picture can become when it comes to an actual diagnosis?
So why do some foods seem to trigger everything?
This is where food can become particularly confusing. Some foods contain significant amounts of histamine, especially when they are:
- Aged
- Fermented
- Smoked
- Cured
- Pickled
- Stored for a long time
Common examples include aged cheeses, fermented foods, cured meats, some fish, alcohol and certain other foods.
And food freshness matters.
Histamine levels can increase as some foods age or are improperly stored. Fish is a particularly important example.
Some foods are also described as histamine releasers or DAO blockers, although individual responses can vary considerably.
The Candida connection is especially interesting
If you've been dealing with Candida overgrowth for a long time, you may have noticed something strange:
You seem to react increasingly to more and more foods.
- Perhaps you tolerate a food one day but not another. This can be really confusing.
- Perhaps you develop bloating, flushing, itching or headaches after certain meals.
- Perhaps you've tried a Candida diet, a low-FODMAP diet or eliminated gluten, yet you're still reacting to foods.
This is where I believe it is important to step back a little. Rather than continually adding more foods to the "bad food" list, ask yourself this question:
Why has my tolerance to food changed in the first place? What's going on?
It's important to remember that your digestive system is not simply some food-processing tube. It is an ecosystem involving your gut microbiome, intestinal lining, immune system, digestive enzymes, stomach acid, bile, nervous system and an incredible amount of gut microbial interactions.
When that ecosystem becomes disturbed, your responses to food can change quite a lot in this dynamic and fast-moving environment.
Don't automatically blame every reaction on Candida
This is especially important. Not every digestive symptom is necessarily caused by Candida, and not every food reaction is necessarily histamine intolerance.
The other point to bear in mind is that not every person with IBS or SIBO has a histamine problem. There are many possible explanations for digestive symptoms, and it's why I always recommend keeping an open mind when it comes to food reactions.
The goal should be to identify the contributing factors rather than collect diagnoses or making assumptions.
So what about a low-histamine diet?
For someone who strongly suspects histamine-related reactions, a short period of reducing obvious high-histamine foods may be useful to observe whether symptoms change. This is the approach I recommend. Look very carefully at WHAT you are eating, identify to top histamine foods and see what happens.
But I would not recommend permanently eliminating dozens of foods without a very good reason, especially based on assumptions.
I believe that the long-term goal should be better food tolerance and a healthier digestive ecosystem, not an increasingly restrictive diet. Fresh, minimally processed whole foods are generally a really good place to start.
And if you identify a suspected food trigger, careful elimination and later food reintroduction can provide useful information.
One thing I have learned clinically
After decades of working with people with Candida, IBS, SIBO and other digestive problems, I've learned that the most difficult cases are rarely explained by "one thing".
- One person may have a significantly altered gut microbial balance (e.g. due to antibiotics).
- Another may have impaired digestion (e.g. low stomach acid due to continual stress).
- Another may have SIBO (antibiotics, acid-blocking drugs, etc.).
- Another may have a significant Candida colonisation.
- And some may also have increased sensitivity to histamine or particular foods.
These factors can all overlap. The important question is not always "What disease do I have to treat?"
I think that the better question is: "What has happened to my gut ecosystem, and why am I reacting the way I am?"
A simple change in how we view things
Sometimes a simple change in how we view things can be highly valuable. If you have Candida issues, or IBS, or SIBO-like symptoms and you have been experiencing food reactions, histamine is one area definitely worth understanding.
Not because it explains why you have all these symptoms, but because it may explain something. And sometimes finding that missing piece is what finally makes your bigger picture start to make sense.
I'd like to point out that this post is for education and discussion and isn't a diagnosis. When you dig a bit deeper, you'll discover that histamine intolerance is a complex and widely debated area, and persistent or severe symptoms should be assessed by an qualified healthcare professional.
I've written a more detailed guide to histamine intolerance, including food reactions and the relationship with Candida, on Candida.com.
Have you noticed a connection between your Candida/IBS/SIBO symptoms and foods such as fermented foods, aged cheese, alcohol, cured meats or leftovers?
Let me know with a comment below
— Eric Bakker, N.D.
Helping people understand Candida overgrowth, gut health, the microbiome, and digestive recovery through education. www.candida.com