The Connection Between SIBO & Histamine Intolerance

Small intestinal bacterial overgrowth (SIBO) and histamine intolerance are relatively new health diagnoses.

In the past, symptoms for both conditions were lumped with other gastrointestinal (GI) conditions, food allergies, or intolerances.  

Current research indicates SIBO and histamine intolerance are treatable GI conditions.

Proper testing can help you determine the cause of your symptoms and help you on your way to recovery. 

Common symptoms for both SIBO and histamine intolerance include bloating and abdominal pain, skin changes, headaches, and mood changes.

Gut bacteria changes linked with SIBO can predispose or worsen histamine intolerance. 

Both conditions can be treated with dietary changes that significantly improve symptoms.

Learn how a registered dietitian can help you manage these conditions. 

{{splash}}

What is SIBO? 

SIBO occurs when excess bacteria found in the large intestine (colon) is present in the small intestine.

The large intestine should contain bacteria, whereas the small intestine normally maintains low amounts.   

Most research reports that about 2 to 22% of the general population is affected by SIBO.

Usually, stomach acid and the speed at which food and beverages pass through the intestines limit small intestinal bacteria growth.

‍Alterations in gastrointestinal tract anatomy (diverticuli, adhesions, etc.) can also predispose someone to SIBO. 

When these protective measures no longer work, along with other causes, SIBO can occur, causing unpleasant GI side effects, including nutritional deficiencies and intolerances to certain foods. 

What is Histamine Intolerance? 

Histamine intolerance is a condition that affects 3 to 6 % of the population and is often misdiagnosed as a food allergy due to similar symptoms (itching, rash, or diarrhea). 

An intolerance occurs when the body can’t break down histamine well and leads to histamine accumulation, producing skin, blood pressure, or GI side effects. 

Histamine is a compound found in certain foods and beverages, like aged or fermented foods.

Additionally, the body naturally makes histamine in response to allergies or inflammation, which can’t be broken down with histamine intolerance.  

Histamine intolerance is usually caused by genetics, intestinal bacteria changes, food and drugs, or other related diseases (allergies or intestinal and GI disease). 

The Science Behind SIBO and Histamine Intolerance

Research indicates that histamine intolerance is multi-factorial and may be linked to GI bacteria alterations (including SIBO) and a reduced ability to break down histamine and related diseases. 

The body makes an enzyme, diamine oxidase (DAO), that breaks down histamine.

Genetic alterations cause some people to produce less DAO.

Bacteria changes and GI symptoms like bloating and abdominal pain, seen with SIBO, can overlap with histamine intolerance symptoms. 

Additionally, abnormal changes in gut bacteria can lead to increased histamine levels.

‍Certain bacteria (yeasts and molds) can make histamine in the GI tract, increasing some people’s sensitivity to foods and beverages with histamine, leading to worsened symptoms. 

Some people may have both SIBO and histamine intolerance.

Various tests (DAO levels and breath testing) can help determine an effective and tailored treatment plan for both conditions.

Symptoms of SIBO and Histamine Intolerance

Symptoms vary between individuals with SIBO or histamine intolerance. 

Some people produce certain symptoms, but not all, making diagnosis and treatment difficult.

Both conditions are often categorized as food allergies or GI disorders like IBS (irritable bowel syndrome). 

{{splash}}

Digestive Issues 

For both SIBO and histamine intolerance, digestive or GI issues are common. 

With SIBO, two-thirds report bloating, abdominal distension and fullness, gas, abdominal cramps, and diarrhea.

Many people describe chronic fatigue and trouble concentrating. 

In severe cases of SIBO, diarrhea can lead to weight loss, malnutrition, and vitamin deficiencies.

With histamine intolerance, it is important to understand that the GI tract contains most of the histamine receptors, resulting in GI symptoms like stomach ache, bloating, gas, diarrhea, or constipation with accumulations of histamine. 

Skin Problems

Skin problems are commonly associated with GI conditions, including SIBO and histamine intolerance. 

Rosacea is an immune-related skin condition that exhibits facial redness, rashes, visible blood vessels, and irritation to the skin.

‍Research indicates a relationship between rosacea and SIBO. 

SIBO can lead to intestinal cell injury, causing system-wide inflammation, which affects body systems like the skin.

‍Successful antibiotic treatment for SIBO resolved rosacea in almost all patients.

Treating the root cause resolved GI and skin issues.

The skin contains some histamine receptors, which can exhibit alterations due to histamine accumulation.

These uncomfortable symptoms include itchy skin, redness, swelling, and eczema.  

Headaches and Migraines

Headaches and migraines are side effects of histamine intolerance.

Research connecting SIBO to headaches and migraines is limited, although, in theory, GI issues and pain can lead to headaches. 

Migraines were reported in almost 90% of individuals with a DAO deficiency.

The histamine content of foods and beverages like wine triggered migraines and headaches. 

When 100 patients with DAO deficiency were given oral capsules of these lacking enzymes to break down histamine, headache occurrence, duration, and severity were significantly reduced. 

Mood Changes 

Mood changes can be a symptom of SIBO and histamine intolerance, although limited research exists.

For SIBO, small studies have found higher rates of anxiety and stress in people with SIBO compared to those without.

It's thought that altered gut bacteria and unpleasant GI side effects after eating can lead to a depressed mood. 

In individuals with higher levels of histamine (including histamine intolerance), there were higher rates of depression.

Histamine is released in response to the immune system and may play a role in regulating feelings of depression.

Elevated histamine levels are thought to suppress serotonin levels, which can depress mood. 

These non-specific symptoms with a wide range of causes make it difficult to determine the root problem.

Many factors can also cause GI symptoms, skin changes, headaches, and mood changes.

Working with a specialist can help you rule out causes, keep track of symptoms, and see improvement.

Causes of SIBO and Histamine Intolerance 

As mentioned earlier, causes of SIBO can be multifactorial—motility, anatomy changes, immune system, gastric acid levels, and other health conditions predisposing someone to SIBO.

Histamine intolerance is often caused by genetics and intestinal bacteria changes like SIBO, high-histamine foods, certain medications, or other related diseases (allergies or intestinal and GI diseases).  

Some medications reduce DAO levels, allowing for increased accumulation of histamine.

About 20% of people take routine medications that lower DAO levels, including nonsteroidal anti-inflammatory drugs. 

Both conditions can coincide.

Testing can help determine if you have SIBO, histamine intolerance, or other GI conditions.

{{splash}} 

Managing and Overcoming SIBO and Histamine Intolerance 

Working with a knowledgeable healthcare provider can ensure proper testing. 

SIBO is generally diagnosed with a breath test and symptoms.

‍Treatment involves antibiotics to stop the bacteria overgrowth and allow for the repletion of nutrients.

About 45% of people will have recurrent SIBO and require further antibiotic treatment.

Dietary changes can reduce bacteria growth while taking antibiotics.

The low FODMAP diet followed for up to six weeks can help reduce symptoms and growth of bacteria until the antibiotic reduces any overgrowth. 

Histamine intolerance can be diagnosed with testing of DAO levels and discussion of symptoms.

More expensive testing, like intestinal biopsies, can be done to confirm a lack of DAO (the enzyme responsible for breaking down histamine). 

Following a low-histamine diet requires no medications, testing, or supplementation of DAO enzymes.

Consuming low-histamine foods can reduce histamine levels in the body. 

Usually, after four to eight weeks of a low-histamine diet, histamine intolerance symptoms significantly improve and should be considered a simple diagnosis and treatment plan. 

{{local}}

Takeaway

SIBO and histamine intolerance symptoms often overlap and can be confused with other GI, food allergy, or intolerance symptoms.

GI symptoms, skin changes, headaches, and mood changes can be symptoms of both conditions (or other health conditions). 

Seeking professional help and testing can help you determine the cause of your symptoms and help you on your way to recovery. 

Both conditions can be treated with dietary changes that significantly improve symptoms.

Working with a registered dietitian is critical for long-term management. 

How a Dietitian Can Help 

Partner with a knowledgeable, compassionate gut health RDN. 

Registered dietitians can help you develop an eating plan that makes sense and manages your SIBO and histamine intolerance symptoms.

They can help you know what foods to avoid and eat for the best improvement.   

Find a dietitian that accepts insurance through Nourish.