Histamine & Irritable bowel syndrome (IBS)
Histamine intolerance (HIT) and irritable bowel syndrome (IBS) have similar symptoms and can therefore be easily confused. In addition, it has been shown that histamine can affect IBS. This topic is still a growing area of research, but in this post we will focus on what is currently known about the connection between histamine and IBS.
This is part 3 of the series on Histamine. Also read part 1: Histamine Intolerance and part 2: The Connection Between Histamine Intolerance and the Gut Microbiome , to gain a greater understanding of histamine and histamine intolerance.
What is IBS?
Irritable bowel syndrome (IBS) is a common gastrointestinal disorder, with typical symptoms such as abdominal pain, changes in bowel habits, and bloating .
Knowledge about the specific symptoms is lacking and the symptoms vary between patients, so it is very difficult to diagnose IBS. For example, diarrhea and constipation are two opposites, but both are symptoms of IBS. There is also a subtype of IBS, IBS-M, which has both. However, what is common to the majority of IBS patients is that foods, including histamine-rich foods, trigger their symptoms .
The connection between histamine and IBS
Histamine has been shown to affect IBS. 42-58% of IBS patients experience symptoms from histamine-rich foods or foods that release histamine (e.g. wine, beer, cheese, milk). In addition, dysbiosis, an imbalance between beneficial and non-beneficial bacteria in the gut, is associated with the development of IBS and aggravation of the condition .
IBS also causes inflammation in the intestinal wall, which damages the DAO-producing cells in the lining. DAO is the enzyme that breaks down histamine and ensures healthy histamine levels in the body. Reduced levels of DAO will therefore result in inadequate breakdown of histamine and worsening of IBS symptoms.
In addition to this, IBS patients have a higher number of mast cells , which are also more active than normal. The challenge is that the inflammatory state of IBS patients activates the mast cells, which thereby release histamine at a higher level than normal.
The higher levels of histamine caused by IBS are associated with more pain and symptoms. However, there is an overlapping relationship between IBS and histamine intolerance (HIT) and the exact differences are currently unclear.
How to treat IBS?
The primary treatment for IBS patients is a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) for 4-6 weeks, followed by the reintroduction of FODMAPs one at a time. FODMAPs are foods such as garlic and onions, wheat, dairy products, fruits, legumes, sugar and alcohol. FODMAPs act as prebiotics for some bacteria, but they have poor absorption and draw water into the digestive tract , which causes bloating and other IBS symptoms.
A low-FODMAP diet can reduce histamine levels in IBS patients , both by reducing histamine-containing foods from the diet as well as by reducing inflammation, which has positive effects on mast cells and DAO.
Additionally, this diet is expected to alter the microbiome of IBS patients , as reflected in higher numbers and better distribution of bacteria in the gut. This includes increased levels of SCFA-producing bacteria: Clostridiales , Bacteroides , Prevotella , and Bifidobacteria , which are considered important for gut health.
Key messages
- IBS is a bowel disorder that is difficult to diagnose due to its varying symptoms and because there is overlap with both HIT and other bowel disorders.
- Damaged DAO-producing cells and more activated mast cells lead to increased amounts of histamine in the body, and may play an important role in IBS patients.
- Through a low-FODMAP diet, histamine levels can be reduced in patients with IBS, which can relieve symptoms and at the same time positively affect the composition of the microbiome.
Author: Ingeborg Amble Holtmann
