By Dr. Michael Zechmann-KhreisKombucha, kimchi & co. are regarded as real gut boosters – but they can trigger symptoms if you have histamine intolerance, fructose malabsorption or irritable bowel syndrome.
Find out which fermented foods can be problematic, what you should look out for and how you can find out whether they are suitable for you and your food intolerance.
What are fermented foods?
Fermentation is a natural process in which microorganisms, primarily lactic acid bacteria or yeasts, break down sugar. The result: lactic acid, gases, sometimes alcohol – and lots of flavor.
Typical fermented foods:
- Sauerkraut
- Kimchi
- Kombucha
- Kefir
- Yogurt
- Tempeh
- Miso
- Soy sauce
They often contain probiotic bacteria, which are considered beneficial for intestinal health – but unfortunately not for every intestine!
Why fermented foods can be problematic for intolerances
Histamine intolerance
Fermentation significantly increases the histamine or biogenic amine content. These are particularly critical:
- Sauerkraut
- Kombucha
- Miso
- Soy sauce
- Matured cheese
Typical symptoms: Reddening of the skin, headache, nausea, digestive problems.
Tip: If you have a histamine intolerance, avoid as much as possible or test small amounts with a food diary. Yoghurt in particular sometimes works quite well!
Fructose malabsorption
Many fermented products contain fructose-rich vegetables or added sugar (e.g. kombucha) or sugar alcohols.
Consequences can be: Flatulence, abdominal pain, soft stools.
Recommendation: Check the list of ingredients, better make your own, test small quantities.
Lactose intolerance
Dairy products such as yogurt or kefir often contain less lactose and are well tolerated.
Better: Plant-based alternatives such as coconut or soy yogurt, which are also healthier if no sugar or sweeteners are added.
FODMAP sensitivity / irritable bowel syndrome (IBS)
Many ferments are based on FODMAP-rich foods such as cabbage, pulses or wheat.
Tip: Don’t avoid everything across the board – but test individually, possibly under guidance or with a symptom diary.
Who benefits from fermented foods?
People with a stable digestive system, healthy intestinal flora or after taking antibiotics can benefit from fermented products – e.g. to recolonize the intestines with beneficial bacteria. Intolerance patients in particular can benefit greatly from fermented products, subject to the given precautions and individual tolerances.
Ferments & intolerances at a glance:
| Intolerance / sensitivity | Recommendation |
|---|---|
| Histamine intolerance | Avoid or test very carefully |
| Fructose malabsorption | Check ingredients, test small quantities |
| Lactose intolerance | Prefer lactose-free or plant-based ferments |
| Irritable bowel syndrome / FODMAP sensitivity | Test individually in consultation, avoid if necessary |
My personal tip:
Test new fermented foods in small portions and keep a symptom diary – e.g. with our Ask Ingrid app.
This will help you to quickly recognize what is good for you – and what is not.