Fermented Cabbage Helps Heal Gut Damage from Unhealthy Diets
A new study on nutrition and supplement science shows that fermented cabbage can protect the gut from inflammation caused by poor dietary choices. Experts now recommend eating fermented foods daily, and suggest one food in particular as especially beneficial.
In Germany, it’s called sauerkraut. France’s Alsace region, it’s known as choucroute. In Korea, the spicy version is called kimchi. In the U.S., it’s often just a topping for hot dogs. But fermented cabbage may offer much more than flavour.
Researchers have long known that eating fermented foods is good for your health. Now, new research from the U.S. adds a significant finding: Fermented foods may help prevent leaky gut, a condition linked to the development of autoimmune and inflammatory diseases affecting millions.
This is according to Professor Oluf Borbye Pedersen, a leading expert in human metabolism and the gut microbiome at the University of Copenhagen and Gentofte Hospital. Although not involved in the study, he supports its findings.
Just a Small Bite Makes a Big Difference
A study, co-authored by Maria Marco, professor of food science at the University of California, found that even a small portion of sauerkraut can make a measurable difference.
“We should include fermented foods in our regular diet—not just as a topping on hot dogs,” says Marco.
It Must Be Fermented to Work
Researchers analysed over 100 compounds in fermented cabbage extract and found substances known to support gut barrier function. They compared three forms of cabbage: raw, fermented, and the leftover fermentation brine. Only the fermented cabbage showed protective effects against inflammation in intestinal cells. Still, Pedersen stresses that raw cabbage is also healthy due to its other beneficial compounds and shouldn’t be avoided.
Homemade or Store-Bought? What Does Nutrition & Supplement Science Say
The team tested lab-made fermented cabbage against store-bought versions and found no difference in effectiveness—both support gut health.
Study source: The fermented cabbage metabolome and its protection against cytokine-induced intestinal barrier disruption of Caco-2 monolayers (Published in Applied and Environmental Microbiology)
How the Study Worked: Simulating a Leaky Gut
To simulate a leaky gut, scientists from the nutrition and supplement science used an artificial intestinal wall and exposed it to cytokines—proteins that trigger inflammation. These are activated in the body by diets high in ultra-processed foods, sugar, animal fat, or salt.
“A leaky gut allows unwanted substances to pass into the bloodstream, triggering inflammation,” says Pedersen. “It’s a growing health issue linked to chronic unhealthy diets.”
Chronic inflammation has been connected to conditions such as heart disease and depression.
It’s Not Just Cabbage: Cheese, Tea, and More
Pedersen highlights that other fermented foods also support gut health:
- Kombucha (fermented tea)
- Kefir (fermented milk or water)
- Aged cheeses
- Air-dried (fermented) ham
Kefir: The “Outstanding” Option
Among these, Pedersen singles out kefir as especially powerful.
“Kefir is likely the easiest and most effective option for many people,” he says. Unlike yoghurt or skyr, which contain only a few bacterial strains, kefir contains more than ten health-promoting bacteria and yeasts.
He adds: “Kefir helps stabilise the complex ecosystem of gut microbes and plays a key role in preventing leaky gut.”
Correction (May 5, 2025):
An earlier version of this article incorrectly stated that Norwegian sauerkraut is fermented. It is not—its sour flavour comes from vinegar (acetic acid), according to the Store norske leksikon (Great Norwegian Encyclopedia).
Key Takeaways
Fermented Cabbage Supports Gut Health: A new study shows fermented cabbage helps protect the gut from inflammation caused by unhealthy diets. It may also prevent “leaky gut,” a condition linked to autoimmune and inflammatory diseases.
Scientific Study Highlights: Researchers used artificial intestinal walls and induced inflammation using cytokines (proteins activated by poor diets). Only fermented cabbage, not raw cabbage or brine, protected gut cells from inflammation.
Homemade vs. Store-Bought: No difference in health benefits between lab-made and store-bought fermented cabbage—both are effective.
More Than Just Cabbage: Other fermented foods also promote gut and overall health, including –
- Kombucha (fermented tea)
- Kefir (fermented milk or water)
- Aged cheeses
- Air-dried fermented ham
Kefir: Highly Recommended: Professor Oluf Borbye Pedersen calls kefir the “most effective” fermented food. It contains 10+ strains of beneficial bacteria and yeasts, far more than yoghurt or skyr. It stabilises the gut microbiome and prevents leaky gut.
Important Correction: Norwegian “sauerkraut” is not fermented; its sour taste comes from vinegar.
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