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One Major Effect Fermented Foods Have on Your Health, Says New Study

These are the anti-inflammatory foods you're not eating enough of.
Examples of fermented foods kimchi beets apple cider vinegar yogurt pickles sauerkraut

If not addressed early, chronic inflammation can cause a host of long-term health issues, including cancer, heart disease, type 2 diabetes, and non-alcoholic fatty liver disease. Healthy choices like dark leafy green vegetables (think kale and spinach), fatty fish (salmon and mackerel), and olive oil are some of the foods that help combat inflammation.

Now, research suggests there's another type of food that may even have a greater impact on staving off chronic inflammation. A new study published in the journal Cell finds that a diet rich in fermented foods (think miso and sauerkraut) enhances the diversity of gut microbes and thus decreases molecular signs of inflammation.

The study involved a clinical trial consisting of 36 healthy adults who were randomly assigned to a 10-week diet that either included foods that were fermented or high in fiber. The researchers found that the two diets had different effects on the gut microbiome and the immune system.

RELATED: The Worst Foods for Gut Health

"Previous work in the field has reported the effects of diet on the microbiome in humans and some have reported measures of host health," lead study author Hannah Wastyk, a PhD student in bioengineering at Stanford University, tells Eat This, Not That!. "However, our study is the first, to our knowledge, to report extensive immune profiling across time to deeply investigate the axis of the diet-microbiome-immune system."

As Wastyk notes, these two specific diets were chosen for the study because they have both been shown to have a positive impact on the gut microbiome. However, the findings from this study reveal that when we eat fermented foods, they introduce their own microbial community to our gut microbiome. This, in part, increases the diversity of the healthy bacteria in the gut that our body requires to ward off the chronic inflammation that can make us more susceptible to infection and chronic disease.

fermented foods in glass jars
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However, that's not to say that those who ate a high-fiber diet didn't experience any gut-related health benefits.

"While we didn't see an increase in diversity as expected, we did see an increase in microbial capacity to metabolize plants. The more fiber people ate, the better able their microbiome got at digesting it," Wastyk says. "These results were promising and suggest that if the study was extended for a longer period of time, we might have seen a more substantial microbial and immune response in the high-fiber diet group."

The subjects that came into the study with a more diverse gut microbiome and consumed a high-fiber diet had improved immune status by the end of the 10-week period. 

"Because the high-fermented food diet had such a striking response to reproducibly increase microbiome diversity, one can imagine that a hybrid diet, high in [both] fermented foods and high in fiber, might synergize the effects seen here for an even larger impact on improving immune status," Wastyk says.

As Vincent M. Pedre, MD, medical director of Pedre Integrative Health and author of "Happy Gut" points out, many people in the U.S. (and other western societies) have low gut microbiome diversity as a result of dietary choices, lifestyle habits, and even medication.

"Usually, gut microbiome diversity is low as a consequence of exposure to antibiotics, the standard American diet, alcohol, and even stress," he says.

The findings of this study provide hope, as they suggest that upping your intake of fermented foods may help to reduce inflammation brought on by all of these factors. Pedre offers a few examples of fermented foods that you can start adding to your diet today. They include:

  • Greek yogurt
  • Kefir
  • Fermented cottage cheese
  • Sauerkraut
  • Sauerkraut juice
  • Kimchi
  • Pickles
  • Fermented vegetables
  • Kombucha
Bowl of greek yogurt
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Pedre also notes a few limitations of the study. A) It was a small, randomized prospective study that only included 18 people in each group, and B) the groups mainly comprised of white women.

"Due to the homogeneity of the participants, it would be great to repeat this study with a more diverse study population to see if these effects can be extrapolated to both men and women, as well as different ethnicities," he says.

For more, be sure to check out The Secret to Avoiding Obesity May Lie in Your Gut, Says New Study.

Cheyenne Buckingham
Cheyenne Buckingham is the news editor of <Eat This, Not That!, specializing in food and drink coverage, and breaking down the science behind the latest health studies and information. Read more