A New Study on Fermented Foods and the Microbiome

Table of Contents
  1. What was tested?
  2. The results
  3. How this study changed my diet

I want to talk about a study that’s really changed how I’m eating, and I think it’s really going to impress you, especially if you’ve been curious about fermented foods, the microbiome, or you’re hearing all this buzz about inflammation and how it relates to your health and mental health. This study helps us know what to do a little bit more.

What was tested?

It’s a great trial that looked at giving individuals more fermented foods. It focused on getting folks to eat more of all those good bugs that I talk about in Eat to Beat Depression and Anxiety. These are things like kombucha, kefir and yogurt. They went from about half a serving a day up to six servings a day. There was another group where they just gave them more plants and more fiber. They looked at a lot of details of what happened in the microbiome, what kind of proteins got produced, whether there was a change in the diversity of the microbiome. They looked at these individuals over 17 weeks and really were careful in modulating their diet.

The results

They found that individuals who ate more fiber or started to add more plants in their diet did not have a change in their immune status, inflammatory markers or microbiome diversity. Eating more plants just gets more bugs but you don’t change those really important factors. When they looked at the effect of the fermented foods, they found changes in many microbiome diversity and immune status so decreases in biomarkers of inflammation like CRP and interleukin 6. These are the molecules in our blood that tell us how active our immune system is. Eating more plants is great for a lot of reasons but it doesn’t really change your microbiome or your immune status in the way that we’re hoping for.

How this study changed my diet

This is a great study that really helps us think about how best to take care of our mental health in terms of food. It shows us that it’s a great move to ask ourselves, where are the fermented foods in our diet? What are your favorite fermented foods? Check out some of the recipes in Eat to Beat Depression and Anxiety that use fermented foods like the kimchi fried rice or all the smoothie recipes that use kefir. I hope this study from Stanford helps you think about how to incorporate fermented foods in your diet and understand some of the science of why that’s so important. It’s such a cool time to be thinking about Nutritional Psychiatry and how what we eat affects things like inflammation, because more than ever, we now know processes like inflammation, diversity in the microbiome significantly impact your brain health and your mental health.

Drew Ramsey, MD

Drew Ramsey, M.D. is a psychiatrist, author, and farmer. He is a clear voice in the mental health conversation and one of psychiatry’s leading proponents of using nutritional interventions. He is an assistant clinical professor of psychiatry at Columbia University College of Physicians and Surgeons.

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  1. Thank you for this Dr. Ramsey. I look forward to introducing these foods to my diet and the study of the rationale for their help with brain functioning.

  2. Drew awesome article! I love the fact that you are physician and farmer, provides lots of Cred!
    Arthur Culbert, Ph.D,
    Children’s author/ Urban farmer

  3. Hi Dr Ramsey – thanks for sharing this. Any ideas or info you can share for those of us who get migraines if we attempt kefir or kimchi? (I’ve read it can be dangerous to keep trying since the migraines may signal a sensitivity) Or small-step fermented foods we could try instead? (If it’s covered in your book, please feel free to reference where to check!) Thanks in advance!

    1. Hey Kate, definitely listen to your body. Is it fermented foods that trigger the migraines or is it specifically kefir or kimchi? There are lots of other fermented foods like miso, sauerkraut, natto, pickles etc. Good luck!

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