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Fermented foods hold the key to a diverse gut microbiome, which enables your immune system to mount its best defense against pathogens.
This gut-immune relationship was shown by a study of 100 Covid-19 patients. Researchers found that people with lower levels of certain gut bacteria had more severe illness, higher inflammation, and more tissue damage.
“Your immune response is all about balance,” says Pedre. It turns up the inflammation level while fighting a pathogen, and then turns it down once the invader is defeated—if it’s working properly. When the inflammatory response continues for too long, it damages tissues, prolongs symptoms, and may cause chronic health conditions.
Why Fermented Foods?
Fermented foods can whip the immune system into better shape, according to a study at the Stanford School of Medicine that tested two types of diets for 10 weeks. One diet was high in fermented foods, while the other was high in fiber.
Fermented foods increased the diversity of microbes in the gut and decreased levels of 19 inflammatory markers in the blood. Fiber helped to maintain beneficial gut bacteria and improve their performance.
Pedre explains it this way: “It’s basically saying, ‘Hey, if you’ve got the right amount of good guys in your gut, they’re going to help protect you from having a runaway inflammatory immune response that could have you dealing with the worst consequences of any infection that you get.’”
Feed Your Microbiome
Eat a variety of fermented foods, says Pedre, as each food contains different beneficial bacteria. Also eat plenty of high-fiber foods—such as leafy greens, onions, Jerusalem artichokes, and garlic—that support healthy gut microbes.
One serving of a fermented food is about one-quarter cup. But you may need to start small if your gut is in poor shape—perhaps a teaspoon of sauerkraut juice per day. Be consistent and patient, as it can take a month or more for gut bacteria to be replenished.
If you’ve recently taken antibiotics, add a supplement designed to survive stomach acid that contains a variety of probiotic strains. Doses range from 2.5 billion to 225 billion colony forming units (CFUs) per day.
Our Favorite Fermented Foods
Eat a variety of these:
- Kefir or yogurt (plain, plant-based or organic, grass-fed dairy)
- Sauerkraut (cultured)
- Pickles (cultured)
- Fermented cottage cheese
- Kimchi and other fermented vegetables