Fermented Foods vs. High-Fiber Foods in Your Diet

A diet rich in fermented foods enhances the diversity of gut microbes and decreases molecular signs of inflammation, according to researchers at the Stanford School of Medicine. These researchers conducted a clinical trial with 36 healthy adults. The participants were randomly assigned to a 10-week diet that included either fermented or high-fiber foods. Each type of diet had different effects on the gut microbiome and the immune system.

The study showed that consuming fermented foods like kimchi, kefir, yogurt, vegetable brine drinks, fermented vegetables, and kombucha tea helped increase microbial diversity. Consuming larger portions of fermented foods resulted in stronger effects.

“This is a stunning finding,” said Justin Sonnenburg, Ph.D., an associate professor of microbiology and immunology. “It provides one of the first examples of how a simple change in diet can reproducibly remodel the microbiota across a cohort of healthy adults.”

In addition, certain immune cells showed less activation in the fermented foods group. The levels of 19 inflammatory proteins in the blood also decreased. One of the proteins interleukin 6, has been associated with conditions like rheumatoid arthritis, chronic stress, and Type 2 diabetes.

“Microbiota-targeted diets can change immune status, providing a promising avenue for decreasing inflammation in healthy adults,” said Christopher Gardner, Ph.D., the Rehnborg Farquhar Professor and director of nutrition studies at the Stanford Prevention Research Center. “This finding was consistent across all participants in the study who were assigned to the higher fermented food group.”