STANFORD, Calif. — Eating yogurt can help tackle arthritis, type 2 diabetes, and even stress, according to what scientists are calling a “stunning” find. Researchers from Stanford University say fermented foods like yogurt, kefir, cottage cheese, kimchi, and kombucha tea boosts good gut bacteria and seems to help prevent inflammation — which can trigger diabetes and arthritis.

Study authors add eating these foods led to an increase in overall microbial diversity in the gut, with stronger effects from larger servings. The levels of 19 inflammatory proteins – which are markers of inflammation – also decreased.

One of these proteins, called interleukin 6, has a connection to conditions such as rheumatoid arthritis, type 2 diabetes, and chronic stress.

“This is a stunning finding,” says Justin Sonnenburg, PhD, an associate professor of microbiology and immunology, in a university release. “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.”

High-fiber diets ‘universally beneficial’

Stanford researchers found that eating a diet high in fermented foods such as kimchi increases the diversity of gut microbes, which is associated with improved health.
(Credit: Nungning20/Shutterstock/Stanford Medicine)

The researchers made their discovery during a study comparing the effects of high-fiber and high-fermented food diets. While high-fiber diets have a link to lower rates of mortality, none of the 19 inflammatory proteins decreased in participants eating a high-fiber diet. Foods high in fiber include legumes, seeds, whole grains, nuts, vegetables, and fruits. On average, the diversity of their gut microbes did not change for high-fiber eaters.

“We expected high fiber to have a more universally beneficial effect and increase microbiota diversity,” explains Dr. Erica Sonnenburg, a senior research scientist in basic life sciences, microbiology, and immunology at Stanford. “The data suggest that increased fiber intake alone over a short time period is insufficient to increase microbiota diversity.”

“We wanted to conduct a proof-of-concept study that could test whether microbiota-targeted food could be an avenue for combatting the overwhelming rise in chronic inflammatory diseases,” adds Dr. Christopher Gardner, professor of medicine at Stanford.

The researchers analyzed blood and stool samples collected during a three-week pre-trial period, the 10 weeks of the diet, and a four-week period after the diet when the participants ate as they chose. Those who increased their consumption of fermented foods showed similar effects on their microbiome diversity and inflammatory markers which chimed with previous research showing that short-term changes in diet could change the gut microbiome.

Fiber also helps break down carbohydrates

The results also showed that greater fiber intake led to more carbohydrates in stool samples, pointing to incomplete fiber digestion by gut microbes. The researchers say their findings were consistent with other studies which suggested that the microbiome of people living in the industrialized world lacks fiber-degrading microbes.

“It is possible that a longer intervention would have allowed for the microbiota to adequately adapt to the increase in fiber consumption,” Erica Sonnenburg suggests. “Alternatively, the deliberate introduction of fiber-consuming microbes may be required to increase the microbiota’s capacity to break down the carbohydrates.”

The researchers now plan to conduct studies in mice to investigate the molecular mechanisms behind how diets change the microbiome and reduce inflammatory proteins. They also aim to test whether high-fiber and fermented foods work together to influence the microbiome and immune system.

Another goal is to look into whether the consumption of fermented food decreases inflammation or improves other health in patients with immune and metabolism diseases, and in pregnant women and older people.

“There are many more ways to target the microbiome with food and supplements, and we hope to continue to investigate how different diets, probiotics and prebiotics impact the microbiome and health in different groups,” Dr. Justin Sonnenburg concludes.

The findings appear in the journal Cell.

SWNS writer William Janes contributed to this report.

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