Researchers at Stanford University have found that consuming fermented foods such as yogurt, sauerkraut, and kombucha tea creates a rich diversity in the gut microflora, thereby diminishing inflammation. The research study was published in the journal Cell.
A team of immunologists led by Justin Sonnenburg tracked 36 healthy adult participants over the course of ten weeks. Each individual was randomly assigned to be in the fermented food group or given a high-fiber diet. The researchers analyzed blood and stool samples to examine changes in the composition of the gut microflora and inflammatory biomarkers.
Four distinct immune cell types showed a dip in activation status in the cohort that consumed fermented foods. They also had lower levels of 19 inflammatory proteins in circulation, including interleukin-6, a cytokine whose elevated levels have previously been associated with arthritis and chronic stress. The same anti-inflammatory effects were not observed in those who kept to a high-fiber diet.
According to the researchers, these results are, in part, an effect of having more microbial diversity in the gut. Low diversity of the gut microflora has been linked to obesity and diabetes in previous studies.
“This is a stunning finding,” commented Sonnenburg. “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.”
Interestingly, these findings contradict existing hypotheses that a high fiber intake can increase microbiota diversity.
In follow-up studies, the team plans to take a closer look at the molecular mechanisms underlying the influence of diet on inflammatory markers. In addition, they seek to understand whether eating a combination of high-fiber and fermented foods can have a synergistic effect on health and well-being.