Fermented foods like yogurt, kimchi, sauerkraut, and kefir may help lower inflammation in the body by increasing one’s gut bacteria diversity, according to a new study from the Stanford School of Medicine. The same is true for fermented beverages and liquid products like kombucha tea and fermented vegetable brine drinks, according to the researchers, who compared the effects of a diet rich in fermented foods with one that contained high amounts of fiber.
Fermented foods and drinks were very common before the development of refrigeration. Milk products, for example, were first fermented into beverages like kefir and foods like yogurt before they were consumed, with unfermented milk products only growing in popularity when refrigeration became widely available. A recent study linked this change in how dairy is consumed with a negative impact on human health.
The issue of fermented foods and beneficial, diverse gut bacteria extend beyond just dairy, however. A healthy gut microbiome has been linked with everything from lowered inflammation to protective effects on one’s mental health, lowered odds of developing certain autoimmune conditions, and increased protection against things like hypertension.
Given the increasingly apparent role gut bacteria play in human health, it’s no surprise that many people are looking for ways to reliably and effectively improve their own gut microbiome. Probiotic supplements are one popular option but have often been criticized as less than useful due, in part, to the need to keep them properly refrigerated at all times.
According to the researchers behind this new study, it turns out that consuming fermented foods and drinks is all it takes to noticeably improve the diversity of one’s gut bacteria, with greater amounts of consumption leading to more notable changes.
The research involved 36 adult participants who were described as healthy. These participants were tasked with spending 10 weeks eating a diet that was either high in fiber or high in fermented foods. The fermented-food group benefitted most in terms of gut bacteria diversity, according to the study, which also found that blood markers for inflammation also decreased in these participants.
The participants who consumed a high-fiber diet didn’t experience the same decrease in inflammation markers, the study notes, despite the researchers’ anticipation that the fiber increase would have a greater impact on gut bacteria. It would seem that for those who want to increase their gut bacteria diversity and potentially improve their health, a focus on fermented foods, not short-term high-fiber intake, is ideal.