LONDON, July 21: Humans have enjoyed fermented foods like kefir, kimchi, sauerkraut, and kombucha for centuries, but only recently are scientists starting to explore their health benefits. These diverse foods share a common process—fermentation—that has been used historically to preserve and enhance food.

"Every culture has its own fermented foods," explains Gabriel Vinderola, an associate professor of microbiology at the National University of Litora in Argentina. "Today, fermentation is expanding globally, with thousands of varieties produced industrially."

While industrial-scale fermentation can avoid the need for chemical preservatives, it can introduce additives like salt, sugar, and artificial sweeteners. Researchers at Kings College London found that nearly one-third of fermented products from UK supermarkets contained these additives, classifying some as ultra-processed despite fermentation’s natural preservation benefits.

Fermentation alters the bioavailability of nutrients, making them more accessible for absorption. The recent surge in interest in fermented foods in the West is partly due to the growing awareness of their impact on gut health and overall well-being.

Fermented foods are created through microbial growth, where bacteria and yeast break down carbohydrates such as starch and sugar. The resulting products, from kimchi to kombucha, offer a range of benefits. Paul Cotter, senior principal research officer at Teagasc Food Research Centre in Ireland, notes that fermentation can produce bioactive compounds like organic acids and peptides that positively affect health.

Live bacteria in fermented foods may help enhance gut microbiota and reduce harmful bacteria. Even fermented foods without live bacteria can offer health benefits due to the production of health-promoting molecules. For instance, sourdough retains prebiotics that support gut health.

Modern diets often lack sufficient fiber and are affected by factors like antibiotics and stress, impacting gut microbiota diversity. "Fermented foods can introduce live microbes into the gut, which may help regulate inflammation and improve immune function," says Vinderola.

Research indicates that fermented foods could play a role in reducing inflammation and improving mental health. A study found that sauerkraut, a fermented cabbage, increased lactic acid bacteria in the bloodstream and activated immune receptors to reduce inflammation. Preliminary research also suggests that fermented foods might alleviate anxiety and depression, though more studies are needed.

Research has shown that fermented foods may influence obesity by affecting appetite-regulating neurotransmitters. While promising, the exact mechanisms remain unclear and further research is required.

Researchers are investigating how to personalize fermented foods to meet individual health needs. Paul Cotter highlights that different kefir varieties might have unique benefits, such as cholesterol control or stress reduction. As understanding improves, producers may better retain beneficial microbes in commercially available products.

Fermented foods can contain amines, which may cause headaches in sensitive individuals, and some mass-produced products may be high in sugar. Unpasteurized fermented foods also carry a risk of contamination, as seen in past outbreaks.

There is limited research on the health benefits of specific fermented foods due to varying bacterial profiles. Yogurt is one of the most studied, but results can vary for other products like kefir depending on the bacterial strains used.

Paul Cotter recommends introducing a variety of fermented foods into your diet gradually to determine which ones suit you best. "It’s essential to eat them regularly for sustained health benefits," he says.

Andres Gomez's research suggests that lifelong consumption of fermented foods may offer lasting benefits for gut health. However, newcomers to fermented foods can still enjoy their benefits by incorporating them into their diets consistently.

In conclusion, while the health benefits of fermented foods are becoming clearer, ongoing research will continue to refine our understanding of their impact and help tailor their benefits to individual health needs.