Nutritionists Explain Fermented Foods and Who Should Limit Intake

Fermented foods undergo a process in which microorganisms convert carbohydrates into acids, gases, or alcohol, according to Caroline Susie, a registered dietitian and national spokesperson for the Academy of Nutrition and Dietetics. The same process preserves food, alters flavor and texture, and can produce beneficial bacteria, said Amy Goodson, a nutritionist and registered dietitian at The Sports Nutrition Playbook.

Common examples include yogurt, kefir, sauerkraut, kimchi, aged cheeses such as cheddar and parmesan, miso, tempeh, kombucha, soy sauce, authentic sourdough bread, and certain pickles.

Fermented foods can introduce probiotics that support the gut microbiome, the community of microorganisms in the digestive tract. Fermentation can also increase the availability of B vitamins and minerals including calcium and iron, Goodson said. Susie noted emerging research linking certain probiotic strains to effects on mood, anxiety, memory, and attention, though she added that more human studies are needed.

Most people can include fermented foods regularly, the dietitians said. Individuals with histamine intolerance may experience headaches or digestive discomfort, Goodson said. U.S. Centers for Disease Control and Prevention. High sodium levels in items such as sauerkraut, kimchi, and pickles can affect individuals managing hypertension or heart disease, Goodson said.

Susie added that people with small intestinal bacterial overgrowth may experience increased bloating or gas.