Fermented foods, such as kimchi (a traditional Korean dish similar to pickles, primarily made of cabbage), cheese, and kefir, have become increasingly popular due to their claimed benefits for gut health, including improved weight management and heart health. However, these foods rich in beneficial bacteria may not be suitable for everyone. In this regard, a recent study conducted by Ohio State University revealed that some fermented foods contain antibiotic-resistant bacteria, which can lead to vomiting, diarrhea, or even sepsis. One of these foods was shown to contain a strain of Weissella, associated with infections of the heart lining and bones.
Despite the belief that fermented foods boost the immune system, individuals consuming them may already be unwell or elderly, making them more susceptible to these bacteria. Bahi van de Boor, a nutritionist and spokesperson for the British Nutrition Foundation, told MailOnline: "In this scenario, it is safe to consume supplements of certain probiotic strains to restore gut health." She also warned that "some fermented foods, such as aged cheeses and fermented soy products, are high in histamine, which can lead to symptoms including headaches, rashes, and digestive problems for those with histamine intolerance."
Van de Boor explained: "Fermented foods have recently become very trendy, but ultimately there is stronger evidence for the health benefits of consuming whole grains and legumes five times a day instead of large amounts of kimchi." Dr. Manal Mohamed, a senior lecturer in medical microbiology at the University of Westminster, noted that "some people may experience severe bloating, which can be very painful." She advised individuals with weakened immune systems, pregnant women, infants, and individuals with digestive disorders to avoid fermented foods.
