A UK-based specialist in medical microbiology has warned of the risk that probiotic bacteria – found in some fermented foods and supplements – may confer resistance to antibiotics.
In an article for The Conversation on the health implications of consuming fermented foods and yoghurts, Manal Mohammed, a lecturer at the University of Westminster, writes: “Probiotic bacteria can carry genes that confer resistance to antibiotics. These antibiotic resistance genes may pass to other bacteria found in the food chain and gastrointestinal tract via horizontal gene transfer. The most common antibiotic resistance genes carried by fermented foods are against erythromycin and tetracycline, which are used to treat respiratory infections and some sexually transmitted diseases.
She also cites research which identified resistant probiotic strains in supplements, which, she argues, “could lead to resistance to several common types of antibiotics used to treat serious bacterial infections“.
Commenting on popular fermented and probiotic food products, Mohammed says that probiotic Lactobacilli bacteria in kefir “carry resistance to numerous antibiotics”. And she quotes another study in which lactic acid bacteria in dairy products were shown to be resistant to certain important antibiotics.
While acknowledging that fermented foods do offer “a wide variety of health benefits”, Mohammed warns that for some people they “could cause serious health problems”.