Probiotics are microbes that are claimed to promote health and well-being when added to foods. However, the European Food Safety Authority (EFSA) has so far advised negatively about health claims for probiotics. Companies and scientists have protested against these rejections, sometimes in vigorous language. I argue that EFSA could not have acted differently, given EU regulations and the lack of convincing evidence for some of the claimed effects of probiotics on human health and well-being. One EU regulation that makes it hard to demonstrate the benefits of probiotics is the prohibition of medical claims, i.e. claims that a food prevents or cures a disease. If this prohibition did not exist, manufacturers of nutritional treatments might circumvent the costly procedures required for drugs, and market their products to ill people without thorough proof that they are effective and safe. However, the prohibition is also a legal fiction, because promotion of health and prevention of disease is largely the same thing. EFSA has recently indicated that it will allow health claims based on the ability of probiotics to reduce infections. To a certain extent, this abolishes the distinction between health claims and medical claims. It remains to be seen if probiotics producers can convince EFSA that their products prevent or cure infections and other diseases in humans.