Between 2001 and 2002, two joint FAO and WHO documents were published with the aim of providing guidelines for assessing the safety and efficacy of the bacteria generally defined as ‘probiotics' that are used for providing beneficial health effects in humans. These documents were reports of two international meetings of experts convened by the FAO and WHO as a response to the booming activity in both research and product innovation. Ten years later, it is now possible to examine the impact of these documents on the international regulatory framework as well as on the academic world. The most relevant impact is related to the definition of probiotics, which is now used all over the world as well as gained consideration in national legislations. However, there is still a misuse of the definition due to confusion between the use of beneficial bacteria in food and pharmaceutical-like products. In the European Union, the FAO/WHO documents are currently used as a regulation benchmark for the evaluations by the European Food Safety Authority. In the meantime, the need for a correct and internationally acknowledged taxonomic identification, as required by these documents, has been accepted by both scientists and regulatory authorities, improving the quality of the area. A positive evaluation of the impact of these guidelines can then be done after 10 years, even if their use is still partial.