A panel of scientific experts* assembled in London, UK, on October 23, 2013 to discuss the scope and appropriate use of the term ‘probiotic.’

The International Scientific Association for Probiotics and Prebiotics (ISAPP) organized the meeting to review the relevance of the 12-year-old FAO/WHO definition of probiotics: “Live microorganisms which when administered in adequate amounts confer a health benefit on the host” (FAO/WHO 2001).

This consensus panel was motivated by these recent developments:

  • In the European Union, in the absence of approved health claims for probiotic foods, the word ‘probiotic’ is considered a health claim. Consequently, several countries have determined that the word can no longer be used on foods. The panel wanted to consider this decision in the context of amassed evidence on probiotic health effects.
  • Fecal microbial transplants are being used for treatment of conditions linked to aberrant gut microbiota. The panel considered whether such preparations of live microorganisms should be considered within the scope of probiotics.
  • Native human colonizing microbes are being identified as potential novel probiotics. The panel considered whether such live microorganisms should be considered within the scope of probiotics.

The conclusions of the panel were published in June 2014 as an open access paper in Nature Reviews Gastroenterology and Hepatology.

Panel conclusions:

  • The panel agreed that the FAO/WHO definition for probiotics was still relevant, but advised a minor grammatical correction: “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”.
  • The panel considered the general benefit of supporting a healthy digestive tract was supported by evidence gathered on a large number of different probiotic strains representing commonly studied species, such as a variety of Lactobacillus and Bifidobacterium species. “Supporting a healthy digestive tract” includes a broad array of physiological and clinical endpoints, ranging from normalizing intestinal transit to improving gut barrier function, reducing intestinal symptoms, and preventing and treating intestinal diseases. In the panel’s opinion, calling a product containing a minimum level of one of these well-studied species ‘probiotic’ is justified, even in the absence of strain-specific studies. However, any specific claim beyond “contains probiotics” must be further substantiated.
  • The panel discussed whether certain microbial products fit under the framework of ‘probiotic’:
  1. ‘Live cultures’, traditionally associated with fermented foods, were determined to be outside the framework of probiotic if they were undefined and if there were no proven health benefits associated with them. Traditional fermented foods are certainly components of a healthy diet, and the microbes associated with them may impart health benefits. But there must be a convincing level of evidence to support their health effects to be considered ‘probiotics’. Note that the yogurt starter bacteria, Lactobacillus bulgaricus and Streptococcus thermophilus are considered to be probiotics due to the evidence that they help alleviate symptoms of lactose maldigestion.
  2. Undefined, fecal microbiota transplants are not considered to be probiotics.
  3. New commensals and consortia comprising defined strains from human samples, with adequate evidence of safety and efficacy, are probiotics.

This Consensus Statement provides updates to the probiotic concept that reflect important developments in human microbiota research, such as fecal microbial transplants, as well as the evidence on probiotic efficacy that has amassed since 2001.


*Panel of scientific experts:

Glenn Gibson, Chair, University of Reading, UK; Colin Hill, Alimentary Pharmabiotic Centre, Ireland; Roberto Berni Canani, University of Naples Federico II, Italy; Harry Flint, University of Aberdeen, Scotland; Francisco Guarner, University Hospital vall d’Hebron, CEBERehd, Barcelona, Spain; Dan Merenstein, Georgetown University, USA; Lorenzo Morelli, Università Cattolica del Sacro Cuore, Piazenca, Italy; Bruno Pot, Institut Pasteur – Lille, France; Gregor Reid, University of Western Ontario, Canada; Seppo Salminen, University of Turku, Finland; and Mary Ellen Sanders, ISAPP Executive Science Officer, USA. Philip Calder (UK), was unable to be present at the meeting in person, but participated fully in developing the conclusions from the discussion and in preparation of the manuscript.



1. Hill C, Guarner F, Reid G, Gibson GR, Merenstein DJ, Pot B, Morelli L, Canani RB, Flint, HJ, Salminen S, Calder PC, Sanders ME. (2014).  The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature Rev Gastro Hepatol. doi: 10.1038/nrgastro.2014.66
2. Food and Agricultural Organization of the United Nations and World Health Organization. Health and nutritional properties of probiotics in food including powder milk with live lactic acid bacteria. (2001).