Microbiology: Categorize probiotics to speed research

Journal name:
Date published:
Published online

As chairman of a panel convened in 2001–02 by the United Nations and the World Health Organization to establish guidelines for the use of probiotics, I am dismayed by recent regulatory changes in Europe and the United States.

These have led the European Food Safety Authority (EFSA) to override peer-reviewed studies in prestigious journals, and the US Food and Drug Administration (FDA) now requires an Investigational New Drug Application to be filed for probiotic foods or supplements that are intended to prevent or treat disease. The former has led to many negative ramifications for probiotic research and development in Europe, and the latter has halted research on probiotics at the US National Institutes of Health.

With the market for probiotics already exceeding US$30 billion, and the Human Microbiome Project uncovering new candidate probiotic strains, I propose that the major agencies (at least EFSA and the FDA), together with international probiotic experts, create a simple categorization 'tree' system that would improve the adjudication process and be more informative for consumers. Every probiotic would need a set of minimal requirements, including strain designation and shelf life.

The lowest category would include yogurts that reduce adverse effects in lactose-intolerant individuals; other 'category 1' products would require only minimally documented studies in humans.

For the middle category, at least two randomized controlled studies would be needed to show how the probiotic works, with the results published in peer-reviewed journals. This could include probiotic yogurts that, in addition to the lactose-digestion effect, reduce gut discomfort or increase intestinal transit time, as well as other probiotic products that counter adverse effects of antibiotics or restore microbial homeostasis to the vagina or mouth.

The third category would be reserved for products targeting vulnerable people such as infants and the elderly. It would include recombinant strains and species not previously used in foods and supplements — for example, bacteria producing neurochemicals that could improve cognitive function or memory. Strict adjudication would be required for products in category 3.

Author information


  1. Lawson Health Research Institute and University of Western Ontario, London, Ontario, Canada.

    • Gregor Reid

Corresponding author

Correspondence to:

Author details

Additional data