The Fridge Myth

Image of a thermometer

The Myth:
"The best probiotics are kept in the fridge."

Research says:
Of the 10 most researched probiotic supplements worldwide, only 1 requires refrigeration.


Probiotics can be deemed to be the ‘best’ by a number of different criteria, but the most impressive standard of quality is considered to be a clinical trial conducted using gold standard techniques. It is quite a challenge to sift through all the available (and ever growing) research and reliably pinpoint the most researched probiotics in the world, but the top 10 are certainly amongst the following strains and supplements: L. rhamnosus GG1S. boulardii2L. plantarum 299v3B. infantis 356244L. reuteri DSM 179385B. lactis BB-12®6L. acidophilus NCFM®6L. acidophilus La-56; also the combination of L. reuteri RC-14® and L. rhamnosus GR-1®6, and the probiotic formulation known as VSL#37. These strains are commercially available on the world market, and if we look at the finished products, (eg. L. plantarum GG is most widely available as the American product Culturelle, S. boulardii is most widely available as Florastor, and so on), then we see that of these probiotic supplements only VSL#3 is recommended to be stored in the fridge*.

There are a few reasons why refrigeration is less of a requirement these days. These include improvements in freeze drying techniques8 and discovery of strains which are naturally more robust within themselves, due to intensive investment in research and development into probiotics.

Whilst some good quality probiotics may be kept in the fridge, it is clear that this storage method does not render a probiotic superior, nor denote the best.

*Some of the other strains may require refrigeration after opening depending on format, packaging, and the heat/humidity in local environment. Contact manufacturer for guidance.

Look out for:

A well researched probiotic range, regardless of its recommended storage.

Further Reading

Health professionals can read research on Lactobacillus rhamnosus GR-1® and Lactobacillus reuteri RC-14® and more about Lactobacillus acidophilus NCFM®

This myth has been busted by Megan Crowch, BSc (Hons) Physiology, Herbal Medicine Diploma (IRH practicing member).


  1. Cruchet et al. (2015) The use of probiotics in pediatric gastroenterology: a review of the literature and recommendations by Latin-American experts. Paediatr Drugs; 17, 3: 199-216.
  2. McFarland (2010) Systematic review and meta-analysis of Saccharomyces boulardii in adult patients. World J Gastroenterol; 16, 18: 2202-22.
  3. Ducrotté et al. (2012) Clinical trial: Lactobacillus plantarum 299v (DSM 9843) improves symptoms of irritable bowel syndrome. World J Gastroenterol; 18, 30: 4012-8.
  4. Whorwell et al. (2006) Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome. Am J Gastroenterol; 101, 7: 1581-90.
  5. Schreck Bird et al. (2016) Probiotics for the Treatment of Infantile Colic: A Systematic Review. J Pharm Pract pii: 0897190016634516. [Epub ahead of print]
  6. Yuan Kun Lee et al. (2009) Handbook of Probiotics and Prebiotics, 2nd Edition Wiley: New Jersey
  7. Shen et al. (2014) Effect of probiotics on inducing remission and maintaining therapy in ulcerative colitis, Crohn’s disease, and pouchitis: meta-analysis of randomized controlled trials. Inflamm Bowel Dis; 20, 1: 21-35.
  8. aconelli et al. (2015) Drying process strongly affects probiotics viability and functionalities. J Biotechnol; 214, 17-26.

You might also be interested in: 

The Research Myth 
The Antibiotic Myth 
The Strain Myth 
The Survival Myth 
The Numbers Myth 
The Cure-All Myth 
The Billions Myth 
The Food Myth