ExeGi's Response to Alfasigma’s "Dear Doctor" Letter

On January 31, 2019 Alfasigma published a “Dear Doctor Letter” which it posted on its website and distributed to healthcare professionals. To the credit of Alfasigma, they acknowledge in the letter that they were found liable by a Federal Jury for lying to consumers and patients about their knock off VSL#3* product. However, the letter now suggests that the reader should overlook their prior lies and now trust their new representations about the knock off VSL#3. The letter contains material misrepresentations and falsities, similar to those statements for which they were previously found liable. 

Here are the facts:

  • Alfasigma is contesting the verdict through post-trial motions, as is common in civil trials. We will await further decisions by the Court but for now the unanimous 9 person jury verdict contains the prevailing judgment.
  • Alfasigma claims its knock off VSL#3 contains the same 8 strains of bacteria as the original product manufactured by Danisco (currently sold as Visbiome containing the original De Simone Formulation). During the trial, extensive evidence was presented to the jury which established that the knock off only contains 7 strains not the 8 originally found in the real formulation.
  • During the trial, one microbiologist did testify in support of the knock off VSL#3. However, Alfasigma fails to note that not one medical doctor testified in support of their product. Conversely, three medical doctors, including a world renowned pediatric gastroenterologist from Harvard, testified that the knock off VSL#3 could not be trusted to be equivalent to the original formulation. Two additional PhD level scientists provided additional support for and data concerning this assertion.
  • The sole microbiologist who testified on behalf of Alfasigma confirmed that his conclusions were not based on an analysis of commercially available VSL#3 products.
  • The sole evidence published of “equivalence” between knock off and original VSL#3, Douillard et al 20181, was ostensibly refuted by the authors when it was pointed out that the products they tested were not commercially available VSL#3 product but rather individual strains given to them by the brand owner. The correction to the article, sited in the Alfasigma letter, can be found here https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6117072/
  • Alfasigma fails to accept the overwhelming scientific evidence which clearly establishes that genetic similarity of probiotic strains does not equal functional equivalence. Two strains with identical genetics, within detectable limits, can act extremely differently depending on how they are produced2,3,4,5,6,7. Extensive data was presented on this point to the jury at trial yet Alfasigma continues to try to propagate this falsity.
  • Alfasigma baldly asserts that “Studies previously performed on the Danisco product can be relied on to show the efficacy and safety of the Italian-made product.” We invite the recipients of this message (healthcare professionals and patients) to ask Alfasigma upon what clinical science they are making this assertion? As of the publication of this blog, and to our best knowledge, there have been no human, or animal, bridging studies establishing the functional equivalence of original vs knock off VSL#3.

Patient and healthcare providers looking for the original De Simone Formulation can find this product in Visbiome and Visbiome Extra Strength. Visbiome contains the same proprietary probiotic formula, and is produced at the same production facility, using the same production methods, as the probiotic previously sold under the name VSL#3*, until July 2016.

*VSL#3® is a registered trademark and is manufactured exclusively for, VSL Pharmaceuticals, Inc. Visbiome® is manufactured exclusively for ExeGi Pharma, LLC and is not affiliated with, endorsed by, or distributed by VSL Pharmaceuticals, Inc.


1 Douillard FP, MoraD, Eijlander RT, Wels M, de Vos WM (2018) Comparative genomic analysis of the multispecies probiotic marketed product VSL#3. PLoS ONE 13(2): e0192452. https://doi.org/1 0.1371/journal.pone.0192452

2 Sanders ME, Klaenhammer TR, Ouwehand AC, et al. Effects of genetic, processing, or product formulation changes on efficacy and safety of probiotics. Annals of the New York Academy of Sciences 2014; 1309(1): 1±18.

3 Deepika G, Green RJ, Frazier RA, et al. (2009) Effect of growth time on the surface and adhesion properties of Lactobacillus rhamnosus GG. J Appl Microbiol 107, 1230–1240.

4 Grzesakowiak è, Isolauri E, Salminen S, Gueimonde M. Manufacturing process influences properties of probiotic bacteria. Br J Nutr. 2011 Mar; 105(6):887±94. doi: 10.1017/S0007114510004496 Epub 2010 Nov 9. PMID: 210592 

Saarela MH, Alakomi HL, Puhakka A, Matto J. Effect of the fermentation pH on the storage stability of Lactobacillus rhamnosus preparations and suitability of in vitro analyses of cell physiological functions to predict it. J Appl Microbiol 2009; 106(4): 1204±12. doi: 10.1111/j.1365-2672.2008.04089.x PMID:19191949

6 Vinderola, et al. Cell viability and functionality of probiotic bacteria in dairy products. Frontiers in Microbiology. May 2011. doi: 10.3389/fmicb.2011.0007 

7 Soto C. Lactobacillus plantarum as source of conjugated linoleic acid: Effect of pH, incubation Temperature and inulin incorporation. J Biochem Tech (2013) 5(1):649-653.