VSL#3 and the De Simone Formulation: What Published Sources Say
VSL#3 Alternatives in the UK:
The De Simone Formulation Explained
UK consumers researching alternatives to VSL#3 often encounter the term "De Simone Formulation". This guide sets out what the term means, what ECCO and the AGA have said about it, and which products are on the UK market in 2026.
VSL#3® is a registered trademark of VSL Pharmaceuticals Inc. and Actial S.r.l. Vivomixx® is a registered trademark of Mendes SA. Visbiome® is a registered trademark of ExeGi Pharma. CDS22-formula is manufactured by EOS2021 S.r.l. These are independent companies and are not affiliated with each other.
Probiotic.co.uk and CDS22-formula are not affiliated with, endorsed by, sponsored by, connected to or distributed by the holders of the VSL#3, Vivomixx or Visbiome trademarks. Those brand names are referred to on this page for identification and historical reference only. CDS22-formula is a separate product sold in competition with them. Nothing on this page should be read as a claim that CDS22-formula is, continues to be, or is a version of any of those branded products.
This page is commercial in nature. Probiotic.co.uk sells CDS22-formula and is not a neutral party on this subject. Statements attributed to ECCO, the AGA, courts or manufacturers are reported as those parties have published them. Readers should consult the linked primary sources directly rather than rely on this summary, and should obtain current specifications from the relevant manufacturer before drawing any conclusion about a product.
ECCO stated in October 2023 that the De Simone Formulation was sold under the VSL#3 brand until 2016, and that after 2016 the product sold as VSL#3 no longer contains it. UK consumers looking for that formulation today are therefore looking for a product other than current VSL#3. CDS22-formula is one product on the UK market whose manufacturer, EOS2021 S.r.l., states it contains the De Simone Formulation, produced from the same original master cell bank and listed on the current UK label under NCIMB codes. This guide sets out the primary sources so you can check that for yourself.
| Question | Stated position | Source |
|---|---|---|
| What has ECCO said about VSL#3 and the De Simone Formulation? | ECCO stated in October 2023 that after 2016 the product sold as VSL#3 no longer contains the De Simone Formulation. | ECCO official statement, October 2023 |
| What does the CDS22 manufacturer state about its formulation? | EOS2021 S.r.l. states that CDS22-formula contains the De Simone Formulation. This is a manufacturer statement, not an independent finding. | Manufacturer's own statement, cds22.com. Not an independent source. |
| Which clinical guideline names the formulation? | The AGA 2024 pouchitis guideline names the De Simone Formulation as the probiotic used in the trials it reviewed. | Barnes et al., Gastroenterology 2024, PMID 38128971 |
| What did the US false-advertising litigation find? | A US jury found the post-2016 VSL#3 sold in the United States was not the same formulation, making claims of equivalence false and misleading. Affirmed by the Fourth Circuit in 2021. A US ruling under US law, concerning the US-marketed product. | US Court of Appeals, Fourth Circuit, 2021 |
| Is Vivomixx Neo the same product as the earlier Vivomixx 450? | Mendes SA introduced Vivomixx Neo in 2024 as a separate product from the earlier Vivomixx 450. Consumers should check the current label and manufacturer information. | Probiotic.co.uk comparison guide |
Trial and publication figures relate to the De Simone Formulation as described in the published literature and are as stated by the manufacturer, EOS2021 S.r.l. No clinical trial has been conducted on CDS22-formula under that product name. These figures are not a claim that CDS22-formula treats, cures or prevents any condition.
What Does "De Simone Formulation" Mean?
"De Simone Formulation" is the term used in the clinical literature for a specific 8-strain probiotic blend developed by Professor Claudio De Simone, an Italian clinician and researcher. Trials using this blend were published in Gastroenterology and Gut from 2000 onwards. The 2024 ESPEN attribution paper in Clinical Nutrition was written specifically to clarify how this formulation should be attributed in published research.[2a]
ECCO states that until 2016 this formulation was sold under the VSL#3 brand, and that a commercial separation then took place between Professor De Simone and the VSL#3 brand owner. According to ECCO, the VSL#3 brand name continued, but the product sold under it after 2016 no longer contains the De Simone Formulation.[2]
In parallel US litigation, a Maryland jury found in 2018 that claims of equivalence between the post-2016 US VSL#3 product and the earlier formulation were false and misleading under the US Lanham Act. The Fourth Circuit affirmed that verdict in February 2021, while holding part of the resulting injunction overbroad and vacating it in part.[1] That litigation concerned the product marketed in the United States and was decided under US law. It is not a ruling of any UK court and it does not determine the composition of any product currently sold in the UK.
Readers should consult the primary sources directly rather than rely on this summary, and should obtain current specifications from the relevant manufacturer before drawing any conclusion about a product. For further background see the De Simone Formulation UK reference.
Brand History Timeline: 2016 to 2026
Commercial Separation
Professor De Simone separates from Actial S.r.l. In the subsequent US litigation, the Fourth Circuit recorded that ownership of the formulation remained with Professor De Simone while the VSL#3 trade name remained with the former licence partner. ECCO states that from this date the VSL#3 brand and the De Simone Formulation should be treated as distinct.
Vivomixx Neo Introduced
Mendes SA launches Vivomixx Neo under the Vivomixx brand name. Mendes SA presents Vivomixx Neo as a separate product from the earlier Vivomixx 450, which was discontinued in 2025. UK consumers should not assume that a shared brand name means a shared formulation, in either direction. Check the current label and manufacturer information. See our Vivomixx Neo background guide for the detail.
CDS22-Formula Enters the UK Market
CDS22-formula is launched by EOS2021 S.r.l. Its manufacturer states that it contains the De Simone Formulation, produced from the same original master cell bank, at 450 billion CFU per sachet. The current UK label lists eight strains under NCIMB codes, set out in the table below. These are the manufacturer's own statements about its product and Probiotic.co.uk has not independently verified them.[3] We are not aware of another product currently marketed in the UK on the same basis, though consumers should verify the position for themselves.
What ECCO and the AGA Have Published
Two clinical bodies have published material that refers to the De Simone Formulation by name. Both are set out below in their own terms. Neither body endorses any retail product, and neither has any connection to Probiotic.co.uk.
The European Crohn's and Colitis Organisation published a statement addressing how the VSL#3 references in its 2017 IBD guidelines should be read. ECCO states that until 2016 the De Simone Formulation was sold under the VSL#3 brand, and that after 2016 the product sold as VSL#3 no longer contains it.[2]
ECCO's stated position is therefore that where its 2017 IBD guidelines refer to VSL#3, those references should be read as relating to the De Simone Formulation. Readers should consult the ECCO statement directly rather than rely on any retailer's summary, including ours.
AGA 2024 pouchitis guideline
The American Gastroenterological Association's 2024 clinical practice guideline on the management of pouchitis and inflammatory pouch disorders (Barnes et al., Gastroenterology 2024;166(1):59-85, PMID 38128971) identifies the De Simone Formulation by name as the probiotic used in the trials it reviewed, and states that the probiotic evidence for preventing recurrent pouchitis is limited to that formulation. That recommendation is conditional and based on low-certainty evidence.
Note: these guideline references relate to the De Simone Formulation as a studied formulation. They are not an endorsement of CDS22-formula or of any other retail product, and no clinical trial has been conducted on CDS22-formula under that name. Anyone using these guidelines to inform a clinical decision should verify formulation identity against current manufacturer documentation and discuss it with their clinician.
The Current CDS22-Formula UK Label, Strain by Strain
The table below sets out the eight strains as they appear on the current CDS22-formula UK label, alongside the pre-2016 names used in the published research.
We make no assertions about the composition of current VSL#3 or Vivomixx Neo. We have not tested those products and their strain designations and sourcing cannot be independently verified by us from public sources. Those columns are therefore marked "Not asserted here". Anyone wanting to compare products should obtain current specifications directly from each manufacturer.
| Name used in the pre-2016 research | Current CDS22-formula UK label (NCIMB code) | Current VSL#3 | Vivomixx Neo |
|---|---|---|---|
| Streptococcus thermophilus | NCIMB 30438 | Not asserted here | Not asserted here |
| Bifidobacterium breve | NCIMB 30441 | Not asserted here | Not asserted here |
| Bifidobacterium longum (reclassified) | B. animalis subsp. lactis NCIMB 30435 | Not asserted here | Not asserted here |
| Bifidobacterium infantis (reclassified) | B. animalis subsp. lactis NCIMB 30436 | Not asserted here | Not asserted here |
| Lactobacillus acidophilus | NCIMB 30442 | Not asserted here | Not asserted here |
| Lactobacillus plantarum | NCIMB 30437 | Not asserted here | Not asserted here |
| Lactobacillus paracasei | NCIMB 30439 | Not asserted here | Not asserted here |
| Lactobacillus delbrueckii subsp. bulgaricus (reclassified) | L. helveticus NCIMB 30440 | Not asserted here | Not asserted here |
| Cell bank source | Original DSF master cell bank | Not asserted here | Not asserted here |
| Stated position on the De Simone Formulation | EOS2021 S.r.l. states CDS22-formula contains it | ECCO states post-2016 VSL#3 does not contain it | Mendes SA markets Neo as a separate product from Vivomixx 450 |
CDS22-formula NCIMB strain codes are taken from the current UK product label and manufacturer documentation supplied by EOS2021 S.r.l. Probiotic.co.uk has not independently tested any product listed. No composition claim is made here about current VSL#3 or Vivomixx Neo. Strain designations, sourcing and specifications change; always verify against current manufacturer documentation in your market before making any clinical decision, and discuss clinical decisions with a qualified healthcare professional.
How to Check Formulation Identity Yourself
Rather than relying on brand names or on any retailer's summary, including ours, you can check the position yourself using publicly available sources.
- Read the ECCO statement in full. ECCO published its position in October 2023. The attribution question is also addressed in the 2024 ESPEN paper in Clinical Nutrition. Read both directly rather than relying on a summary.
- Check the strain list on the pack. Compare the deposit codes on the current label rather than the brand name on the front of the box. Deposit codes identify specific strains against a public register.
- Check the guideline by its PMID. The AGA guideline is PMID 38128971. Note which formulation and which dose the trials actually used, and in which patient population.
- Read each manufacturer's position in its own words, and treat each as an interested party. EOS2021 S.r.l. publishes its position on CDS22-formula at cds22.com. Request current specifications directly from the manufacturer of whichever product you are considering. Each of these is a commercial statement by a party with an interest in the outcome, including the one we distribute. None is an independent verification. Where a specific claim matters to you, ask the manufacturer for the underlying documentation rather than relying on a website summary.
- Discuss any clinical decision with your GP or gastroenterologist. This page is not medical advice.
The UK Market in 2026
This table sets out the current position and each manufacturer's own stated position on its product.
| Product | Manufacturer's stated position | Status in 2026 | UK Availability |
|---|---|---|---|
| CDS22-formula | EOS2021 S.r.l. states it contains the De Simone Formulation, from the original master cell bank | Current | Available from Probiotic.co.uk |
| Visbiome (US) | ExeGi Pharma states it contains the De Simone Formulation | Current | US market only |
| Original Vivomixx 450 | Was marketed by Mendes SA as containing the De Simone Formulation | Discontinued 2025 | No longer available |
| VSL#3 (current) | ECCO states post-2016 VSL#3 does not contain the De Simone Formulation. Refer to the brand owner for current specifications. | Current | Available in the UK |
| Vivomixx Neo | Marketed by Mendes SA as a separate product from Vivomixx 450 | Current | Available in the UK |
The statements set out above come from published sources. ECCO published a clarification in 2023. A US jury reached a finding under US false-advertising law in 2018, affirmed on appeal in 2021. EOS2021 S.r.l. states that CDS22-formula contains the De Simone Formulation. Probiotic.co.uk sells CDS22-formula and is therefore not a neutral party in this. We have set out the primary sources and links above so that you can read each of them directly, obtain current specifications from the relevant manufacturer, and reach your own view, ideally with your clinician.
The clinical research and guideline references in this guide relate to the De Simone Formulation as a studied formulation. They are not a claim that CDS22-formula treats, cures, or prevents any disease, and no clinical trial has been conducted on CDS22-formula under that product name. CDS22-formula is a food supplement, not a medicine. No authorised health claim is made for it on this page. Probiotic.co.uk sells CDS22-formula and is not a neutral party on this subject.
CDS22-formula from Probiotic.co.uk
450 billion CFU per sachet. Eight strains listed under NCIMB codes. Cold-chain protected. Tracked next-day delivery across the UK from our Lancashire facility.
✓ Shop CDS22-formulaVSL#3 Alternatives in the UK: Common Questions
No. Probiotic.co.uk is an independent UK retailer and the sole exclusive distributor of CDS22-formula for the United Kingdom and Ireland, appointed under written agreement with the manufacturer EOS2021 S.r.l. We have no affiliation, endorsement, sponsorship or distribution relationship with VSL Pharmaceuticals Inc., Actial S.r.l., Mendes SA or ExeGi Pharma. VSL#3 is a registered trademark of VSL Pharmaceuticals Inc. and Actial S.r.l. We refer to those brand names for identification and historical reference only.
Most are looking for the formulation described in the clinical literature as the De Simone Formulation. ECCO stated in October 2023 that this formulation was sold under the VSL#3 brand until 2016 and that after 2016 the product sold as VSL#3 no longer contains it. CDS22-formula is one product on the UK market whose manufacturer, EOS2021 S.r.l., states it contains the De Simone Formulation. Read the ECCO statement in full and obtain current specifications from the relevant manufacturer before deciding.
ECCO stated in October 2023 that after a 2016 commercial separation the product sold as VSL#3 no longer contains the De Simone Formulation. In separate US litigation a Maryland jury found in 2018 that claims of equivalence between the post-2016 US VSL#3 product and the earlier formulation were false and misleading under the Lanham Act, and the Fourth Circuit affirmed that verdict in 2021 while holding part of the resulting injunction overbroad. Those proceedings concerned the US-marketed product under US law and are not a ruling of any UK court.
Both refer to the De Simone Formulation by name rather than to a retail brand. The AGA 2024 pouchitis guideline (Barnes et al., Gastroenterology 166(1):59-85, PMID 38128971) identifies the De Simone Formulation as the probiotic used in the trials supporting its recommendation, and states that the probiotic evidence for preventing recurrent pouchitis is limited to that formulation. ECCO states that the VSL#3 references in its 2017 IBD guidelines should be read as relating to the De Simone Formulation. Neither body endorses any retail product.
The current UK label lists eight strains under NCIMB codes NCIMB 30435 to NCIMB 30442, at 450 billion CFU per sachet. Under updated bacterial taxonomy three organisms were reclassified: the former B. longum and B. infantis are now B. animalis subsp. lactis, and the former L. delbrueckii subsp. bulgaricus is now L. helveticus. These are naming changes rather than changes to the organisms. Probiotic.co.uk makes no assertion here about the composition of any competing product.
Mendes SA introduced Vivomixx Neo in 2024 and markets it as a separate product from the earlier Vivomixx 450, which was discontinued in 2025. Consumers who previously used Vivomixx 450 should check the current Vivomixx Neo label and manufacturer information rather than assuming that a shared brand name means a shared formulation.
Read the ECCO October 2023 statement in full, compare strain names and deposit codes on the current product label rather than relying on the brand name, and request current specifications directly from the manufacturer of whichever product you are considering. Every manufacturer is an interested party, including the one we distribute, so read the primary sources rather than relying on any retailer's summary.
CDS22-formula is available from Probiotic.co.uk, the sole exclusive distributor for the United Kingdom and Ireland. Orders are dispatched from a temperature-controlled facility in Lancashire with cold-chain packaging and tracked next-day delivery across the UK including Northern Ireland. Free cold-chain UK delivery on orders over £65. CDS22-formula is a food supplement, not a medicine.
Related Articles
This guide was prepared by Probiotic.co.uk using the following process. We reviewed the primary sources on the De Simone Formulation, including the AGA 2024 pouchitis guideline (Barnes et al., PMID 38128971), the ECCO statement of 26 October 2023, the 2024 ESPEN attribution paper in Clinical Nutrition, and the published US Fourth Circuit judgment. We cited the AGA guideline by its PubMed identifier (PMID 38128971) and linked it to PubMed. We attributed each statement to the published source that made it, and did not characterise the position of any party that has not published one. We listed the current CDS22-formula strains using the NCIMB codes on the current UK label with a note on the taxonomy reclassification, and we made no assertion about the composition of any competing product. We have not independently tested any product referred to on this page. We checked the content against UK food supplement rules and made no disease-treatment claims for any supplement. Probiotic.co.uk sells CDS22-formula and has a commercial interest in this subject.
Sources
- [1] US Court of Appeals for the Fourth Circuit, February 2021 · caselaw.findlaw.com
- [2] ECCO Official Statement, 26 October 2023 · ECCO statement (PDF)
- [2a] Clarifying Correct Attributions in Scientific Literature, ESPEN, Clinical Nutrition 2024 · doi.org/10.1016/j.clnu.2024.05.022
- [3] EOS2021 S.r.l., manufacturer of CDS22-formula: the manufacturer's own published position. An interested party in the matters described on this page, not an independent source · cds22.com
- [4] Barnes EL et al. AGA Clinical Practice Guideline on the Management of Pouchitis and Inflammatory Pouch Disorders. Gastroenterology 2024;166(1):59-85 · PMID 38128971