About High-count multi-strain blend (De Simone formulation)
An eight-strain preparation of lactobacilli, bifidobacteria and Streptococcus thermophilus supplied at 450 billion CFU or more per sachet — roughly a hundred times the count of a typical retail probiotic.
This formulation has the best evidence of any probiotic blend, and it is confined to two intestinal conditions: maintaining remission in pouchitis after colectomy, and as an add-on in mild to moderate ulcerative colitis, where guidelines in several countries mention it. It also comes with a cautionary tale about product identity. After a commercial dispute, the original formulation and the brand name parted company: a US court found that marketing the reformulated product as the same as the studied one was false advertising. Anyone relying on the trial evidence needs to know which physical product it attaches to, which is an unusually literal illustration of why strain identity matters.
Sold as
Sachet of powder, Capsule
Standardised to
450–900 billion CFU per sachet across eight named strains — a product without this marker may not resemble what was studied.
Also known as
VSL#3-type blend, De Simone formulation, High-potency probiotic
Regulation: Sold as a food for special medical purposes or as a dietary supplement depending on the market, with no pre-market efficacy review in the US. Litigation in the US concluded that claims equating the reformulated branded product with the original studied formulation were false, and the original formulation is now sold under a different name. Use in pouchitis and ulcerative colitis is a clinical decision, not a self-care one.
What the research used
The amounts, forms and durations published trials of High-count multi-strain blend (De Simone formulation) actually administered.
These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.
Studied for Maintenance of remission in pouchitis
900–1800 billion CFU
Moderate
Sachet, daily · 9–12 months
From small randomised trials in specialist centres following ileal pouch-anal anastomosis. The doses are far above anything in a retail probiotic and the population is specific.
Studied for Mild to moderate ulcerative colitis, as an adjunct
3600 billion CFU
Moderate
Divided daily doses alongside standard therapy · 8–12 weeks
Trials added it to mesalazine or similar treatment. It was never tested as a replacement for medical therapy.
This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.
When it was taken
Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.
None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.
🔀Split through the day
Not enough
Trial protocols divided the daily dose, largely to manage the volume of powder and the gas it produces. No comparison of dosing schedules has been published.
Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.
The evidence in depth
Best supported: Moderate
What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.
Randomised trials support this formulation for maintaining remission in pouchitis and as an add-on in mild to moderate ulcerative colitis, and it appears in some clinical guidance for those indications. The trials are small and from a limited number of centres, and the result does not extend to irritable bowel syndrome or general digestive complaints.
Moderate evidence. Several human studies point the same way, with real caveats.
Trials in inflammatory bowel disease report changes in mucosal cytokine profiles alongside clinical remission. The marker data are secondary to the clinical outcomes and come from the same small studies.
Limited evidence. Early human work, or mostly lab and animal research.
Randomised controlled trial · Liver international : official journal of the International Association for the Study of the Liver · 2013 · PMID 23968203
Randomised controlled trial · Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association · 2015 · PMID 25460016
Deep research mode adds each paper’s own conclusion and stated limitations.
Things to know
Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.
Avoid
Immunocompromise, central lines and critical illness
High-count preparations concentrate the general probiotic risk. People with inflammatory bowel disease are frequently on immunosuppressive therapy, which makes this a decision for the treating gastroenterologist rather than a self-directed purchase.
Worth knowing
Product identity changed after litigation
The formulation studied in the pouchitis and colitis trials is no longer sold under the brand name that carried it, and a US court found claims of equivalence between the old and new products to be false advertising. Anyone buying on the strength of the published trials needs to identify the correct product.
Worth knowing
Not a replacement for medical therapy
Every trial added this preparation to standard treatment. Substituting it for mesalazine, steroids or biologic therapy in inflammatory bowel disease is dangerous and was never tested.
Too much
Bloating at high doses
Substantial gas and bloating are common at these counts, particularly in the first fortnight, and are the usual reason people cannot tolerate the full dose.