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Tom’s Weight LossRankings
Dietary supplementNot tested · not scored

Metagenics UltraFlora Control

UltraFlora Control is a single-strain probiotic: Bifidobacterium lactis B420 at 113.1 mg, stated as 10 billion CFU, one capsule daily. It is the only product in this directory where the specific strain, at a comparable dose, has been through a published randomised human trial with body composition as an outcome. That is a genuinely different standard of evidence from the rest of this category — which is not the same as saying it will work for you.

Last reviewed · researched from the manufacturer’s published pages by Tom

What’s in it

Amounts are shown only where the manufacturer publishes them. Anything without a figure is undisclosed — and for an active ingredient, an undisclosed dose is the central problem with this category.

  • Bifidobacterium lactis B420113.1 mg (10 billion CFU)

    A single, named, numbered strain — not a blend

  • Microcrystalline cellulose, magnesium stearate, silicaamount not published

    Within the probiotic blend, as published

  • Hydroxypropylmethylcelluloseamount not published

    Capsule shell — vegetarian

How the manufacturer says it works

Metagenics positions it as a clinically studied probiotic for long-term weight maintenance, and states that in a six-month clinical study of overweight individuals, those taking B. lactis B420 showed reduced body fat mass, body weight and waist circumference, and a reduction in calorie intake of around 300 kcal compared with placebo. It also states that B420 consumption increases Akkermansia muciniphila in the gut.

What the evidence actually supports

This is the strongest ingredient-to-product match in the directory. B. lactis B420 has been through peer-reviewed randomised controlled research in overweight adults with body composition measured as an outcome — most probiotics sold for weight have nothing of the kind, and rely on general microbiome reasoning instead. Metagenics publishes the full Supplement Facts panel including the other ingredients, names the exact strain rather than just the species, gives both the milligram weight and the CFU count, states third-party testing, and offers a satisfaction guarantee. On disclosure, it is close to best-in-class here.

Where that evidence stops

Read the effect size, not the word 'clinical'. Reductions reported in this literature are small — a modest change in body fat over six months, not a transformation, and the comparison is against placebo in a controlled study rather than a promise about you. A single manufacturer-cited trial is evidence, not proof, and 'clinically proven' overstates what one study can establish. The claim that B420 raises Akkermansia is a mechanistic step, not an outcome. And this remains a probiotic: it is not comparable to a GLP-1 medication and Metagenics does not suggest it is.

Strengths and problems

Strengths

  • The exact named strain — B. lactis B420 — has published randomised human research with body composition measured
  • Single strain rather than a blend, so you know precisely what you are taking
  • Publishes both milligram weight (113.1 mg) and CFU count (10 billion), which almost nothing else here does
  • Full Supplement Facts and other-ingredients list published on the page
  • States third-party testing
  • Publishes a satisfaction guarantee
  • One capsule daily with clear directions

Problems

  • 'Clinically proven' overstates what a single manufacturer-cited trial can establish
  • Effect sizes in this research are small — expect a modest change, not a transformation
  • The Akkermansia claim is a mechanism, not an outcome
  • Pricing was not published on the page we captured, which is a real gap
  • Warnings and shipping terms were not published

What the manufacturer publishes

Publishes 8 of 8 standard terms.

Intended use
Sold as a dietary supplement, not as a treatment for any condition.
Directions
One capsule daily, or as directed by a healthcare practitioner, as part of a healthy diet and exercise regimen.
Warnings
Not published on the page we captured.
Allergens
Not published on the page we captured, though the full other-ingredients list is.
Third-party testing
States science-backed and third-party tested, with clinically studied ingredients for quality, purity and efficacy.
Pricing
Pricing was not clearly published on the page we captured.
Subscription
Not stated on the page we captured.
Refunds
Publishes a satisfaction guarantee and invites you to try it risk-free.
Shipping
Not stated on the page we captured.

May suit

Someone who wants the probiotic with the closest match between what was studied and what is in the bottle, and who has calibrated expectations about the size of the effect.

Do not use if

  • You are immunocompromised, critically ill, or have a central venous catheter
  • You are pregnant or breastfeeding without checking with a clinician
  • You are expecting results comparable to a prescription GLP-1 medication

Frequently asked

Is this actually different from other probiotics here?

Yes, on evidence. Most probiotics sold for weight rely on general microbiome reasoning; the specific strain in this one has been through published randomised research in overweight adults with body composition measured. That is a real distinction. It does not mean the effect is large — it means the question was actually asked.

What does the strain number mean?

Probiotic effects are strain-specific, not species-specific. 'Bifidobacterium lactis' tells you very little; 'B. lactis B420' identifies the exact organism that was studied. A product naming only the species is not selling you the studied strain.

Sources

Captured . Manufacturer pages change — check the current version before relying on anything.