Akkermansia muciniphila
Summary
Akkermansia muciniphila is a gut bacterium sold live or pasteurized. A 2019 pilot found pasteurized cells improved insulin sensitivity, but a larger 142-person trial missed its insulin-sensitivity endpoint; a 2026 trial reported less weight regain after dieting (grade C). Benefits appeared mainly in people with low baseline Akkermansia. EFSA judged pasteurized cells safe up to 3.4 × 10^10 cells/day.
Key facts
- A non-toxin-producing, avirulent bacterium reported as part of normal gut microbiota; products use live or pasteurized (inactivated) cells[6][1]
- +28.6% versus placebo with pasteurized cells in a 32-person pilot; no difference on the primary endpoint in a 142-person trial[1][2]
- 1.2 kg regain versus 3.2 kg on placebo over 24 weeks after a low-energy diet (n = 90)[4]
- Pasteurized A. muciniphila safe at 3.4 × 10^10 cells/day for adults; safety in pregnancy and breastfeeding not established[6][7]
- 5 graded human outcomes on this page
- October 13, 2026
How it works
ProposedLower Akkermansia abundance has been correlated with overweight, obesity, untreated type 2 diabetes and hypertension. Pasteurized MucT improved gut barrier function in preclinical models. In the 2019 human pilot, liver and inflammation markers fell while the overall microbiome was unchanged; how the bacterium acts in people is not established.[1][2]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Insulin sensitivity | Grade C | Mixed | RCT · n = 142 · 2026 | 2 rows |
| Weight | Grade C | Improved | RCT · n = 90 · 2026 | 1 row |
| Blood sugar | Grade D | Improved | RCT · n = 76 · 2020 | 2 rows |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Whole-body insulin sensitivity in metabolic syndrome | Mixed | Grade C | RCT · n = 142 · 2026 Adults with metabolic syndrome, with or without prediabetes (Ireland and Germany) Form: Pasteurized A. muciniphila MucT · Dose: 30 billion cells/day · Duration: 4 months The primary endpoint (Matsuda index) did not differ from placebo. Exploratory analyses found improvements in prediabetic, older and low-baseline-Akkermansia subgroups, including GLP-1 response. | 42343233 (opens PubMed)Source [2] |
| Weight regain after a low-energy diet | Improved | Grade C | RCT · n = 90 · 2026 Adults with overweight or obesity who lost at least 8% of body weight on an 8-week low-energy diet Form: Pasteurized A. muciniphila MucT · Dose: Daily (amount not stated in the abstract) · Duration: 24 weeks Weight regain was 1.2 kg versus 3.2 kg on placebo (P = 0.012), and net loss from baseline was 3.1 kg greater. No serious treatment-related adverse events. | 42120725 (opens PubMed)Source [4] |
| Post-meal glucose in type 2 diabetes (multi-strain product with Akkermansia) | Improved | Grade D | RCT · n = 76 · 2020 Adults with type 2 diabetes Form: WBF-011: inulin plus A. muciniphila, Clostridium beijerinckii, Clostridium butyricum, Bifidobacterium infantis and Anaerobutyricum hallii · Dose: Twice daily (counts not stated in the abstract) · Duration: 12 weeks Glucose area under the curve fell by 36.1 mg/dL/180 min versus placebo (P = 0.05), and HbA1c by 0.6 points; no safety or tolerability issues. | 32675291 (opens PubMed)Source [5] |
| Weight and HbA1c in type 2 diabetes with overweight | No effect | Grade D | RCT · n = 58 · 2025 Adults with type 2 diabetes and overweight or obesity Form: Live A. muciniphila strain AKK-WST01 · Dose: Not stated in the abstract · Duration: 12 weeks Weight and HbA1c fell in both groups with no between-group difference; in people with low baseline Akkermansia, the strain colonized well and lowered weight, fat mass and HbA1c. | 39879980 (opens PubMed)Source [3] |
| Insulin sensitivity, insulin and cholesterol in overweight insulin resistance | Improved | Grade D | Pilot RCT · n = 32 · 2019 Adults with overweight or obesity and insulin resistance Form: Live or pasteurized A. muciniphila · Dose: 10^10 bacteria/day · Duration: 3 months Pasteurized cells improved insulin sensitivity (+28.6%) and lowered insulin (−34%) and total cholesterol (−8.7%) versus placebo; weight fell 2.3 kg (P = 0.09). Both forms were safe and well tolerated. | 31263284 (opens PubMed)Source [1] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Pasteurized (heat-inactivated) A. muciniphila | Varies[6] | Not absorbed; acts in the gut. The EU-assessed product must have no detectable viable cells (<10 CFU/g).[6] | Safe and well tolerated at 10^10 cells/day for 3 months; no serious treatment-related adverse events over 24 weeks in the 2026 weight trial.[1][4] | Insulin sensitivity and weight maintenance |
| Live A. muciniphila | Varies[1][3] | Colonization was efficient in people with low baseline Akkermansia and poor in those with high levels.[3] | Safe and well tolerated at 10^10 cells/day for 3 months in the 2019 pilot.[1] | Insulin resistance and type 2 diabetes |
Studied doses
Doses studied in human trials ranged from 10^10 to 3 × 10^10 cells/day for 3 to 4 months, plus a 24-week weight-maintenance trial whose abstract does not state the cell count.[1][2][4]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- Pregnancy and breastfeeding
- EFSA concluded in 2025 that safety of pasteurized A. muciniphila in pregnant and breastfeeding women has not been established.[7]
- Children and adolescents
- EFSA set lower safe intakes for adolescents (2.1 × 10^10 cells/day at 12–13 years; 3.0 × 10^10 at 14–17); no assessment covers younger children.[7]
- Live products
- The EU safety opinion covers pasteurized cells with no detectable viable bacteria; it does not assess live-cell products.[6]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
- Live or pasteurizedThe best-studied product is pasteurized; the 2019 pilot reported its insulin-sensitivity improvement for the pasteurized form.[1]
- Count cells, not milligramsTrials dosed 10^10 to 3 × 10^10 cells/day; EFSA's adult safe level is 3.4 × 10^10 cells/day.[1][2][6]
- Single strain vs blendSome products mix Akkermansia with other bacteria and inulin; results from blends do not describe Akkermansia alone.[5]
Frequently asked questions
What is Akkermansia muciniphila?
A bacterium reported as part of normal human gut microbiota. Supplements contain live or pasteurized cells.[6][1]
Does Akkermansia help weight loss?
In a 2026 trial of 90 adults, pasteurized cells reduced weight regain after dieting (1.2 vs 3.2 kg). Weight changes in earlier trials were small or not significant.[4][1]
Does Akkermansia improve insulin sensitivity?
A 32-person pilot said yes for the pasteurized form, but a 142-person trial found no difference on its primary measure.[1][2]
Why is pasteurized Akkermansia used?
In the 2019 pilot, the insulin-sensitivity and cholesterol improvements were reported for pasteurized cells, and the EU safety opinion covers pasteurized cells.[1][6]
Sources
- [1]Supplementation with Akkermansia muciniphila in overweight and obese human volunteers: a proof-of-concept exploratory study.. Nat Med, 2019. RCT
- [2]Effect of pasteurized Akkermansia muciniphila MucT on insulin sensitivity, body composition, and GLP-1 production in subjects with metabolic syndrome: impact of low baseline gut Akkermansia levels.. Gut Microbes, 2026. RCT
- [3]Akkermansia muciniphila supplementation in patients with overweight/obese type 2 diabetes: Efficacy depends on its baseline levels in the gut.. Cell Metab, 2025. RCT
- [4]Pasteurized Akkermansia muciniphila Muc(T) for weight loss maintenance in people with overweight and obesity: a controlled randomized trial.. Nat Med, 2026. RCT
- [5]Improvements to postprandial glucose control in subjects with type 2 diabetes: a multicenter, double blind, randomized placebo-controlled trial of a novel probiotic formulation.. BMJ Open Diabetes Res Care, 2020. RCT
- [6]Safety of pasteurised Akkermansia muciniphila as a novel food pursuant to Regulation (EU) 2015/2283.. EFSA J, 2021. guideline
- [7]Safety of an extension of use of pasteurised Akkermansia muciniphila as a novel food pursuant to Regulation (EU) 2015/2283.. EFSA J, 2025. guideline
What changed
- Independent review: 2019 pilot (32 completers across three arms) regraded C to D, a single small trial under the grading rubric. All PMIDs re-checked.
- Strict second-pass self-review (no separate reviewer could be dispatched for this batch): all 7 PMIDs re-verified by NCBI esummary (titles and years match the record) and efetch checked for retraction, expression-of-concern and erratum flags (none flagged); every evidence row, key fact, form, dose, label line, FAQ and insight re-read against its abstract, and against PMC full text where the dose or count lives. Fixes: removed mucus-layer and mouse-study statements not supported by the cited sources, unverified countries, and a live-versus-pasteurized comparison the abstract does not make. Page set indexable.
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year from the record) and abstracts read for each cited row, including the 2021 and 2025 EFSA novel-food opinions. No NIH ODS or NCCIH fact sheet covers Akkermansia.