Akkermansia muciniphila and Metabolic Health

Akkermansia muciniphila has moved from laboratory curiosity to one of the most talked-about gut bacteria in British health shops in under a decade — and three human randomised trials have now reported measurable effects.

Wider context sits in our longevity supplements guide and the anti aging supplements range. For this category specifically, see the gut health supplements and probiotics collections, and our own Akkermansia supplement.

This guide explains what A. muciniphila does, what the human evidence genuinely shows and where it falls short, the specific regulatory position in Great Britain, and how to evaluate a product.

What is Akkermansia muciniphila?

Akkermansia muciniphila is a Gram-negative, oval-shaped, strictly anaerobic bacterium first isolated from a human stool sample in 2004. It belongs to the phylum Verrucomicrobia and is, unusually, the only member of that phylum commonly cultivated from the human gut [5].

Its name is the clue: muciniphila means "mucin-loving". Rather than fermenting dietary fibre, it feeds on mucin — the heavily glycosylated protein making up the protective mucus layer lining your intestine.

Where it lives in the gut

Most gut bacteria live in the lumen, the open channel where digested food passes. A. muciniphila is different: it colonises the outer mucus layer of the colon, sitting far closer to your intestinal epithelium than most commensals [5]. That proximity is central to its biology — it is positioned to communicate directly with the cells regulating barrier integrity, immune signalling and hormone release.

Why it is called a "next-generation" beneficial microbe

Traditional probiotics — Lactobacillus and Bifidobacterium — were largely selected because they were easy to grow and had a history of safe use in fermented foods. Akkermansia was selected the other way round: researchers noticed its abundance tracked with health outcomes, then worked out how to culture it. A 2022 review in Nature Reviews Gastroenterology & Hepatology described it as the paradigm case for a new generation of beneficial microorganisms defined by mechanism rather than tradition [5].

Live bacteria vs pasteurised postbiotic

This is the single most counter-intuitive fact about Akkermansia, and it matters when shopping. In 2017, Plovier and colleagues reported in Nature Medicine that pasteurising the bacterium did not destroy its metabolic benefits in mice — it enhanced them [7]. The active component appears to be a heat-stable outer membrane protein, Amuc_1100, which survives pasteurisation and signals through Toll-like receptor 2.

A heat-killed preparation is technically a postbiotic, not a probiotic. It cannot colonise, is not affected by antibiotics, does not require refrigeration, and has a far more predictable shelf life. It is also the form European and British regulators have assessed [9,10,12].

How it influences metabolic health

The proposed mechanisms are unusually well characterised for a supplement ingredient, which is a large part of why the scientific community takes it seriously.

1. Strengthening the gut barrier

It sounds paradoxical that a mucin-eating bacterium would improve the mucus layer, but the relationship is stimulation rather than depletion. By continuously grazing the outer mucus, A. muciniphila prompts goblet cells to produce more mucin, increasing turnover and thickness. In the landmark 2013 PNAS study, administering A. muciniphila to obese mice restored mucus thickness and reversed several features of diet-induced metabolic disease [6]. Later mouse work found the pasteurised form also increased whole-body energy expenditure and faecal energy excretion [2].

2. Reducing metabolic endotoxaemia

A thin or leaky intestinal barrier allows lipopolysaccharide to cross into circulation. Even modest chronic elevations drive low-grade systemic inflammation — metabolic endotoxaemia — strongly implicated in insulin resistance and fatty liver [5,6]. Chronic inflammation of this kind is one of the recognised hallmarks of ageing, which is why gut barrier integrity became a longevity topic and not just a digestive one.

3. Short-chain fatty acid production

A. muciniphila ferments mucin into acetate and propionate. These short-chain fatty acids feed other beneficial species — notably butyrate producers, via cross-feeding — and act as signalling molecules affecting appetite, glucose handling and colonocyte energy supply [5]. See butyrate supplements in the UK and sodium butyrate vs tributyrin.

4. GLP-1 and appetite signalling

Enteroendocrine L-cells release glucagon-like peptide-1, the hormone targeted by semaglutide and similar medications. Research has identified an Akkermansia-derived protein that can stimulate GLP-1 secretion [5].

5. Amuc_1100 and immune signalling

The outer membrane protein Amuc_1100 interacts with Toll-like receptor 2, improving tight junction expression and modulating inflammatory cytokine production [7]. Because Amuc_1100 is heat-stable, this mechanism is preserved — possibly made more available — in pasteurised preparations.

What the human evidence actually shows

Mouse data is extensive and consistently positive. Human data is much thinner but has grown since 2019. Here is what exists.

The 2019 proof-of-concept study

Depommier and colleagues ran a randomised, double-blind, placebo-controlled pilot in Belgium. Forty overweight or obese, insulin-resistant volunteers were enrolled; 32 completed three months of daily supplementation with live A. muciniphila, pasteurised A. muciniphila, or placebo [1].

Published in Nature Medicine: compared with placebo, pasteurised A. muciniphila improved insulin sensitivity by 28.6%, reduced fasting insulin by 34.1% and lowered total cholesterol by 8.7%. Body weight fell slightly (−2.27 kg) but this did not reach statistical significance. Markers of liver dysfunction and inflammation improved, and the intervention was safe and well tolerated [1].

The caveats matter equally: an exploratory study with roughly a dozen participants per arm, primarily designed to assess safety and feasibility rather than prove efficacy. It was never intended to be definitive [1].

The 2025 type 2 diabetes trial

Zhang and colleagues published a 12-week, randomised, double-blind, placebo-controlled multicentre trial in Cell Metabolism, involving 58 participants with overweight or obesity and type 2 diabetes, using a live strain designated AKK-WST01 [3].

The finding that reshaped the field: the strain only worked in people who started with low Akkermansia levels. In those participants it colonised effectively and produced significant reductions in body weight, fat mass and HbA1c. In participants with high baseline abundance it colonised poorly and produced no significant clinical improvement. The authors framed this as a case for microbiota-guided, personalised supplementation [3].

The 2026 weight-loss maintenance trial

The largest and most rigorous trial to date was published in Nature Medicine in May 2026 by Mount, Canfora, Blaak and colleagues at Maastricht University. Ninety adults with overweight or obesity completed an 8-week low-energy diet to achieve at least 8% weight loss, then spent 24 weeks on an ad libitum healthy diet with daily pasteurised A. muciniphila MucT or placebo [4].

The supplemented group regained 1.2 ± 0.7 kg versus 3.2 ± 0.4 kg in placebo (P = 0.012), and ended with greater net weight loss from baseline — a difference of 3.1 ± 0.7 kg (P = 0.009). Baseline Akkermansia abundance again predicted cardiometabolic response. No serious treatment-related adverse events occurred [4].

Summary of human trial evidence

What the evidence does not show

To be clear about the limits: there is no evidence that Akkermansia treats or cures type 2 diabetes, obesity, fatty liver disease or any other condition. There are no long-term outcome trials measuring heart attacks, strokes or mortality. Total participant numbers across all human trials remain under 200. Effect sizes are real but modest, and appear to depend on who you are before you start [3,4]. Anyone marketing Akkermansia as a weight-loss drug substitute is well ahead of the data.

Akkermansia UK: legal and regulatory status

This is where UK buyers need to pay attention, because the position in Great Britain differs from both the EU and the US — and it directly affects which products you can trust.

Great Britain

Because Great Britain operates its own novel foods regime post-Brexit, EU authorisation does not carry across automatically. An application was submitted to the Food Standards Agency in February 2022 by The Akkermansia Company SA. The Advisory Committee on Novel Foods and Processes reviewed it across meetings in 2023 and 2024, and the FSA and Food Standards Scotland finalised their safety assessment on 17 September 2024 [12].

Their conclusion: pasteurised A. muciniphila is safe for the general population aged 12 and over at up to 4 × 10¹⁰ cells per day in food supplements and foods for special medical purposes [12,13]. Because regulatory status can change, check the FSA's public register before purchasing.

European Union

Following a 2021 EFSA opinion, pasteurised A. muciniphila (strain ATCC BAA-835, also CIP 107961, referred to in the literature as MucT) was authorised by Commission Implementing Regulation (EU) 2022/168 in February 2022 — for adults, excluding pregnant and breastfeeding women, at a maximum of 3.4 × 10¹⁰ cells per day [10,14].

EFSA then assessed an extension of use, concluding in 2025 that the novel food is safe at up to 2.1 × 10¹⁰ cells/day for adolescents aged 12 to under 14, and 3.0 × 10¹⁰ cells/day for those aged 14 to under 18 [11]. The European Commission adopted that extension on 23 February 2026 via Regulation (EU) 2026/391, widening the permitted population to ages 12 and over with age-differentiated maximum intakes [14].

Live Akkermansia products sold in the UK

You will find live Akkermansia products on UK marketplaces, often imported and sometimes shipped from outside the UK. The GB novel foods assessment covered the pasteurised form specifically [12]. Live preparations occupy a murkier position, and products arriving via third-party marketplace sellers may not have been assessed under GB rules at all. Favour suppliers who state the form clearly, name the strain, and can point to the relevant regulatory pathway. See third-party tested supplements and reading a certificate of analysis.

A note on Qualified Presumption of Safety

For balance: the EFSA Panel on Biological Hazards reviewed A. muciniphila for Qualified Presumption of Safety status in 2020 and again in 2024, and on both occasions declined to grant it [11]. The species-level picture is not settled, even while specific pasteurised preparations have passed dedicated safety assessments. That distinction — species versus specific assessed preparation — is worth holding onto when reading marketing copy.

Who might consider it — and who should not

Where the rationale is strongest

• Adults with insulin resistance, central adiposity or metabolic syndrome features, working alongside — not instead of — medical care.
• People in the maintenance phase after intentional weight loss, the scenario the 2026 trial specifically tested [4].
• People with a Western dietary pattern low in fibre and polyphenols, in whom abundance is more likely depleted.
• Those who have tested and found low baseline levels, given that both the 2025 and 2026 trials found baseline abundance modified the response [3,4].

Where caution is warranted

• Pregnancy and breastfeeding. Safety has not been established. EFSA's 2025 opinion stated explicitly that no evidence was provided for safety in pregnant and lactating women [11].
• Immunosuppression or critical illness. Standard caution applies to any microbial preparation; discuss with your clinician first.
• Active inflammatory bowel disease. Evidence is mixed and mucin dynamics differ in inflamed bowel. Take clinical advice.
• Neurodegenerative disease. Some observational studies have reported increased Akkermansia abundance in people with Parkinson's disease. Causality is unknown, but it is a reason for measured expectations rather than enthusiasm.
• Anyone on prescribed medication, particularly for diabetes, given the potential for additive glucose-lowering effects.

Dosage, timing and how to take it

Typical dose

Human trials and regulatory assessments cluster around 10¹⁰ cells per day. The 2019 trial used 10¹⁰ cells daily [1]. EFSA set 3.4 × 10¹⁰ cells/day as the safe adult maximum [10]; the FSA and FSS assessed up to 4 × 10¹⁰ cells/day [12]. Most UK products land in this range, often expressed as AFU (active fluorescent units) rather than CFU, because inactivated cells cannot form colonies.

With or without food?

Pasteurised preparations do not need protection from stomach acid the way live cultures do, so timing is less critical. Many manufacturers suggest taking with food for tolerability. Live products are more often recommended on an empty stomach or with a light meal. See which supplements to take on an empty stomach and the supplement timing chart.

How long before anything happens?

Set realistic expectations. The metabolic changes reported in trials emerged over 12 weeks to 6 months, and were measured with blood tests and body composition scans rather than felt as subjective effects [1,3,4]. You should not expect to notice Akkermansia working. See how long supplements take to work.

Stacking

Generally compatible with other gut and longevity supplements, and the polyphenol and prebiotic ingredients often paired with it may support its growth. See whether you can take supplements together and how it fits into a broader longevity stack.

How to increase Akkermansia naturally

Before spending money on a supplement, several dietary and lifestyle factors have been associated with higher Akkermansia abundance.

Polyphenol-rich foods

Polyphenols from cranberries, pomegranates, grapes, green tea and cocoa have been repeatedly associated with increased abundance in animal and early human studies [5]. The proposed mechanism is that polyphenols reaching the colon selectively favour its growth while suppressing competitors. Pomegranate polyphenols are also the precursor to urolithin A — see urolithin A in the UK and our Mitopure review.

Dietary fibre and prebiotics

Although Akkermansia eats mucin rather than fibre directly, a high-fibre diet supports the whole ecosystem and the cross-feeding networks it participates in [5]. Inulin from chicory root, oligofructose and resistant starch are commonly included in Akkermansia formulations for this reason. UK adults average well below the recommended 30 g of fibre per day [17], a plausible contributor to depleted populations. Population-level dietary patterns are discussed in Blue Zones and longevity.

Caloric restriction and fasting

In the 2016 Gut study by Dao and colleagues, participants with higher baseline Akkermansia showed better metabolic improvement during a calorie-restricted dietary intervention [8]. Fasting and time-restricted eating have also been associated with increased abundance, plausibly because reduced food intake increases relative reliance on mucin as a substrate. This connects to autophagy mechanisms.

Exercise

Regular moderate aerobic exercise is associated with greater microbiome diversity and, in several studies, higher Akkermansia. See zone 2 training for longevity.

Metformin

One of the more intriguing findings in this field is that metformin consistently increases Akkermansia abundance in people who take it, and some researchers have proposed this is part of how metformin exerts its metabolic effects [5]. See berberine vs metformin and metformin for longevity. Metformin is prescription-only and is not a longevity shortcut.

How to choose a product in the UK

Check the form and the strain

A credible product will state whether it contains pasteurised or live cells and will name the strain. The strain used in the EU and GB regulatory dossiers is ATCC BAA-835 (also CIP 107961, referred to as MucT) [10,12]. Vague labelling saying only "Akkermansia muciniphila" with no strain designation is a warning sign.

Check the cell count and how it is expressed

Look for a dose around 10¹⁰ cells per daily serving. Note whether the count is expressed as cells, AFU or CFU — CFU is only meaningful for live products. "30 billion AFU" is 3 × 10¹⁰.

Check the testing

Ask whether the manufacturer will supply a batch-specific certificate of analysis confirming cell count, identity and absence of contaminants. See certificates of analysis, third-party testing and supplement fillers.

Expect to pay more than for a standard probiotic

Akkermansia is anaerobic, slow-growing and difficult to manufacture at scale, which is reflected in the price. UK products typically sit between £40 and £75 per month, considerably more than a conventional multi-strain probiotic — compare with the wider probiotics range. See why supplements are expensive and the real cost of a longevity stack in the UK.

Akkermansia vs other gut and longevity supplements

These are complementary rather than competing. Akkermansia targets the gut barrier and metabolic signalling; NAD⁺ precursors target cellular energy metabolism. If considering both, see our NMN benefits, side effects and dosage guide, the NAD supplement guide, the NMN supplements range, NMN Pro 1000 and the spermidine UK buying guide. Those tracking outcomes may also want biological age testing and glutamine vs collagen for gut health.

Side effects and safety

Across human trials, pasteurised A. muciniphila has been well tolerated with no serious treatment-related adverse events reported. The 2019 study reported no changes in safety parameters over three months [1]; the 2026 trial likewise reported none over 24 weeks [4].

Reported effects have generally been mild and gastrointestinal:

• Mild bloating or wind, particularly in the first one to two weeks
• Changes in stool consistency or frequency
• Occasional mild abdominal discomfort

Much of this may be attributable to the prebiotic fibres — typically chicory inulin and oligofructose — included in many formulations rather than to the bacterium itself. Starting on alternate days for the first week is a reasonable way to assess tolerance.

Speak to a GP or pharmacist before starting if you are pregnant or breastfeeding, are immunocompromised, have inflammatory bowel disease, take diabetes medication, or have a central venous catheter or recent gastrointestinal surgery. Anyone in Great Britain can check the FSA's regulated products register to confirm the current status of a novel food ingredient.

Frequently asked questions

Is Akkermansia legal to buy in the UK?

Pasteurised Akkermansia muciniphila completed a full safety assessment by the Food Standards Agency and Food Standards Scotland, finalised on 17 September 2024, concluding it is safe at up to 4 × 10¹⁰ cells per day for people aged 12 and over [12,13]. It has been authorised in the EU since February 2022 under Commission Implementing Regulation (EU) 2022/168, with the permitted age range extended in February 2026 [14]. Check the FSA's public register for the current position before buying.

What is the best time of day to take Akkermansia?

There is no evidence favouring a particular time. Pasteurised products are stable and not acid-sensitive, so many manufacturers simply suggest a capsule daily with a meal for tolerability. Live products are more commonly recommended on an empty stomach or with a light meal. Consistency matters far more than timing — the trials that showed benefit used uninterrupted daily dosing over three to six months [1,4].

Does Akkermansia help with weight loss?

The strongest evidence is for weight loss maintenance rather than weight loss itself. In the 2026 Nature Medicine trial, participants who had already lost at least 8% of body weight regained 1.2 kg over 24 weeks on pasteurised Akkermansia versus 3.2 kg on placebo [4]. In the 2019 trial, weight reduction did not reach statistical significance [1]. It is not a weight-loss drug and should not be compared to one.

Should I take live or pasteurised Akkermansia?

The pasteurised form has the stronger regulatory footing in the UK and EU [10,12], is more stable, and performed better than live bacteria in the 2019 head-to-head trial [1]. The active membrane protein Amuc_1100 is heat-stable, so pasteurisation does not destroy the mechanism [7]. A 2025 trial using a different live strain did show benefit in people with low baseline levels [3], so live preparations are not without evidence — but pasteurised is the better-characterised choice for most UK buyers.

How long does Akkermansia take to work?

Human trials measured outcomes at 12 weeks to 6 months [1,3,4]. You will not feel it working, because the changes measured were in insulin sensitivity, cholesterol and body composition rather than symptoms. Plan for a minimum three-month trial and, ideally, before-and-after blood tests.

Do I need to refrigerate Akkermansia supplements?

Pasteurised products contain inactivated cells and are generally shelf-stable at room temperature — one of their practical advantages. Live Akkermansia products usually require refrigeration to maintain viability, and manufacturers will state this. Always follow the storage instructions on the specific product.

Can I take Akkermansia with metformin or diabetes medication?

Speak to your GP, diabetes nurse or pharmacist first. Metformin already increases Akkermansia abundance [5], and both may have glucose-lowering effects, so combining them warrants monitoring. Anyone taking medication for blood glucose should not start a new supplement without clinical input, and should not adjust prescribed doses on their own.

How can I tell if my Akkermansia levels are low?

The only way is a stool microbiome test reporting at species level. Several consumer tests available in the UK do this, though analytical methods and reference ranges vary considerably between providers. Given that both the 2025 and 2026 trials found baseline abundance predicted response [3,4], testing first is a reasonable step if you want to spend efficiently rather than guess.

Is Akkermansia safe during pregnancy?

No. Safety has not been established in pregnancy or breastfeeding. EFSA's 2025 opinion on extending the authorised population noted specifically that no evidence was provided for safety in pregnant and lactating women [11]. Avoid it in these circumstances unless a clinician advises otherwise.

Is Akkermansia worth the money compared to eating more fibre and polyphenols?

For most people, diet should come first. A genuinely high-fibre, polyphenol-rich diet is cheaper, has far broader benefits, and is supported by evidence dwarfing anything available for Akkermansia supplements [17]. A supplement makes most sense as an addition to that foundation — particularly for people maintaining weight loss [4], or those with tested low baseline levels [3] — rather than as a substitute for it.

The bottom line

Akkermansia muciniphila is one of the better-evidenced novel gut ingredients available in the UK, with a plausible mechanism, three human randomised controlled trials, and a completed British safety assessment behind it [1,3,4,12]. That places it well ahead of most things sold in the longevity category.

It is not a metabolic cure. Total human participants across all trials remain under 200. Effects are modest, appear to depend on your starting microbiome, and have not been tested for long-term health outcomes. Treat it as a reasonable, evidence-informed addition to a diet and exercise foundation — not as a replacement for either, and certainly not as an alternative to medical treatment for a diagnosed condition.

If you are new to this area, start with how to start longevity supplements and our minimal effective supplement stack, and browse the gut health range.

References

1. Depommier C, Everard A, Druart C, et al. Supplementation with Akkermansia muciniphila in overweight and obese human volunteers: a proof-of-concept exploratory study. Nature Medicine. 2019;25(7):1096–1103. https://pmc.ncbi.nlm.nih.gov/articles/PMC6699990/
2. Depommier C, Van Hul M, Everard A, et al. Pasteurized Akkermansia muciniphila increases whole-body energy expenditure and fecal energy excretion in diet-induced obese mice. Gut Microbes. 2020;11:1231–1245. https://doi.org/10.1080/19490976.2020.1737307
3. Zhang Y, Liu R, Chen Y, et al. Akkermansia muciniphila supplementation in patients with overweight/obese type 2 diabetes: efficacy depends on its baseline levels in the gut. Cell Metabolism. 2025;37(3):592–605. https://pubmed.ncbi.nlm.nih.gov/39879980/
4. Mount S, Canfora EE, Jocken JW, et al. Pasteurized Akkermansia muciniphila MucT for weight loss maintenance in people with overweight and obesity: a controlled randomized trial. Nature Medicine. 2026. doi:10.1038/s41591-026-04394-7. https://www.nature.com/articles/s41591-026-04394-7
5. Cani PD, Depommier C, Derrien M, Everard A, de Vos WM. Akkermansia muciniphila: paradigm for next-generation beneficial microorganisms. Nature Reviews Gastroenterology & Hepatology. 2022;19:625–637. https://www.nature.com/articles/s41575-022-00631-9
6. Everard A, Belzer C, Geurts L, et al. Cross-talk between Akkermansia muciniphila and intestinal epithelium controls diet-induced obesity. PNAS. 2013;110(22):9066–9071. https://doi.org/10.1073/pnas.1219451110
7. Plovier H, Everard A, Druart C, et al. A purified membrane protein from Akkermansia muciniphila or the pasteurized bacterium improves metabolism in obese and diabetic mice. Nature Medicine. 2017;23:107–113. https://doi.org/10.1038/nm.4236
8. Dao MC, Everard A, Aron-Wisnewsky J, et al. Akkermansia muciniphila and improved metabolic health during a dietary intervention in obesity. Gut. 2016;65:426–436. https://doi.org/10.1136/gutjnl-2014-308778
9. International Scientific Association for Probiotics and Prebiotics. Pasteurized Akkermansia muciniphila as a postbiotic: EFSA approval and beyond. https://isappscience.org/pasteurized-akkermansia-muciniphila-as-a-postbiotic-efsa-approval-and-beyond/
10. EFSA Panel on Nutrition, Novel Foods and Food Allergens. Safety of pasteurised Akkermansia muciniphila as a novel food pursuant to Regulation (EU) 2015/2283. EFSA Journal. 2021;19(9):6780. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8409316/
11. EFSA Panel on Nutrition, Novel Foods and Food Allergens. Safety of an extension of use of pasteurised Akkermansia muciniphila as a novel food. EFSA Journal. 2025;23(9):e9632 — including the BIOHAZ Panel's 2020 and 2024 decisions not to grant Qualified Presumption of Safety status. https://efsa.onlinelibrary.wiley.com/doi/full/10.2903/j.efsa.2025.9632
12. Advisory Committee on Novel Foods and Processes. Committee advice on the assessment of pasteurised Akkermansia muciniphila as a novel food for use in supplements (RP1468). Assessment finalised 17 September 2024. https://acnfp.food.gov.uk/ACNFPassessmentofPasteurisedAkkermansiamuciniphila
13. Food Standards Agency & Food Standards Scotland. Safety assessment on pasteurised Akkermansia muciniphila used as a food supplement (RP1468). 2024. https://doi.org/10.46756/001c.125531
14. European Commission. Union list of novel foods — Commission Implementing Regulation (EU) 2022/168 and the extension of use adopted 23 February 2026 by Regulation (EU) 2026/391. https://food.ec.europa.eu/food-safety/novel-food/authorisations/union-list-novel-foods_en
15. ClinicalTrials.gov. Akkermansia and weight maintenance (NCT05417360). https://clinicaltrials.gov/study/NCT05417360
16. Science Media Centre. Expert reaction to an RCT on the use of pasteurized Akkermansia muciniphila MucT for weight loss maintenance after an 8-week low-energy diet. May 2026. https://www.sciencemediacentre.org/expert-reaction-to-an-rct-on-the-use-of-pasteurized-akkermansia-muciniphila-muct-for-weight-loss-maintenance-after-an-8-week-low-energy-diet/
17. NHS. How to get more fibre into your diet. https://www.nhs.uk/live-well/eat-well/digestive-health/how-to-get-more-fibre-into-your-diet/

All product photography in this article is owned by Welzo and served from the Welzo media library. Research positions correct at the time of publication.