Akkermansia muciniphila

What it is

Akkermansia muciniphila was isolated from a stool sample at Wageningen University in 2004. Muriel Derrien described it in the laboratory of Willem de Vos. The group had been looking for bacteria that eat mucin — the mucus that lines the intestinal wall. It found one that needs nothing else and that was so distinctive that a new genus was created for it.

In healthy adults, Akkermansia often makes up a few percent of all gut bacteria. It does not sit in the intestinal contents but in the mucus layer itself — and lives off precisely the material that protects against these intestinal contents.

Why a mucus eater is supposed to strengthen the barrier

That sounds destructive, and in the animal model it is the opposite. By breaking down the old mucus, Akkermansia keeps the cells of the intestinal wall working, which continuously produce new mucus — the protective layer stays fresh and thick, like a lawn that grows better when you mow it.

The rest of the story hangs on this idea: a tight barrier, fewer bacterial components in the blood, less silent inflammation, better sugar metabolism. The full chain has only been measured in mice.

The observation that started it all

Lean, metabolically healthy people have a lot of Akkermansia in the gut. In overweight, type 2 diabetes and hypertension, there is regularly less. This inverse relationship is well documented and recurs study after study.

But it only says that the two occur together, not what causes what. That is why research moved to the animal model: in 2013 the laboratory of Patrice Cani in Louvain published a paper in PNAS in which obese mice received Akkermansia — less fat mass, less inflammation, lower insulin resistance, a tighter gut barrier.

The contradiction between live and dead

In the 2013 mouse study, only live bacteria worked; killed ones did nothing. In humans this was reversed: in 2019 the pasteurized variant, that is, killed by heating, performed best, while the live one did not show the effect cleanly.

Why this is so, no one knows. It is suspected that heating flips a protein of the bacterial envelope into a more effective form. That is a hypothesis, not proof.

Who conducted the studies

Patrice Cani and Willem de Vos, the key researchers, are co-founders of A-Mansia Biotech, which sells the product as The Akkermansia Company. The conflict of interest is stated openly in the study — it still has to be kept in mind. At the US supplier Pendulum, all study authors were employees and shareholders of the manufacturer.

What raises your own levels

The strongest indication concerns metformin: people who take the diabetes medicine have, on average, more Akkermansia in the gut. This was shown in 2017 by a Colombian study — a cross-sectional study, that is, a single snapshot, not randomized.

After that it gets softer. For cranberry the effect exists only in animals; for pomegranate there is a small human study in which the Akkermansia count rose — the same ellagitannins from which urolithin A is formed in the gut. The most reliable lever is mundane: plenty of plant fibres, which feed not only Akkermansia but the entire gut.

What the studies show

Depommier 2019, Nature Medicine — the only study on the bacterium itself

Randomized, double-blind, placebo-controlled, from the laboratory of Patrice Cani. 40 people with overweight and insulin resistance were enrolled, and 32 completed the 3 months, divided into 3 arms: live Akkermansia, pasteurized, placebo. Under the pasteurized form, insulin sensitivity rose by almost 29 percent, insulin level fell by about a third, and total cholesterol by just under 9 percent. Weight fell by just over 2 kilograms but narrowly missed the significance threshold. The authors themselves call the work a feasibility study.

Cani lab 2013, PNAS — the animal model

Obese mice received Akkermansia. Fat mass, inflammation markers and insulin resistance declined, and the gut barrier became tighter. Crucially: here only live bacteria worked — in humans, the opposite emerged in 2019.

Perraudeau 2020 — the five-strain product

What was studied was not Akkermansia alone but Glucose Control from the company Pendulum, a mixture of 5 bacterial strains with fibre: 76 people with type 2 diabetes, 12 weeks; the long-term blood sugar value fell by 0.6 points. The contribution of Akkermansia alone cannot be read from a mixture, the main value lay exactly on the significance threshold at p equal to 0.05, and all authors were employees and shareholders of the manufacturer.

Colombian cross-sectional study 2017 — metformin

People on metformin had, on average, more Akkermansia in the gut than others. The design is cross-sectional: measured once, no allocation, no time axis. It is the strongest indication of how levels can be raised from outside — and remains an observation.

Where the data stop

In humans there is exactly one study on the bacterium itself, and it is tiny: 32 evaluable participants over 3 months. In it, of all things, what sells the products is not established. The loss of just over 2 kilograms of weight missed the comparison against placebo; fat mass and hip circumference fell only against each participant’s own baseline. The contradiction between animal and human also remains open: there only live works, here only dead, and the explanation is so far a supposition about an envelope protein.

The second gap is one of time. Longevity promises a statement spanning decades; what has been measured is 3 months. No one has ever studied whether Akkermansia changes a person’s lifespan or what daily intake over years does to the mucus layer. And whether little Akkermansia contributes to overweight or the other way round cannot be decided from observational data.

Status, approval and legal

In 2021 the European authority EFSA assessed exactly one form: pasteurized, killed Akkermansia muciniphila as a novel food. The EU regulation followed in early 2022. It stipulates that practically no live cells may remain, caps the amount at a maximum of 5 times 10 to the power of 10 cells per day, and excludes pregnant and breastfeeding women. Live Akkermansia is not authorized as a food in the EU — anyone offered it here is buying something without authorization status; in the US the live product goes through a different regulatory route. There is no medicinal product approval anywhere, and it has no doping relevance.

Safety

In the studies, Akkermansia was remarkably well tolerated: the pasteurized form was tolerated over 3 months without notable side effects. The limit lies in the scope: months in a few dozen people, not years in thousands. What long-term intake does to the mucus layer and the microbiome has not been studied. The EU authorization excludes pregnant and breastfeeding women. Anyone taking immunosuppressants or with a serious bowel disease is better off clarifying bacterial preparations with a physician.

Sources

• Derrien et al., International Journal of Systematic and Evolutionary Microbiology 2004 — first description of Akkermansia muciniphila, Wageningen University
• Everard et al. (Cani lab), PNAS 2013 — Akkermansia in obese mice
• Depommier et al., Nature Medicine 2019 — randomized, double-blind feasibility study in humans
• Perraudeau et al., BMJ Open Diabetes Research & Care 2020 — five-strain probiotic in type 2 diabetes
• de la Cuesta-Zuluaga et al., Diabetes Care 2017 — Colombian cross-sectional study on metformin and Akkermansia abundance
• EFSA, 2021 — assessment of pasteurized Akkermansia muciniphila as a novel food
• Commission Implementing Regulation (EU) 2022/168 of February 8, 2022 — authorization of the pasteurized form as a novel food