The pasteurised paradox: why dead bacteria worked better than live ones

There is a detail about Akkermansia muciniphila that surprises almost everyone the first time they hear it: in the research, the pasteurised form — heat-treated, non-living bacteria — worked better than the live form. For a category built on the idea of "live cultures," that is genuinely counterintuitive. Here is what happened.

The clue from the lab

In 2017, Hubert Plovier and colleagues set out to understand how Akkermansia improves metabolism. Working in obese and diabetic mice, they made a striking discovery: a single protein from the bacterium's outer membrane — later studied as Amuc_1100 — reproduced much of the metabolic benefit on its own. And crucially, the pasteurised bacterium worked at least as well as the live one (Plovier et al., 2017).

Why would heat-killing help? Because if the active component is a structural protein on the cell surface, you do not need the bacterium alive. Pasteurisation stops the cells from being viable but preserves those surface proteins. You keep the part that matters and lose the unpredictability of a living organism.

The first human trial

Two years later, that idea was tested in people. Clara Depommier and colleagues ran the first human study of Akkermansia supplementation: 32 overweight, insulin-resistant adults took live Akkermansia, pasteurised Akkermansia, or a placebo every day for three months (Depommier et al., 2019).

The primary goal was simply safety — and on that, both forms passed: well-tolerated, no significant adverse effects. But the metabolic markers told the more interesting story. The group taking the pasteurised form showed the clearest improvements, including in insulin sensitivity and several markers of metabolic health, while the live form did not separate from placebo as cleanly.

The lab prediction held up in humans: the pasteurised form was, if anything, the more useful one.

Why this matters for regulation — and for you

This is not a minor scientific footnote. It is the foundation of how Akkermansia is sold legally in Europe. In 2022, the European Union authorised pasteurised Akkermansia muciniphila as a Novel Food — the heat-treated, non-living form, the same one studied by Depommier and colleagues. The live form does not have that authorisation as a food supplement.

So when Vekovia uses pasteurised Akkermansia, it is not a compromise or a shelf-life shortcut. It is the form with the human evidence behind it and the regulatory approval to match.

Where the science is now

The 2019 trial was small and exploratory — its authors said so plainly. But the work has continued. In 2025, a larger trial published in Cell Metabolism extended the research into people with type 2 diabetes (Zhang et al., 2025), part of a steadily growing human evidence base.

We will keep saying it because it is true: this is early science, and we describe it rather than promise outcomes from it. But the pasteurised paradox is one of the most elegant findings in the field — and the reason the bottle in your hand contains the form that was actually studied.