Fermented Meat and Gut Health: Lessons from a Greenland Expedition

Can a diet consisting almost entirely of decomposing meat actually be healthy? While modern nutritional guidelines typically emphasize plant-based foods and warn against uncooked meats, the traditional Inuit diet tells a different story. To understand the intersection of ancient food practices and modern biology, British explorer and chef Mike Keen is undertaking a grueling journey across the icy north of Greenland, subsisting entirely on fermented seal meat.

This expedition isn’t just a feat of endurance; it’s a scientific case study. By collaborating with microbiologists, Keen aims to uncover how the human gut microbiome adapts to a diet that contradicts almost every Western health norm.

The Greenland Experiment: A Proxy for Ancient Survival

Keen is skiing roughly 320 kilometers across northern Greenland accompanied by a sled dog. To simulate how past Inuit and other Arctic peoples survived barren landscapes, the duo is eating nothing but slowly decomposing seal meat.

The journey serves a dual purpose. For Keen, it is a culinary experiment to explore the boundary between fermentation and rot. For science, it is a data-collection mission. Throughout the trek, Keen is collecting fecal samples from himself and his dog, which are then analyzed by Aviâja Lyberth Hauptmann, an Inuit microbiologist at the University of Greenland in Nuuk.

The goal is to observe how the gut microbiome—the community of trillions of microbes living in the intestines—shifts when moving from a Western diet to a traditional Inuit diet.

Fermentation vs. Rotting: Understanding the Difference

To the average consumer, the idea of eating “decomposing” meat sounds dangerous. However, there is a critical biological distinction between food that is rotting and food that is fermenting.

• Fermentation: A process where microbes break down food in a gradual, controlled manner. This process can free up nutrients, making them easier for the body to digest.
• Rotting: Uncontrolled microbial growth that renders food dangerous to eat due to the proliferation of pathogens.

In Inuit culture, these fermented meats are collectively known as igunaq, which can include walrus, caribou, reindeer, and seal. One specific delicacy, kiviak, involves stuffing small birds inside seal hides and burying them under rocks for several months.

Archaeologist John Speth, writing in PaleoAnthropology in 2022, noted that humans have long eaten fermented meats “to the edge of safety.” While modern observers might expect frequent outbreaks of foodborne illness, Speth found few historical references to botulism in indigenous practices, suggesting that these methods were finely tuned over millennia to protect the community.

The Impact on the Gut Microbiome

Western diets are characterized by processed foods and a variety of fruits and vegetables. In contrast, the traditional Inuit diet is approximately 98 percent meat. While high-meat diets in the West are often linked to heart disease and digestive disorders, Inuit populations historically maintained their health without these issues before the introduction of Danish food imports.

Hauptmann hypothesizes that the practice of fermenting meat for months enhances microbial diversity, which in turn supports gut health. “There is a way to live healthily off an animal-sourced diet,” Hauptmann states. “We are missing an understanding of what that looks like.”

Evidence from Keen’s previous expedition—a kayaking trip documented in the film Qajaq Man—already shows a dramatic biological shift. Hauptmann’s forthcoming research in Frontiers in Microbiomes indicates that microbes adapted to eating plants and fibers disappeared from Keen’s gut, replaced by strains better suited for high-fat, high-protein diets.

The Risks of Losing Traditional Knowledge

Despite the benefits of traditional fermentation, there are significant risks if the process is done incorrectly. The primary danger is botulism, a severe form of food poisoning.

Speth notes that cases of botulism began appearing in Alaskan health records several decades ago. This trend coincided with a shift in practice: moving from fermenting meats below ground to using above-ground containers. To mitigate this risk during his current trek, Keen wraps seal meat in skins and keeps the bundles on an insulated blanket to maintain a temperature just above freezing, preventing the meat from fermenting too quickly.

Scientific Perspectives and Genetic Adaptations

Not all experts agree on the value of a single-person case study. Patrick Mullie, a nutritionist and epidemiologist with the Belgian Defence, suggests that studying the microbiomes of native Greenlanders would provide more meaningful data than focusing on “an Englishman and a dog.”

However, studying an outsider allows researchers to see rapid microbial adaptation in real-time. Native populations have had generations to evolve; for example, a 2015 study in Science reported that Greenland Inuit have specific genetic adaptations that help them process a fat-heavy diet. Because genetic change is leisurely, researchers believe microbes play the primary role in helping humans adapt quickly to new environments or diets.

As global diets become more homogenized and reliant on imported processed foods, the study of traditional diets like that of the Inuit offers a glimpse into alternative ways of maintaining human health. As Hauptmann emphasizes, understanding these practices is not just about science, but about the right of indigenous people to maintain their own dietary traditions.