Culture Shift - Asimov Press

[BootinUp]

We tend to think of fermented foods as something humans invented and then chose to eat. But the evidence shows the opposite: fermented foods shaped human biology.
Asimov Press
Mar 20, 2026

By Rachel Dutton

The human immune system is, in one sense, a detection mechanism. It has evolved, over millions of years, to scan the body for molecular signals that tell it whether to attack or stand down. Most of these signals come from pathogens, damaged cells, or the body’s own hormones. But in 2019, a lab in Germany published a finding that pointed to a much stranger source: one of the signals sensed by the immune system is found in sauerkraut.

When people eat sauerkraut, a molecule called phenyllactic acid (D-PLA) — found in fermented foods — enters their bloodstream and activates a receptor, known as HCA3, on immune cells, triggering an anti-inflammatory response. In addition to lactic acid, phenyllactic acid is one of many compounds produced by lactic acid bacteria during the fermentation of sauerkraut and related fermented foods. Prior to this study, other molecules had been found to bind HCA3, but D-PLA was a hundredfold more potent than any of them.

This discovery advances our understanding of how fermented foods can reduce inflammation and positively affect human health. But more striking is what it suggests about hominid physiology. Although HCA3 is part of a larger family of receptors broadly conserved across eukaryotes, HCA3 is only present in humans and other great apes like chimpanzees and gorillas — and not even in other mammals. It is a recent addition to the genome, appearing only a few million years ago. Its existence seems to suggest that our immune system evolved to recognize the microbial metabolites from fermented foods.

We tend to think of fermented foods as something humans invented and then chose to eat. But, increasingly, scientific evidence suggests the causality runs the other way. Fermented foods appear to have helped shape human biology itself, and our bodies may have been built, in part, to expect them. The case for this runs from changes in hominid gut anatomy millions of years ago to the HCA3 receptor, to a growing body of research linking fermented food consumption to immune function and gut health. And it raises an uncomfortable question about what happened when the Western food system, in the name of safety and efficiency, quietly removed these foods from our diets in the nineteenth and twentieth centuries.

Continued
https://open.substack.com/pub/cell/p/culture-shift

[MatthewStLouis]

1. I agree! I feel like I digest certain foods better after eating fermented food with live cultures.

This is anecdotal, I know, but I honestly digest peanut butter better (without stomach cramps) after I eat live sauerkraut or kimchi.

I highly recommend the lady on cleanfoodliving.net (or her youtube channel) for starting a journey of fermenting. She has an awesome recipe for sauerkraut and one for red cabbage beet kraut that is my absolute favorite. I also recommend trying fermented carrots. I actually have a carrot allergy, but can tolerate cooked carrots and have found fermented carrots to be ok as well. I believe cooking and fermenting both alter the proteins enough to make the allergenic proteins in carrots tolerable. *I cannot guarantee everyone will have this result, so please use caution if you have a more severe reaction to any allergenic foods.

[erronis]

2. That's a fascinating full article. In my fridge I have examples of lactic, butyric, and acetic foods.

The fossil record shows that a major shift in hominid anatomy occurred around 2 million years ago, when hominids developed a smaller rib cage and larger skull. At the same time, another major change took place in their intestines. Compared to our closest relatives, humans have a digestive tract that is 40 percent shorter. This decrease was thought to be driven by the external processing of our food, which reduced the time and energy involved in chewing and digesting. Anthropologist Richard Wrangham argues that the technological innovations of controlling fire and cooking food led to this major change, and that the excess energy we got from cooked food, in turn, supported the evolution of a larger brain.

However, two recent studies, by biological anthropologist Katie Amato in 2021 and evolutionary biologist Erin Hecht in 2023, suggest that these anatomical changes may have been driven by human use of fermentation even before humans began to cook. By allowing microbial species to ferment and break down complex carbohydrates and other macromolecules in foods, we may have turned over certain parts of an otherwise energy-intensive digestive process to microbes in a form of "external digestion." This use of fermentation to pre-digest food, intentional or not, may have served as a predecessor to cooking, providing the extra calories needed to support the evolution of a larger brain.

Another benefit of fermentation is that it offered access to foods which, previously, would have been toxic. As our ancestors came down from the trees and needed new ways to fill their stomachs, the tubers of many plants and grasses offered an appealing, ready source of calories. Tubers contain large deposits of starch. Root vegetables, such as potatoes, yams, and carrots, are our modern-day, highly domesticated equivalents. But the wild tubers of our ancestors' time were hard to chew, and some contained low levels of toxins. Varieties of cassava, for example, contain compounds that release cyanide when ingested. After just a few days of fermentation, however, microbes destroy these dangerous molecules and make the food safe to eat.2