Andrew Flachs, Purdue University and Joseph Orkin, Université de Montréal

Many people around the world make and eat fermented foods. Millions in Korea alone make kimchi. The cultural heritage of these picklers shape not only what they eat every time they crack open a jar but also something much, much smaller: their microbiomes.

On the microbial scale, we are what we eat in very real ways. Your body is teeming with trillions of microbes. These complex ecosystems exist on your skin, inside your mouth and in your gut. They are particularly influenced by your surrounding environment, especially the food you eat. Just like any other ecosystem, your gut microbiome requires diversity to be healthy.

People boil, fry, bake and season meals, transforming them through cultural ideas of “good food.” When people ferment food, they affect the microbiome of their meals directly. Fermentation offers a chance to learn how taste and heritage shape microbiomes: not only of culturally significant foods such as German sauerkraut, kosher pickles, Korean kimchi or Bulgarian yogurt, but of our own guts.

Our work as anthropologists focuses on how culture transforms food. In fact, we first sketched out our plan to link cultural values and microbiology while writing our Ph.D. dissertations at our local deli in St. Louis, Missouri. Staring down at our pickles and lox, we wondered how the salty, crispy zing of these foods represented the marriage of culture and microbiology.

Equipped with the tools of microbial genetics and cultural anthropology, we were determined to find out.

Science and art of fermentation

Fermentation is the creation of an extreme microbiological environment through salt, acid and lack of oxygen deprivation. It is both an ancient food preservation technique and a way to create distinctive tastes, smells and textures.

Taste is highly variable and something you experience through the layers of your social experience. What may be nauseating in one context is a delicacy in another. Fermented foods are notoriously unsubtle: they bubble, they smell and they zing. Whether and how these pungent foods taste good can be a moment of group pride or a chance to heal social divides.

In each case, cultural notions of good food and heritage recipes combine to create a microbiome in a jar. From this perspective, sauerkraut is a particular ecosystem shaped by German food traditions, kosher dill pickles by Ashkenazi Jewish traditions, and pao cai by southwestern Chinese traditions.

Where culture and microbiology intersect

To begin to understand the effects of culinary traditions and individual creativity on microbiomes, we partnered with Sandor Katz, a fermentation practitioner based in Tennessee. Over the course of four days during one of Katz's workshops, we made, ate and shared fermented foods with nine fellow participants. Through conversations and interviews, we learned about the unique tastes and meanings we each brought to our love of fermented foods.

Those stories provided context to the 46 food samples we collected and froze to capture a snapshot of the life swimming through kimchi or miso. Participants also collected stool samples each day and mailed in a sample a week after the workshop, preserving a record of the gut microbial communities they created with each bite.

The fermented foods we all made were rich, complex and microbially diverse. Where many store-bought fermented foods are pasteurized to clear out all living microbes and then reinoculated with two to six specific bacterial species, our research showed that homemade ferments contain dozens of strains.

On the microbiome level, different kinds of fermented foods will have distinct profiles. Just as forests and deserts share ecological features, sauerkrauts and kimchis look more similar to each other than yogurt to cheese.

But just as different habitats have unique combinations of plants and animals, so too did every crock and jar have its own distinct microbial world because of minor differences in preparation or ingredients. The cultural values of taste, creativity and style that create a kimchi or a sauerkraut go on to support distinct microbiomes on those foods and inside the people who eat them.

Through variations in recipes and cultural preferences toward an extra pinch of salt or a disdain for dill, fermentation traditions result in distinctive microbial and taste profiles that your culture trains you to identify as good or bad to eat. That is, our sauerkraut is not your sauerkraut, even if they both might be good for us.

Fermented food as cultural medicine

Microbially rich fermented foods can influence the composition of your gut microbiome. Because your tastes and recipes are culturally informed, those preferences can have a meaningful effect on your gut microbiome. You can eat these foods in ways that introduce microbial diversity, including potentially probiotic microbes that offer benefits to human health such as killing off bacteria that make you ill, improving your cardiovascular health or restoring a healthy gut microbiome after you take antibiotics.

Fermentation is an ancient craft, and like all crafts it requires patience, creativity and practice. Cloudy brine is a signal of tasty pickled cucumbers, but it can be a problem for lox. When fermented foods smell rotten, taste too soft or turn red, that can be a sign of contamination by harmful bacteria or molds.

Fermenting foods at home might seem daunting when food is something that comes from the store with a regulatory guarantee. People hoping to take a more active role in creating their food or embracing their own culture's traditional foods need only time, water and salt to make simple fermented foods. As friends share sourdough starters, yogurt cultures and kombucha mothers, they forge social connections.

Through a unique combination of culture and microbiology, heritage food traditions can support microbial diversity in your gut. These cultural practices provide environments for the yeasts, bacteria and local fruits and grains that in turn sustain heritage foods and flavors.

Andrew Flachs, Associate Professor of Anthropology, Purdue University and Joseph Orkin, Assistant Professor of Anthropology, Université de Montréal

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Fabian Klenner, University of Washington

Saturn has 146 confirmed moons – more than any other planet in the solar system – but one called Enceladus stands out. It appears to have the ingredients for life.

From 2004 to 2017, Cassini – a joint mission between NASA, the European Space Agency and the Italian Space Agency – investigated Saturn, its rings and moons. Cassini delivered spectacular findings. Enceladus, only 313 miles (504 kilometers) in diameter, harbors a liquid water ocean beneath its icy crust that spans the entire moon.

Geysers at the moon's south pole shoot gas and ice grains formed from the ocean water into space.

Though the Cassini engineers didn't anticipate analyzing ice grains that Enceladus was actively emitting, they did pack a dust analyzer on the spacecraft. This instrument measured the emitted ice grains individually and told researchers about the composition of the subsurface ocean.

As a planetary scientist and astrobiologist who studies ice grains from Enceladus, I'm interested in whether there is life on this or other icy moons. I also want to understand how scientists like me could detect it.

Ingredients for life

Just like Earth's oceans, Enceladus' ocean contains salt, most of which is sodium chloride, commonly known as table salt. The ocean also contains various carbon-based compounds, and it has a process called tidal heating that generates energy within the moon. Liquid water, carbon-based chemistry and energy are all key ingredients for life.

In 2023, I and others scientists found phosphate, another life-supporting compound, in ice grains originating from Enceladus' ocean. Phosphate, a form of phosphorus, is vital for all life on Earth. It is part of DNA, cell membranes and bones. This was the first time that scientists detected this compound in an extraterrestrial water ocean.

Enceladus' rocky core likely interacts with the water ocean through hydrothermal vents. These hot, geyserlike structures protrude from the ocean floor. Scientists predict that a similar setting may have been the birthplace of life on Earth.

Detecting potential life

As of now, nobody has ever detected life beyond Earth. But scientists agree that Enceladus is a very promising place to look for life. So, how do we go about looking?

In a paper published in March 2024, my colleagues and I conducted a laboratory test that simulated whether dust analyzer instruments on spacecraft could detect and identify traces of life in the emitted ice grains.

To simulate the detection of ice grains as dust analyzers in space record them, we used a laboratory setup on Earth. Using this setup, we injected a tiny water beam that contained bacterial cells into a vacuum, where the beam disintegrated into droplets. Each droplet contained, in theory, one bacterial cell.

Then, we shot a laser at the individual droplets, which created charged ions from the water and the cell compounds. We measured the charged ions using a technique called mass spectrometry. These measurements helped us predict what dust analyzer instruments on a spacecraft should find if they encountered a bacterial cell contained in an ice grain.

We found these instruments would do a good job identifying cellular material. Instruments designed to analyze single ice grains should be able to identify bacterial cells, even if there is only 0.01% of the constituents of a single cell in an ice grain from an Enceladus-like geyser.

The analyzers could pick up a number of potential signatures from cellular material, including amino acids and fatty acids. Detected amino acids represent either fragments of the cell's proteins or metabolites, which are small molecules participating in chemical reactions within the cell. Fatty acids are fragments of lipids that make up the cell's membranes.

In our experiments, we used a bacteria named Sphingopyxis alaskensis. Cells of this culture are extremely tiny – the same size as cells that might be able to fit into ice grains emitted from Enceladus. In addition to their small size, these cells like cold environments, and they need only a few nutrients to survive and grow, similar to how life adapted to the conditions in Enceladus' ocean would probably be.

The specific dust analyzer on Cassini didn't have the analytical capabilities to identify cellular material in the ice grains. However, scientists are already designing instruments with much greater capabilities for potential future Enceladus missions. Our experimental results will inform the planning and design of these instruments.

Future missions

Enceladus is one of the main targets for future missions from NASA and the European Space Agency. In 2022, NASA announced that a mission to Enceladus had the second-highest priority as they picked their next big missions – a Uranus mission had the highest priority.

The European agency recently announced that Enceladus is the top target for its next big mission. This mission would likely include a highly capable dust analyzer for ice grain analysis.

Enceladus isn't the only moon with a liquid water ocean. Jupiter's moon Europa also has an ocean that spans the entire moon underneath its icy crust. Ice grains on Europa float up above the surface, and some scientists think Europa may even have geysers like Enceladus that shoot grains into space. Our research will also help study ice grains from Europa.

NASA's Europa Clipper mission will visit Europa in the coming years. Clipper is scheduled to launch in October 2024 and arrive at Jupiter in April 2030. One of the two mass spectrometers on the spacecraft, the SUrface Dust Analyzer, is designed for single ice grain analysis.

Our study demonstrates that this instrument will be able to find even tiny fractions of a bacterial cell, if present in only a few emitted ice grains.

With these space agencies' near-future plans and the results of our study, the prospects of upcoming space missions visiting Enceladus or Europa are incredibly exciting. We now know that with current and future instrumentation, scientists should be able to find out whether there is life on any of these moons.

Fabian Klenner, Postdoctoral Scholar in Earth and Space Sciences, University of Washington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Alexander L. Metcalf, University of Montana

Montanans know spring has officially arrived when grizzly bears emerge from their dens. But unlike the bears, the contentious debate over their future never hibernates. New research from my lab reveals how people's social identities and the dynamics between social groups may play a larger role in these debates than even the animals themselves.

Social scientists like me work to understand the human dimensions behind wildlife conservation and management. There's a cliché among wildlife biologists that wildlife management is really people management, and they're right. My research seeks to understand the psychological and social factors that underlie pressing environmental challenges. It is from this perspective that my team sought to understand how Montanans think about grizzly bears.

To list or delist, that is the question

In 1975, the grizzly bear was listed as threatened under the Endangered Species Act following decades of extermination efforts and habitat loss that severely constrained their range. At that time, there were 700-800 grizzly bears in the lower 48 states, down from a historic 50,000. Today, there are about 2,000 grizzly bears in this area, and sometime in 2024 the U.S. Fish and Wildlife Service will decide whether to maintain their protected status or begin the delisting process.

Listed species are managed by the federal government until they have recovered and management responsibility can return to the states. While listed, federal law prevents hunting of the animal and destruction of grizzly bear habitat. If the animal is delisted, some states intend to implement a grizzly bear hunting season.

People on both sides of the delisting debate often use logic to try to convince others that their position is right. Proponents of delisting say that hunting grizzly bears can help reduce conflict between grizzly bears and humans. Opponents of delisting counter that state agencies cannot be trusted to responsibly manage grizzly bears.

But debates over wildlife might be more complex than these arguments imply.

Identity over facts

Humans have survived because of our evolved ability to cooperate. As a result, human brains are hardwired to favor people who are part of their social groups, even when those groups are randomly assigned and the group members are anonymous.

Humans perceive reality through the lens of their social identities. People are more likely to see a foul committed by a rival sports team than one committed by the team they're rooting for. When randomly assigned to be part of a group, people will even overlook subconscious racial biases to favor their fellow group members.

Leaders can leverage social identities to inspire cooperation and collective action. For example, during the COVID-19 pandemic, people with strong national identities were more likely to physically distance and support public health policies.

But the forces of social identity have a dark side, too. For example, when people think that another “out-group” is threatening their group, they tend to assume members of the other group hold more extreme positions than they really do. Polarization between groups can worsen when people convince themselves that their group's positions are inherently right and the other group's are wrong. In extreme instances, group members can use these beliefs to justify immoral treatment of out-group members.

Empathy reserved for in-group members

These group dynamics help explain people's attitudes toward grizzly bears in Montana. Although property damage from grizzly bears is extremely rare, affecting far less than 1% of Montanans each year, grizzly bears have been known to break into garages to access food, prey on free-range livestock and sometimes even maul or kill people.

People who hunt tend to have more negative experiences with grizzly bears than nonhunters – usually because hunters are more often living near and moving through grizzly bear habitat.

In a large survey of Montana residents, my team found that one of the most important factors associated with negative attitudes toward grizzly bears was whether someone had heard stories of grizzly bears causing other people property damage. We called this “vicarious property damage.” These negative feelings toward grizzly bears are highly correlated with the belief that there are too many grizzly bears in Montana already.

But we also found an interesting wrinkle in the data. Although hunters extended empathy to other hunters whose properties had been damaged by grizzly bears, nonhunters didn't show the same courtesy. Because property damage from grizzly bears was far more likely to affect hunters, only other hunters were able to put themselves in their shoes. They felt as though other hunters' experiences may as well have happened to them, and their attitudes toward grizzly bears were more negative as a result.

For nonhunters, hearing stories about grizzly bears causing damage to hunters' property did not affect their attitudes toward the animals.

Identity-informed conservation

Recognizing that social identities can play a major role in wildlife conservation debates helps untangle and perhaps prevent some of the conflict. For those wishing to build consensus, there are many psychology-informed strategies for improving relationships between groups.

For example, conversations between members of different groups can help people realize they have shared values. Hearing about a member of your group helping a member of another group can inspire people to extend empathy to out-group members.

Conservation groups and wildlife managers should take care when developing interventions based on social identity to prevent them from backfiring when applied to wildlife conservation issues. Bringing up social identities can sometimes cause unintended division. For example, partisan politics can unnecessarily divide people on environmental issues.

Wildlife professionals can reach their audience more effectively by matching their message and messengers to the social identities of their audience. Some conservation groups have seen success uniting community members who might otherwise be divided around a shared identity associated with their love of a particular place. The conservation group Swan Valley Connections has used this strategy in Montana's Swan Valley to reduce conflict between grizzly bears and local residents.

Group dynamics can foster cooperation or create division, and the debate over grizzly bear management in Montana is no exception. Who people are and who they care about drives their reactions to this large carnivore. Grizzly bear conservation efforts that unite people around shared identities are far more likely to succeed than those that remind them of their divisions.

Alexander L. Metcalf, Associate Professor of Human Dimensions of Natural Resources, University of Montana

This article is republished from The Conversation under a Creative Commons license. Read the original article.