Abstract
Thinking of the gut microbiome as part of the foodscape reorients us to a food justice perspective on equality and access to human health and flourishing.
One August day just after noon, a rusting van pulled up to the curb of a quiet side street in a ‘60s-era inner-suburb of Toronto. Cardboard boxes of fresh fruits and vegetables were stacked to the van’s roof. Two men quickly opened the doors and laid out the boxes on the sidewalk boulevard, where a group of several dozen women, children, and men had begun to gather.
The crowd chatted in Gujarati as they inspected the foods for sale. Fresh bottle gourd, grapes, bitter melon, okra, and big bunches of fenugreek. “It’s a very low price,” one woman told me when I asked why she shopped there. Indeed, I spotted a bunch of fresh coriander for only $1 that would cost me about $3 at the store in my area.
This mobile market was just one part of an informal distribution system making fresh produce easily available to people living in Toronto’s lower-income communities, where a supermarket can be a long walk, bus, or car ride away. My team at the Food Health Ecosystems Lab has documented many more informal sellers, learning of them through word of mouth or by coming across them unexpectedly. Mostly, they have been overlooked as part of the city’s foodscape, but I center them in my analysis in order to broaden the understanding of food and foodscapes—specifically when contemplating new research in the biomedical sciences about the human gut microbiome. In effect, I connect the foodscape—the places where we procure food and the spaces where we learn about food, prepare, and consume it—to the microscapes of our own human guts.
New research into the human gut microbiome in the biomedical and natural sciences is shifting understandings of healthy eating and complicating what we know about the food system. In so doing, it is redefining what it means to eat healthy. Not only do we need food that nourishes our bodies, it turns out the food we eat must feed our resident communities of microorganisms—communities we now know are fundamental determinants of human health. This science is raising questions for sociologists, especially about how foodscapes support microbial health and about who has (or does not have) access to microbial health-promoting conditions.
Foodscapes are not neutral spaces. They reflect broader social structures. We know, for instance, that what we eat is determined in large part by how much money we have, what kind of food we can buy with it, where we live, and what food is available nearby. These factors are shaped by race, class, gender, ability, immigration status, indigeneity, and other social determinants. With our microbial health significantly dependent on what we eat, one can draw a straight line between foodscapes and the health of the human microbiome. I argue that thinking of the gut microbiome as part of the food system counters current trends toward the privatization and commercialization of emerging knowledge about the microbiome, reorienting it toward food justice—and rendering a food justice approach to gut health crucial to ensuring access to the conditions that support all bodies and communities.
More than Human
The way I see it, bacteria and other microorganisms that live within us and comprise our microbiomes are nonhuman food system actors. These smaller lifeforms play a central role in keeping our bodies nourished. We might think of them like the pollinators that ensure plants produce food for us to eat or the soil biota, like nematodes, that bring life to the earth in which food plants grow. These other lifeforms underpin the ecological processes that ultimately transform the sun’s energy into a bean, a piece of cheese, or a chicken drumstick. Similarly, the human microbiome is key to health. It is an ecological determinant of health—part of the ecological systems that underpin life on this planet. Communities of microorganisms live in our digestive tracts, on our skin, and in all our orifices including eyes, ears, and reproductive organs. But because I study the food system, I focus on the gut microbiome and its linear connection to what we eat. I visualize a food system starting on the farm and ending not with food on the plate, but food, consumed, moving through our digestive tracts, and worked upon by microorganisms. (Keep in mind: separating out these gut critters from the rest of the human and earth microbiome is more of a conceit for the sake of argument, as in reality they are all interconnected.)
Scientists at the University of Arkansas System Division of Agriculture’s Center for Food Safety examine microbial colonies.
AAES Director, Flickr CC
Recent advances have enabled microbiologists and others to uncover the significant role that resident microorganisms play in our bodies. An explosion of research on the human microbiome is putting together a new understanding of microbes and human health. Among other fascinating things, scholars have found that microorganisms are integral to our immune systems. They are able to turn human genes on and off, modulate our metabolism, produce things called metabolites that reduce inflammation in our bodies, and even contribute to brain function. Disruption to healthy microbial communities, sometimes called dysbiosis, has been connected to the presentation of diseases like rheumatoid arthritis, cardiovascular disease, Crohn’s disease, acne, irritable bowel syndrome, and depression and anxiety. While some microorganisms are pathogenic and cause disease and sickness—anyone who has had food poisoning knows this, well, in their gut—the research shows that bacteria have gotten a bad rap. Turns out, we can’t live without them.
Thinking of the gut microbiome as part of the food system reorients us to a food justice perspective on human health and flourishing.
Sheila Sund, Flickr CC
Consider just one of the food-related roles our resident microorganisms play: turning the fibers in food that are indigestible by our bodies into short chain fatty acids that prove key to our health. Whole grains like brown rice and millet and vegetables such as leeks and asparagus contain microbiota-accessible carbohydrates (called MACs) that the human parts of our digestive systems cannot digest. Because our guts are more-than-human, the resident life forms consume the MACs, provide nutrition, and do things like make butyrate, a metabolite that reduces inflammation in our bodies. Researchers continue to make discoveries about these interspecies relationships, often using mice in their studies but also in human trials and using new technologies.
Human-microbial processes take place inside our bodies because we have co-evolved with microorganisms that existed on this planet for billions of years before humans. However, the way we live today—in cities where we are separated from ecosystems like wetlands, soils, and forests; eating processed foods; and doing things that kill bacteria such as taking antibiotics—has greatly diminished the diversity of gut microorganisms. By studying the feces of people who live in non-industrialized environments, such as foragers in Nepal, Indigenous people who live in the Amazon, and nomadic peoples in Tanzania, microbiologists have found whole species of bacteria that the guts of people who live in industrialized societies don’t have. Thus, the scientific literature differentiates between what is known as the “industrialized microbiome” and the “traditional microbiome” of people living outside industrialized settings. Though it’s beyond the scope of this essay, it’s important to note that studying the microbiomes of Indigenous peoples has been critiqued as being colonial and extractive. The language used to report on microbiome research is ripe for sociological analysis. Further, anytime data is generated from Indigenous bodies, there are important ethical questions about whose interests are served, whose health, power, and purses the practice enriches.
So far, comparative studies of microbiota have yielded an enormous trove of knowledge. Migration, for example, is now known to change the microbiome. The first large-cohort study of the impact of migration to the United States on people’s microbiome tracked Hmong and Karen newcomers from Southeast Asia and compared them to both U.S. residents of the same communities and to Euro-Americans. The researchers documented how migration between societies with different levels of industrialization causes the extinction or reduction of certain kinds of microorganisms.
Urban life, consumption of ultra-processed foods, and medical practices such as overreliance on antibiotics and C-section births all functionally select for an “industrial microbiota.” And that has serious health implications. Justin L. Sonnenburg and Erica D. Sonnenburg, whose Stanford University lab studies intestinal microbiota, wrote in the journal Science in 2019: “Given the large global health impact, strategies to protect the microbiome in all populations should be considered to maximize the palette of microbial and molecular tools available.” To protect the conditions that promote human health, they call for gut biota conservation and sustainability efforts.
Here food is key. Many of us eat differently today than people did a few generations ago, in part because of a rise in ultra-processed food products (a category described by the Food and Agriculture Organization of the United Nations as being made from “substances extracted from foods or derived from food constituents”). At the supermarket, ultra-processed foods are the packages with long lists of ingredients that are hard to pronounce. These include baked goods, hot dogs, breakfast cereals, even salad dressings and frozen meals. They contain emulsifiers like polysorbate 80, carboxymethylcellulose (CMC), and maltodextrin, as well as artificial sugars, shown to promote inflammation of the intestines, where so many of our microbes live. This is, perhaps, a long way of saying that gut microbiota depend on what the human host consumes—what we choose to put in our mouths in part determines which ecosystem services we get from our resident bacteria.
If our diet supports the kinds of microbes that make inflammation-reducing metabolites, then we benefit. This is why I argue that the micro-biome should be considered to be part of the food system. It is inextricably part of the nested ecosystems of the biosphere that support human health through nutrition. From a more-than-human perspective, the drop in human gut biodiversity means we have lost health-supporting food system actors.
The idea that nonhuman critters are part of the food system and are responsible for keeping people healthy is not usually factored into the way mainstream society conceives of health when it comes to food. We tend toward arguments about nutrition and think of food justice in terms of people’s access to healthier food choices—what’s available and what’s affordable within a person’s foodscape. But other parts of the food system that work to produce healthy food, such as soil and water systems, biodiversity, a steady climate, are often left out of the picture when we think about healthy food. A growing body of work in fields such as geography, ecological public health, and rural sociology is, however, building out our understanding of a more holistic foodscape and changing how we see food justice.
Microbiomania
Fascinating discoveries about the human microbiome are quickly being turned into patents and products. Where university science and the food industry frame gut health as an individual issue, rather than as a community or social issue connected to the food system, we see the gut being privatized and commercialized. In the medical literature it is often suggested that discoveries can lead to personalized medicine and individualized nutrition. There are hundreds of patents in the Canadian Intellectual Property Database for various products that aim to monetize research. A trip to the natural food store can confirm that there are dozens of products, from probiotic supplements to “gut shots” (bacteria-packed liquid to drink) and chewing gum, that aim to package microbes and sell them to people looking for a personal health boost. The term “microbiomania” has been used by journalists to capture the zeal.
Sociologists in many fields, including those who study health and medicine, have long documented the role of discourse and the framing of ideas in shaping the way people make sense of the world. Understanding the microbiome as part of the food system shifts the discourse.
Thinking of the gut microbiome as being not only an ecological determinant of health but a part of the food system refocuses away from highly classed and racialized individual health and health discourses around purity and “clean eating.” It reorients attention toward the broader social benefits of the science and introduces a different way of thinking about food and health—in particular, the relationship between our health, the foodscape, and food justice.
Understanding the microbiome as part of the food system shifts the discourse.
This is not about equal access to a fad diet. The foods that are beneficial for our personal microbial ecosystems are the same foods that are recommended by science-informed dietary guidelines such as Canada’s Food Guide and the insight papers on sustainable food systems for Nordic countries published by the Stockholm Resilience Centre. The way of eating promoted by the EAT Lancet Commission, an independent scientific body that laid out steps for improving both human and planetary health through diet, is similar. All these dietary recommendations suggest eating foremostly plant foods such as vegetables, fruits, whole grains, and legumes, and avoiding highly processed food products. While it may be a simple prescription on paper, when superimposed onto the foodscape, where access to these kinds of foods is unequal and determined by social factors, we begin to see rampant inequality. This healthier way to eat is not available to everyone. That’s food injustice.
Researchers have begun to document how, for instance, moving between societies with different levels of industrialization affects individuals’ mircobiomes.
Neville Wootton, Piktour U.K., Flickr CC
Food Justice and Microbial Inequality
University researchers who study food systems have connected the foodscape with diet-related human health outcomes. As I noted earlier, the foodscape includes the physical spaces where people access food (stores, but also non-market spaces such as vegetable gardens and food banks) as well as the economic and social contexts that shape how people make decisions about what to eat and how to prepare and consume it. Scholars have found that the foodscape, working in tandem with other social factors, helps determine what people eat. This, in turn, has health impacts. For example, research has connected an unhealthy retail foodscape, such as a preponderance of fast food, with a higher incidence of cardiovascular disease. It’s also been found that people’s experiences of the foodscape differs based on who they are—specifically their race (see, for instance, Ken Kolb’s Retail Inequality).
Food justice is an approach used to elucidate current problems of inequality and injustice. For instance, food insecurity is an unevenly experienced social condition. Race and ethnicity correlate with food insecurity. In the United States, Black and Latinx communities suffer from more food insecurity than Whites. In Toronto, Canada, where I conduct my research, Black families are 3.5 times more likely not to have access to food than are White families. Also, in Canada, 48% of on-reserve Indigenous households experience income-related food insecurity—that’s 4 times higher than the rate in the Canadian non-Indigenous population. Statistics like these illustrate how inequalities are racialized and, in the words of Black Food Matters editors Hanna Garth and Ashante M. Reese, “deeply entrenched systemic processes.” Food justice aims to fix this social inequality through food.
A group of scholars, publishing together as The Microbes and Social Equity Working Group, have written about their desire to bring social justice to the microbiome. In one paper, they ask the important question of whether “we have a right to access and use microorganisms, much in the way that we have a right to access natural environments and the publicly shared environmental resources we require to live.” In 2022, another article flagged what the authors saw as important social questions for microbiome research. They observed that there are “structural inequalities” in the food system that prevent consumers’ microbiomes from flourishing. If one considers microbial equity through a food justice lens, it means making connections between the foodscape and the opportunities it provides for supporting gut health. We increasingly know what kinds of foods best support the conditions for microbial health—fresh fruits and vegetables, legumes, nuts, and whole grains—and my lab is investigating the ways the foodscape shapes the conditions for microbial health.
For example, some of my own lab’s initial findings have identified the informal vegetable peddlers in our city, those you met in the introduction of this paper, as one category of gut health supporting actors in the foodscapes of some lower-income neighborhoods. These micro-entrepreneurs purchase produce at the wholesale market and sell it from their trucks. They travel across the larger metropolitan area, laying out their boxes curbside on busy roads, on side streets, in parking lots, and, as I found in one interview, at a picnic bench on the lawn of social housing community. Mobile fresh produce markets like these provide affordable, culturally appropriate, gut-beneficial plant foods and therefore constitute population health-supporting infrastructure. Because we know that a diet diverse in fruits and vegetables supports healthier communities of microbiota, it can be inferred that these spaces provide people with the opportunity to access an important part of a diet that is good for the gut. The peddler market is therefore a gut-health supporting part of the foodscape.
By no means are these small businesses the only food system actors that have the potential to support microbial equity. However, they provide an opportunity to ponder the role of the foodscape in producing the conditions for food justice.
If we consider the human microbiome to be part of the food system, and we see value in microbial equity that would provide everyone with similar access to the conditions that support health—regardless of race or class or any other social determinant—then we need to think beyond the individual. Considering the human gut microbiome from this systems vantage point affords a view of health that is interconnected with both ecological systems and social ones. It is a reminder that healthy eating is dependent on a lot more than what you choose to eat for lunch. It is dependent on the entire food system, and social structures, to produce the conditions for health—something everyone one of us has a right to access.