The scientific context for this shift is striking. Until the early 2000s, only a handful of scientific articles used the term microbiome; by 2025, more than 38,000 articles appeared in a single year, according to the U.S. National Library of Medicine. Biomedical scholarship has increasingly linked the gut microbiome to health, environment, lifestyle and socioeconomic status, while a public fascination the authors describe, following anthropologist Stefan Helmreich, as microbiomania has turned gut health into a key component of living well. This probiotic turn stands in stark contrast to the antibiotic era, when microbes were seen almost exclusively as pathogens to be exterminated through regimes of hygiene.

The authors situate this contrast historically. Western science only began to formally recognise microbes as central to human health in the mid-nineteenth century, when bacteriology and germ theory revealed invisible threats lurking in everyday contact, food and water. As historian Nancy Tomes has documented, Pasteurian germ theory recast human-microbe relations in terms of constant risk, creating a moral and practical imperative to pursue germ-free lives. With the arrival of antibiotics in the mid-twentieth century, this exterminatory approach became further entrenched. Yet the rise of antimicrobial resistance, drug-resistant superbugs, gut dysbiosis and antibiotic residues now widespread as environmental contaminants has exposed the long-term costs of that stance. The pathogenic imaginary, the authors write, has itself become pathological.

To move beyond this legacy, the study proposes metabolism as an analytic framework. Metabolism is familiarly understood as the chemical process that converts food into energy, but the authors, following scholars such as Hannah Landecker, Sophie Chao and Anthony Ryan Hatch, treat it as a lens that stitches together the molecular, the bodily and the planetary. Hatch’s politics of metabolism examines the ideas, social practices and institutional relationships that govern the metabolic health of individuals and groups, and argues that confining metabolism to individual bodies obscures the social determinants—race, class and access to healthcare—that shape metabolic health disparities. Applied to the microbiome, this framework foregrounds relational processes rather than bounded entities to be eradicated or optimised.

The empirical core of the study consists of three focus groups involving eight participants and twenty one-on-one interviews, conducted between October 2023 and May 2024 with students drawn from eight Australian universities. The sample included eighteen undergraduates, two Masters students and eight PhD students, aged mostly between 18 and 28 with a mean age of 23, comprising 19 women, 8 men and 1 non-binary participant. Microbiology students were recruited deliberately: as emerging adults responsible for their own health, as people fluent in the microbial lexicon, and as members of Generation Z, the generation set to inherit the challenges of the Anthropocene, from COVID-19 to antimicrobial resistance and rising chronic inflammatory disease.

One of the clearest findings concerns the collapse of the good-versus-bad-bugs dichotomy. Participants described how childhood lessons that all bacteria are bad gave way, through their scientific training, to a more relational understanding. One undergraduate noted that there is no such thing as a bad microbe, since microbes simply do what their genes tell them, while a PhD student explained that infection often reflects dysbiosis—an imbalance in an ecosystem where microbes normally keep each other in check—rather than the presence of an inherently evil organism. Participants extended this logic to hygiene, questioning the marketing of antibacterial products that kill 99.9 percent of bacteria, and noting that ordinary soap is sufficient while harsh agents can harm the skin’s own microbiota. The authors link this to Landecker’s critique of over-hygienisation, a paradox of modern microbial relations in which industrialised practices encourage hyper-sanitisation even as awareness grows that an exterminatory approach may damage health.

Perhaps the most philosophically striking theme was the holobiont: the concept that the host and its microbiome constitute a single entity. One undergraduate explained that essential chemicals for normal physiological function, such as serotonin, cannot be produced by humans at all but are made by the permanent colony of bacteria living within us, concluding that the microbiome is not a separate companion but, as the participant put it, just me. Yet the same participant also compared the microbiome to a pet, illustrating what the authors see as the struggle to fully incorporate this multitude within the self. Other participants described baking sourdough with home-grown cultures, tracing a symbiotic loop in which bacteria from their hands and kitchens shape the culture and the culture, in turn, shapes their gut health. The authors read these accounts as evidence of distributed selfhood and an expanded ontology in which the human body spills over into the ecosystem.

This multispecies awareness also disrupted modernist ideas of individual responsibility. Participants discussed the gut-brain axis, the bidirectional communication between intestinal microbes and the central nervous system, noting that microbes can send signals that influence cravings: eat a lot of carbohydrates and the bugs that break down carbohydrates multiply, prompting more carbohydrate cravings. One participant summarised the implication bluntly: blame the bugs, not me. Another reflected that learning about the microbiome would have relieved the childhood pressure of being told that body size was entirely a matter of personal fault, saying it is not just your fault, it is not anyone’s fault. The authors connect this to Hatch’s notion of metabolic labour, in which the body becomes a site of complex biological processes that defy clear lines of personal accountability, and to participants’ observations that microbes correlated with conditions such as anorexia and depression, not causatively but as contributing factors.

At the same time, the study documents how easily these liberating insights fold back into individualism and commerce. Participants were sceptical of the wellness industry that sells probiotics, supplements and lifestyle advice under the banner of gut health, with one noting that many probiotics do not actually work and that a healthy diet already supplies what the body needs. The authors draw on Landecker’s argument that the health industry has commodified microbial life, promising balance and boosted immunity often without scientific backing, and on research by Grosglik and Kotliar showing how computational sequencing renders microbes visible, commensurable and commodifiable as personalised products—a symbiotic singularity. To be a healthy subject, the study observes, is also to be a consuming subject, and even well-informed students reverted to utilitarian framings that privilege individual benefit over more-than-human connectedness.

Finally, the participants connected microbial health to global injustice. They described antimicrobial resistance as a wicked problem that interacts with other wicked problems: a warmer climate expands opportunities for bacteria to thrive, resistance is very high in less-developed countries, and diseases affecting poorer regions attract little research funding because there is not enough money in it. One participant traced how industrialised farming, keeping animals in dense hubs and dosing them with antibiotics, creates the selective pressure that drives resistance, concluding that humanity must reconsider whether its food production is sustainable. The authors argue that a politics of metabolism can make these uneven distributions visible, linking intimate bodily practices to industrial and planetary processes. Their conclusion is that the microbiome should be understood not merely as a site for individual health optimisation but as a site of sociopolitical significance, where health emerges from dynamic interactions between human and microbial agents—and where fostering holistic and just approaches to metabolic health requires engaging with the ethical, political and social dimensions of our entangled microbial lives.

Subject of Research: The social and political dimensions of human-microbiome relations and a politics of metabolism

Article Title: Metabolising microbes, meaning and modernity

Article References: Metabolising microbes, meaning and modernity. (n.d.). https://doi.org/10.1038/s41599-026-09242-0

Image Credits: AI Generated

DOI: 10.1038/s41599-026-09242-0

Keywords: microbiome, gut health, metabolism, holobiont, antimicrobial resistance, microbiopolitics, hygiene, biopolitics, multispecies, qualitative research, Generation Z, wellness industry