Debates about obesity in bioethics tend to unfold in predictable epicycles between individual choices and behaviours (e.g., restraint, diet, exercise) and the oppressive socio-economic structures constraining them (e.g., food deserts, advertising). Here, we argue that recent work from two cutting-edge research programmes in microbiology and social psychology can advance this conceptual stalemate in the literature. We begin in section 1 by discussing two promising lines of obesity research involving the human microbiome and relationship partners. Then, in section 2, we show how this research has made viable novel strategies for fighting obesity, including microbial therapies and dyad-level interventions. Finally, in section 3, we consider objections to our account and conclude by arguing that attention to the most immediate features of our biological and social environment offers a middle ground solution, while also raising important new issues for bioethicists.
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For obvious reasons, a key variable in early studies on mice involved keeping the two populations separate—no cohousing condition between germ free versus conventionally raised—to rule out the transfer of microbiota through faecal matter.
In fact one could argue that, in their search for mechanistic explanations, the early studies on probiotics and obesity have downplayed the complexity of ecological relations between host and microbiome and between microbe and microbe as if there is a universal probiotic that shields us from gaining weight. A more realistic approach would not assume that bacteria in our gut exist in a vacuum, but that our metabolic responses are a function of community composition and of the relative abundances among various taxa (Ley et al. 2006).
In addition to the fact that social and political aspects of obesity are consistent with research on the human microbiome, we also suggest that when our proposals are presented in tandem, they provide an even stronger sense of how experiences of injustice can truly get under one’s skin and profoundly alter biological processes. Hertzman and Boyce (2010, 330) call this “biological embedding,” and one’s microbiome is a privileged site to witness the causal effects of socioeconomic factors on one’s own biology.
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Thanks to Anne Barnhill, Jason Robert, Brendan Bohannan, Walter Sinnott-Armstrong, Jana Schaich Borg, and Grainne Fitzsimmons for their feedback on earlier drafts of this manuscript. Special thanks also to our anonymous reviewers at this journal for their constructive suggestions. Over the years, the authors have found tremendous inspiration in Daniel Callahan’s work and especially, for this article, in his late publications. Dan passed away in 2019 and we would like to dedicate this article to him. Even if here we are challenging his views on obesity, we will always continue to look up to his life and to his work as a generous and inspirational model for bioethics.
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Joshua August Skorburg is co-first author
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Morar, N., Skorburg, J.A. Why We Never Eat Alone: The Overlooked Role of Microbes and Partners in Obesity Debates in Bioethics. Bioethical Inquiry 17, 435–448 (2020). https://doi.org/10.1007/s11673-020-10047-2
- Obesity in bioethics
- Human microbiome
- Relationship science
- Social psychology
- Food ethics