We need better protections for the community privacy risks involved with collecting personal health data, say microbiome researchers

When a person consents to sharing their health data, they may inadvertently reveal sensitive information about the people with whom they interact. For example, someone who submits an oral swab for analysis could expose shared microbial signatures that provide information about others in their orbit, without those individuals’ knowledge or consent. This is called a breach of relational privacy. 

In a commentary publishing in the Cell Press journal Trends in Microbiology on November 5, researchers at Yale University argue that the collection of biological data inherently involves relational privacy risks, and advancements in biomedical and data science are increasing the need for enhanced relational privacy protections. 

The team used the human microbiome—the collection of microorganisms that live on and in the body—to illustrate how an individual’s biological data might reflect that of the people around them. 

“Your microbiome is a sum of all your interactions,” says Bianca Brown of Yale and the University of Cambridge, UK. “Imagine if you swabbed everyone in your community. You’d find a clustering of microbiomes, generally depending on who is interacting with whom.” 

The closer the relationship between two people, the more their microbiomes overlap. For instance, partners, family members, friends, and neighbors tend to have more overlap than coworkers or classmates. 

Beyond uncovering social interactions, the microbiome can carry signatures of a person’s health and physiology. For example, during the COVID-19 pandemic, public health professionals used viral genome sequencing to trace community spread of SARS-CoV-2—but had to tailor their tracing methods to avoid impeding relational privacy. 

“It’s almost like a trade-off,” Brown says. “You’re giving up your privacy, or you’re giving up data, for the greater good of society.” 

Outside of a pandemic, however, relational privacy presents more complex bioethical concerns. Opportunities for health data misuse abound, from hospitals leveraging expansive datasets to consumers purchasing medical test kits and scientists studying communities. 

The team notes that existing privacy frameworks focus on individuals rather than communities. The federal Health Insurance Portability and Accountability Act (HIPAA), for example, treats family medical history as part of an individual’s protected health information. The Common Rule, which applies to human research subjects in the US, doesn’t include relational privacy protections. The international FAIR Guiding Principles, which provide a roadmap for the responsible management of scientific data, also fail to address relational privacy. 

“I don’t think we, as consumers, really understand what happens to our data when we give it away,” Brown says. 

Still, some existing regulations offer a blueprint for relational privacy policy. In Indigenous communities, the CARE Principles recognize that one person’s data may reflect that of a group. 

The researchers say that as the fields of both biomedical and data science rapidly advance, so too does the need for enhanced relational privacy protections. 

“As we learn more about how our social interactions shape the microbiome and its relevance to health, while collecting microbiome data at increasingly large scales, we need to better understand what these data can reveal,” Brown says. 

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This work was supported by the Rokos-Menon Visiting Senior Research Fellowship at Queens’ College, University of Cambridge; the Richter Summer Undergraduate Fellowship; and the Richard Lounsbery Foundation. 

Trends in Microbiology, Brown et al., “Microbiome sharing and the shift to relational privacy” https://www.cell.com/trends/microbiology/fulltext/S0966-842X(26)00276-3

Trends in Microbiology, (@TrendsMicrobiol) published by Cell Press, is a monthly review journal that provides a multidisciplinary forum for the discussion of all aspects of microbiology—from cell biology and immunology to genetics and evolution—and ranges across virology, bacteriology, protozoology, and mycology. Visit http://www.cell.com/trends/microbiology. To receive Cell Press media alerts, please contact press@cell.com.