Your Gut Health May Be Influenced by People Around You: Study Shows

What if the people you live with are quietly shaping your gut health every single day?

A new study from the University of East Anglia suggests that close social relationships may influence the composition of your gut microbiome. Published in Molecular Ecology, the research found that individuals who interact frequently tend to share more similar gut bacteria—an effect observed in birds but highly relevant to humans.

Researchers analyzed fecal samples collected over several years, tracking how gut microbes spread among birds with different social roles—such as breeding pairs, helpers, and non-group members. The findings revealed a clear pattern: birds that spent more time together, particularly at the nest, shared significantly more gut bacteria.

Notably, the transfer involved anaerobic microbes—bacteria that cannot survive in oxygen-rich environments. This means they are unlikely to spread through air or the broader environment, but instead require close, direct contact. Activities like grooming, feeding, and nesting together appeared to facilitate this microbial exchange.

These findings reinforce earlier human studies showing that couples and long-term housemates often have more similar gut microbiomes than unrelated individuals, even when their diets differ. The new research strengthens the idea that physical closeness—such as touching, sharing spaces, and daily interactions—plays a major role in shaping gut bacteria.

This has important implications for health. Gut microbes are essential for digestion, immune function, and overall well-being. Sharing beneficial bacteria within households could potentially support better health outcomes, while also highlighting how lifestyle and relationships influence biology in subtle ways.

Although the study was conducted in birds, the parallels to human life are striking. It suggests that everyday interactions—whether it’s sharing meals, hugging, or simply living together—may gradually align the microscopic ecosystems within us, revealing a deeper biological connection between people than previously understood.

REFERENCE: Chuen Zhang Lee, Sarah F. Worsley, Terry Burke, Jan Komdeur, Falk Hildebrand, Hannah L. Dugdale, David S. Richardson. Social Structure and Interactions Differentially Shape Aerotolerant and Anaerobic Gut Microbiomes in a Cooperative Breeding Species. Molecular Ecology, 2026; 35 (7) DOI: 10.1111/mec.70304