The people you live with could be changing your gut bacteria

Spending time with close companions might do more than strengthen bonds—it could also reshape your gut bacteria. In a study of island birds, those with stronger social ties shared more gut microbes, especially types that require direct contact to spread. This suggests that social interaction itself—not just shared space—drives microbial exchange. The same process may be happening in human households through everyday closeness.

source https://www.sciencedaily.com/releases/2026/04/260413043131.htm