Summary: Researchers mapped the precise environmental and physical dynamics governing human microbiome transmission, proving that household cohabitation serves as the primary vector for strain-level bacterial colonization. The research team analyzed comprehensive oral and gastrointestinal metagenomic data from 430 individuals across 207 households spanning distinct geographic and cultural landscapes in Italy and Fiji.
The empirical tracking data shattered traditional genetic inheritance assumptions, revealing that individuals living under the same roof share vastly more microbial strains with one another than with the surrounding community, completely independent of biological kinship. Crucially, the trial exposed a dark metabolic link: the specific bacterial strains displaying the highest environmental transmissibility are structurally intertwined with biomarkers of Type 2 diabetes, poor cardiometabolic health, and colorectal oncogenesis.
