The person-to-person transmission landscape of the gut and oral microbiomes.
Level 3 - non-randomized controlled study
Large-scale observational cohort metagenomic analysis across populations (design analogy).
PubMed 36653448 · doi:10.1038/s41586-022-05620-1
What was done
The authors performed computational strain-level profiling on over 9,700 human metagenomes to assess person-to-person bacterial strain sharing across mother-to-infant, intra-household, and population-level contexts for gut and oral microbiomes.
What was found
The authors identified over 10 million instances of bacterial strain sharing. Mother-to-infant gut microbiome strain-sharing rate was around 50% during infancy and persisted at older ages. Horizontal transmission was prominent in the oral microbiome and increased with cohabitation duration. Cohabiting individuals had median strain-sharing rates of 12% for gut and 32% for oral microbiomes, with cohabitation duration having a greater impact on sharing than age or host genetics.
Why it matters
This work demonstrates that horizontal and vertical interpersonal transmission substantially shapes individual microbiome composition, suggesting that microbiome-associated non-communicable conditions could have an overlooked transmissible component.
Limits
The abstract does not specify the exact number of human participants (only reporting >9,700 metagenomes) nor the specific geographic cohorts included. Findings rely on computational metagenomic inference of strain sharing rather than direct experimental observation of live bacterial transfer.
Cited by
- supports The bacterial composition of the oral microbiome is distinct from and not similar to the gut/digestive microbiome.