Comprehensive human amniotic fluid metagenomics supports the sterile womb hypothesis.
Level 4 - case-series / case-control
Cross-sectional laboratory analysis of human biological specimens.
PubMed 35477737 · doi:10.1038/s41598-022-10869-7
What was done
Researchers developed a metagenomic sequencing workflow designed for low-volume samples that controlled for exogenous background contamination from water, reagents, and laboratory environments. This method and detection criteria were applied to human mid-gestational amniotic fluid samples to test for the presence of microbial and viral nucleic acids.
What was found
The abstract reports that mid-gestational amniotic fluid had no detectable virome or microbiome once exogenous contaminants were accounted for. No quantitative data (such as sample counts, sequencing depth, or detection thresholds) are provided in the abstract.
Why it matters
These findings provide methodological and empirical evidence supporting the sterile womb hypothesis, suggesting that previous detections of amniotic fluid microbes may have been driven by low-biomass background contamination.
Limits
The abstract does not state the sample size, clinical characteristics of the donors, exact gestational timing, sequencing depth, or analytical sensitivity. Findings are limited to mid-gestational fluid and do not assess other stages of pregnancy.
Cited by
- supports Human infants are born sterile and acquire their gut microbiome postnatally from immediate surroundings and parents.