October 2, 2023

Experts Debunk Scientific Claims That Human Babies Are Colonized by Bacteria Before Birth

To take a look at these claims, UCC & & APC Principal Investigator Prof. Jens Walter put together a trans-disciplinary group of 46 leading experts in reproductive biology, microbiome science, and immunology from around the globe to assess the proof for microbes in human fetuses.
University College Cork & & APC Microbiome Ireland Principal Investigator Prof. Jens Walter assembled a trans-disciplinary team of 46 leading specialists from around the globe to examine the proof for microorganisms in human fetuses. Credit: UCC.
A healthy human fetus is sterilized.
The team unanimously refuted the principle of a fetal microbiome and concluded that the detection of microbiomes in fetal tissues was due to contamination of samples drawn from the womb. Contamination took place throughout vaginal shipment, clinical procedures, or throughout laboratory analysis.
In the report in Nature, the international professionals motivate researchers to focus their studies on the microbiomes of moms and their newborn babies and on the microbial metabolites crossing the placenta which prepare the fetus for post-natal life in a microbial world.
According to Prof. Walter: “This agreement provides guidance for the field to progress, to focus research study efforts where they will be most effective. Knowing that the fetus remains in a sterile environment, confirms that colonization by bacteria occurs throughout birth and in early post-natal life, which is where therapeutic research study on modulation of the microbiome need to be focused.”.
The professional international authors also offer guidance on how scientists in the future can prevent risks of contamination in the analysis of other samples where microbes are expected to be missing or present at low levels, such as internal organs and tissues within the human body.
Reference: “Questioning the fetal microbiome and pitfalls of low-biomass microbial studies” 25 January 2023, Nature.DOI: 10.1038/ s41586-022-05546-8.

A team of specialists unanimously refuted the principle of a fetal microbiome and concluded that the detection of microbiomes in fetal tissues was due to the contamination of samples taken from the uterus. This contamination could have happened throughout vaginal birth, medical procedures, or during laboratory testing.
Leading specialists from numerous scientific disciplines find defects in studies that suggest the existence of a “fetal microbiome.”
Scientific claims that children harbor live germs while still in the womb are unreliable, and may have hampered research development, according to University College Cork (UCC) scientists at APC Microbiome Ireland, a world-leading Science Foundation Ireland (SFI) Research Centre, which led a perspective released today (January 25, 2023) in the prominent scientific journal Nature.
Prior claims that the human placenta and amniotic fluid are generally colonized by bacteria would, if true, have severe implications for medical medication and pediatrics. It would also weaken recognized principles in immunology and reproductive biology.