When foetus is initially exposed to germs
A baby’s immune system is prepared to endure in a germ-filled environment when a baby is born. This process of development is crucial for the health of the newborn as well as for lifetime growth.
Specifically, scientists do not agree on when the foetus is first exposed to microbes.
However, we only have a very limited grasp of the procedure. In particular, there is disagreement among expert as to when the foetus is initially exposed to germs.
In the past, scientists held the belief that the foetus, the womb is which it develops, the placenta, and the amniotic fluid(the fluid surrounding the embryo), are all sterile.
However, when DNA sequencing became available, multiple research teams discovered proof of microbial communities in the placenta and amniotic fluid.
These microbiomes(= community of bacteria fungus and virus) may be a normal component of pregnancy, and may expose the foetus to living microorganisms that strengthen its immune system.
To examine these claims, UCC-APC Principal Investigator Prof. Jens Walter assembled a trans-disciplinary teams of 46 leading experts in reproductive biology, microbiome science, and immunology from around the world.
UCC(University College Cork in Ireland) researchers published such findings on January 25th 2023 in the prestigious journal of Nature.
Microbes don’t surround foetuses in the pregnancy
But, a recent review that coauthored with a global team of 45 other specialists and was published in Nature revealed no solid support for such a microbiome.
This topic has given rise to a whole field of study that extends beyond describing alleged microbial populations in the womb to speculating on their possible medicinal significance. Research on this has cost tens of millions of dollars, and hundreds of publications have been published.
However, not all scientists have been as enthusiastic. Early on, opponents said that the knowledge of human biology precluded the possibility of a prenatal microbiome.
For instance, UCC teams are aware of the several anatomical and immunological barriers present in the placenta that prevent bacteria from penetrating and colonising it.
The team knows that the growing immune system of the foetus would be unable to keep the bacteria under control.
A growing number of studies that demonstrated that the microbial DNA found in the placenta and amniotic fluid was caused by the contamination of the samples, research tools, and reagents(= chemical components) used to separate the DNA from the samples justified scepticism.
There was a spirited scientific discussion that featured opinions that couldn’t really be reconciled. The debate came to a head when four studies using direct DNA sequencing to study the bacteria in the human foetus reached diametrically opposed findings and were published in reputable scientific publications in 2020 and 2021.
In the intestines and other organs of vaginally delivered foetuses, two researchers discovered viable microbial colonies and connected these microorganisms to immune system development. The other two sated that there were no microorganisms present.
Such doubts on a basic question, for instance, by directing limited resources into research that yields little gain of the health of newborns and their mothers, constitute a significant obstacle for scientific development.
The possibility of medically altering hypothetical microbiomes exists as well.
The team’s experts examined the facts and all facets of the conflicting data to settle the argument. We tried to tackle the issue in several ways given the debate.
In particular, reproductive biology, microbiology, data science, immunology, clinical microbiology, and gnotobiology(= the study of germ-free plants and animals).
More than half of the scientists engaged had no prior engagement in the discussion since we wanted a fair approach.
The committee unanimously rejected the idea of a foetal microbiome and came to the conclusion that any microorganisms found in foetal tissues were caused by contaminated womb samples, chemicals, or research equipment.
The large contamination occurred during vaginal sampling, according to a thorough study of the bacterial populations found in foetuses delivered vaginally vs by caesarean surgery.
Healthy foetal tissues are germ free
The specialists came to the further conclusion that the presence of living bacteria in healthy foetal tissues was incompatible with the basic ideas of immunology, clinical microbiology, reproductive biology and the capacity to create germ-free animals.
COC researchers are confident that the agreement reached by the specialists we gathered would serve as direction for further investigation. By doing so, a strong scientific basis is created for focusing research efforts where they will be most beneficial.
It’s still crucial to understand how the developing foetus’ immune system functions. The focus is shifted from living bacteria to the parts of germs’ cells and the substances metabolites they create when it is known that the foetus is sterile.
Such substances have been demonstrated to pass the placenta and strengthen the foetus’ immune system in order to survive in a germ-filled environment.
The most recent study makes it clear that microorganisms colonies newborns both during and after delivery. Therefore, the time following birth should be the main focus of efforts to modify microbiomes to enhance baby and lifetime health.
Source: news medical
