Micro-organisms in the gut microbiome begin growing in foetuses as early as five months, new research shows.
In a study described in the journal Scientific Reports, a team led by Australia’s La Trobe University found hundreds of bacteria in the intestinal tract of calf embryos that help the baby develop before birth.
“Our findings confirm, without doubt, that bacteria colonise in the gut before birth, changing the future of foetal research and our understanding of how the microbiome influences our developing immune system, gut and brain,” says co-author Ashley Franks.
The gut microbiome is essential for our long-term health; it promotes better digestion, heart and brain health and protects us from illness and disease.
Previously, we thought the uterus was completely sterile and the microbiome was determined during or immediately after birth. Franks and colleague found that the makeup of the microbiome was determined well before birth, and that it helps the baby’s immune system and brain develop.
“We believe the reliability with which we observed the microbiome to develop shows gut microbiota are essential to foetal development,” says La Trobe’s Jennifer Wood.
The researchers identified DNA of hundreds of bacteria and other micro-organisms in calf foetuses using next-generation sequencing, and these were the same in every calf. This means that selection of micro-organism before birth was not random but was specific to helping the foetus develop.
In humans, the microbiome has a connection to brain and immune system development, too. This study provides evidence that brain health of children may also be determined by the developing gut microbiome before birth.
“Together, we are studying the connection between the nervous system and microbes in neurodevelopmental disorders such as autism,” says Wood.
This new way of understanding how the microbiome is made provides many new ways of studying the development of the immune system, autoimmune disorders, and autism.