Previous studies have suggested that babies are born sterile and their gut microbiota is established only by the bacteria in their environment.
The project “Research on transmission mechanism and correlation of mother-to-child microbiota” undertaken by Professor Zhang Heping of Inner Mongolia Agricultural University has been accepted by experts, and its research results have solved the transmission mechanism of mother-to-child microbiota, or will redefine and explain the origin of human intestinal microbiota.
Using a combination of third-generation sequencing and microdroplet digital PCR (polymerase chain reaction), the team studied the bacterial structure of 41 pairs of maternal and infant volunteers using samples of meconium, maternal faeces, amniotic fluid, fluid from the birth canal, breast milk and maternal saliva. The results showed that firmicutes and proteobacteria were the dominant phyla in meconium, amniotic fluid, birthing canal fluid and breast milk, while firmicutes and bacteroidetes were the dominant phyla in maternal feces and saliva.
Meconium and amniotic fluid, vaginal fluid, breast milk of flora similarity degree is significantly higher than with other mother source the similarity of the sample, it is indicated that the early infant gut bacteria living conditions of the structure and before delivery (amniotic fluid) and delivery process in the environment (the birth canal) is closely related to the structure of the flora, the fetus may be in the womb by swallowing amniotic fluid to obtain the original source of mother microorganisms.
In addition, the team found that the absolute levels of Lactobacillus in meconium in babies born naturally were significantly higher than in babies born by cesarean section. This suggests that different delivery modes affect the colonization of lactobacillus in the early intestinal tract of infants, which may be related to the transmission of bacteria in the natural delivery process when infants come into contact with the mother’s birth canal.
The research results of this project revealed and proved that the meconium microbiome of infants came from multiple maternal parts, among which the amniotic fluid microbiome contributed the most to the meconium microbiome, which provided an important reference for in-depth understanding of the origin of human intestinal microbiome.