The maternal contribution to the composition of the newborn’s microbiota is widely documented, but a new study has now revealed the significant paternal influence on the microorganisms that colonize the intestine of a baby, and also confirms that maternal fecal microbiota transfer (FMT , for its acronym in English) in babies born by cesarean section can correct the microbial alterations common in these newborns.
The research is the result of the work of an international team of researchers from the Universities of Wageningen, Helsinki and Trento, in collaboration with the Pompeu Fabra University, the Helsinki University Hospital, the Finnish Institute of Health and Welfare, and the European Institute of Oncology IRCCS.
Fetuses possess sterile gastrointestinal tracts and babies’ bodies are colonized during and shortly after birth. Approximately half of the microbial strains in babies come from the mother’s intestine. This observation led the researchers to hypothesize that other people close to the baby could contribute to the rest, providing beneficial microbial strains for health.
“This study provides crucial data on how a newborn is colonized,” said Willem M. de Vos, lead author and co-author of the study, from Wageningen University and the University of Helsinki. “Although the father’s contribution may seem small, it should not be underestimated. It is likely that close people also play an important role in this colonization.”
“We are very pleased to have identified this connection,” adds Nicola Segata, co-author of the study, from the University of Trento. “This highlights the importance of investigating other sources of microbiota, such as siblings and daycare peers.” Segata’s team was responsible for the computational analysis, while de Vos’ team designed the study.
“Last year we showed that there is widespread transmission of the microbiome between adults with close social contact. Now, we confirm that this also occurs in newborns: they receive their first microbiota from their mothers, but close individuals, such as fathers, complement this contribution. This is crucial for babies born by cesarean section,” adds Mireia Vallès-Colomer, researcher at Pompeu Fabra University and co-first author of the study, whose findings have been published in Cell Host & Microbe.
Improve the intestinal microbiota in babies born by cesarean section
Parent-child interaction is essential to complete the neonatal microbiome. Inspired by his experience as a father, de Vos has for years studied the microbiota of babies and how their gastrointestinal tract is colonized after birth. In October 2020, he and his team published an earlier study in Cell that confirmed that exposing C-section newborns to maternal microbiota after birth is safe and effective in giving babies a microbial composition similar to that of those born vaginally. The babies received a small amount of fecal microbiota from their mothers shortly after birth.
This new study provides follow-up data to that research, as well as new findings about the paternal contribution to babies’ microbiota. The authors note that with cesarean deliveries accounting for a quarter of births worldwide, it is important to pay more attention to creating a healthy balance of gut microbiota in these babies.
The researchers carried out metagenomic analyzes of fecal samples from newborns and their parents, looking for a wide variety of bacterial strains over time. In the case of the babies in the previous study, they confirmed that maternal FMT significantly reduced the levels of potentially pathogenic strains up to a year later.
“Knowing that the father contributes substantially to the baby’s developing microbiome underscores the importance of physical and social interactions between the newborn and his father, as well as with other family members.”
In this recent study, the fecal microbiomes of babies born by cesarean section (21) and vaginally (52) were compared, with samples taken over a year, along with those of their mothers and fathers. They found that many strains found in 3-week-old, 3-month-old, and 12-month-old babies came from the father, not the mother. Among them, Bifidobacterium longum was identified, which uses oligosaccharides from breast milk, although it may come from the father.
“Knowing that the father contributes substantially to the baby’s developing microbiome underscores the importance of physical and social interactions between the newborn and his father, as well as with other family members,” says Segata. “We hope this study will raise awareness of these important contributions.”
In statements to SMC Spain Toni Gabaldón, ICREA Research Professor and head of the Comparative Genomics group at the Institute for Biomedical Research (IRB Barcelona) and the Barcelona Supercomputing Center (BSC-CNS), who has not participated in this study, states that “ yields interesting results, such as a relevant role of fathers that is later and initially more modest than that of mothers, but that equalizes quantitatively when the boy or girl is one year old. It is observed that mother and father contribute different species to the infant’s microbiota and, therefore, could be complementary. Perhaps expectedly, the use of antibiotics before or during childbirth has a clear impact on the infant microbiota, but manages to reduce the abundance of pathogens. Similarly, fecal transplantation also reduces the presence of opportunistic pathogenic species. However, in cesarean births it is not possible to restore a microbiota similar to that of a vaginal birth, but rather a different one, rich in species and poor in pathogens, but different.”
“Given the limitation of the sample size, the observations should be corroborated in other studies, but they point to possible ways of restoring a natural microbiota in non-vaginal births and call for the need to study the effect of the use of different antibiotics during childbirth, which It was used in all cesarean deliveries in this study, but also in almost half of the vaginal deliveries. The role of parents in establishing babies’ microbiota is not surprising, but it raises questions about the health implications. Likewise, it would be interesting to study cases with other family configurations, such as single-parent or homo-parent families.”
“Traditionally, mothers have been assigned the role of inoculating babies, either through the vaginal microbiota during childbirth, through skin contact when breastfeeding, or through milk that contains bacteria from the mother’s intestine. It is a very good contribution to study the influence of the paternal microbiota, although it was known that family members also condition the final microbiota of the child, it is the first time that the father’s influence has been revealed. That, to a certain extent, equalizes the responsibility of both parents to provide the child with good bacteria,” adds Rosa del Campo Moreno, clinical researcher at the Ramón y Cajal Hospital, in statements to the same medium.
Source: Pompeu Fabra University
