TORONTO -- A new study suggests that feeding caesarean section newborns a small amount of their mother's feces, diluted in breast milk, just after birth may help to increase their exposure to healthy microbiota, commonly known as gut flora.
The small study, conducted by researchers in Finland, reported that the "proof-of-concept procedure" appears to be safe and after three months, resulted in the newborns having a microbial makeup that looks more similar to babies born vaginally than to those via C-section.
According to the study, infants delivered by C-section have an increased risk of developing asthma and allergies as babies and toddlers since they are not exposed to the microbiota in the mother's vagina and perineum during birth. Researchers say this negatively affects how the newborn’s immune system develops.
While previous studies have looked at whether swabbing a newborn's skin with vaginal fluid immediately after birth reduces this risk, researchers say feeding the newborn their mother's feces is a more drastic way to expose them to microbiota.
The Thursday in the journal Cell.
The study explained that a baby's immune system is undeveloped at birth and matures in response to microbial exposure once it begins living in the outside world.
"From a clinical point of view, this transfer of microbial material is happening during a vaginal delivery. This is a gift the mother gives to her baby," co-senior author Sture Andersson of the Pediatric Research Center at the University of Helsinki said in a press release.
While everyone’s microbiota is individualized, the study reported that the overall patterns of which bacteria types colonize the gut are different in babies born vaginally and those born by C-section. Researchers say these variations appear to make a difference in how the immune system learns to respond to outside stimuli, including potential allergens.
According to researchers, the seven mothers who participated in this study were recruited with leaflets placed in doctors' waiting rooms. Their babies were given the fecal microbiota transplants (FMTs) orally in breast milk shortly after birth, while the mother’s fecal samples were collected three weeks prior.
The study reported that the newborns stayed in the hospital for two days after the transplant to make sure there were no complications. The babies' own fecal microbiota was tested at birth and again after two days, one week, two weeks, three weeks, and three months. The babies also had blood work done two days after birth.
Researchers found that by three months of age, the microbiotas of the babies who received the oral FMTs were similar to those of babies born vaginally. The study reported that the newborns' microbiota was different from those of babies born by C-section without FMTs, as well as from their mothers' microbiota. The researchers used previously collected data at the same hospital, as well as global datasets for this comparison.
In their future work, researchers say they plan to further study the development of the immune systems in C-section babies who receive FMTs and compare it to those who don't. Unlike the current study, which was observational, future studies will have a control group and will be blinded to the mothers.
Despite how unpalatable the research may seem to most people, Andersson said the mothers who agreed to participate in the study were "very motivated."
She explained that one woman studied who was having twins was told the oral FMT could be given to one baby, with the other one used as a controlled subject. She declined, stating that she didn't want one of her babies to have "an unfair advantage" by receiving the transplant.
While the small study seemed to improve the microbiota of C-section newborns, co-senior author Willem de Vos of the University of Helsinki's Human Microbiome Research Program warns that new mothers should not try this at home.
"This was not designed as a safety study, but we found it to be effective and supporting the concept of vertical transfer from mother to baby. However, it's very important to tell people that this is not something they should try on their own. The samples have to be tested for safety and suitability," de Vos said in the release.
