Advantages and methods of microbial seeding following cesarean birth examined

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Eden Fromberg, DO

Initial excitement about vaginal microbial seeding of cesarean-born babies to bolster their microbiome and future health is under scrutiny, due to the uncertainty of benefits and potential for risk.

“While it is important to educate parents interested in pursuing microbial or vaginal seeding, more recent reviews of the literature point to antibiotics as being a primary driver of microbiome compromise,” said Eden Fromberg, DO, founder and director of Holistic Gynecology New York, in Manhattan. “We now know that the vaginal, placental and fecal microbiomes, and breastfeeding, also contribute to the neonatal microbiome.”

Overall, there appears to be several mechanisms at play for the acquisition of the microbiome at birth, and beyond. “We need to be considering diverse opportunities to enrich the microbiome for the baby, and mitigate microbial compromise from cesarean delivery,” said Dr. Fromberg, who spoke on microbial seeding and its influences on fetal microbial colonization and immune development at the 2019 ACOG annual clinical and scientific meeting in Nashville.

Previously, several studies concluded that cesarean-born babies have a higher incidence of allergies, developmental challenges and autoimmune diseases later in life. “Even a single course of perinatal antibiotics has been demonstrated to trigger these types of illnesses,” Dr. Fromberg told Contemporary OB/GYN.

The 2014 documentary film “MicroBirth” illuminated the microbial seeding research done by microbiologist Maria Gloria Dominquez-Bello of New York University Langone Medical Center. “These studies indicated that microbial seeding could restore some of the observed microbiological shifts seen in cesarean born infants,” Dr. Fromberg said. “The technique involves swabbing the newborn’s face, orifices and skin with a gauze that had been placed in the mother’s vagina before delivery, to absorb her secretions and associated microbiome.”

But in those cesarean born babies who were not swabbed, their microbiome was acquired from skin cells in the operating room. These babies’ microbiomes were less diverse and more enriched with clostridia, including clostridium difficile (C. Diff.). 

Dr. Fromberg identifies C. Diff. as a “superbug” that causes life-threatening hemorrhagic diarrhea when it overpowers a gut microbiome damaged by antibiotics. “Its increasing prevalence in hospital and neonatal environments is predicted to contribute to overall mortality in numbers exceeding that of heart disease or cancer by midcentury,” she said.

Based on initial research, a number of parents became interested in microbial seeding and began to demand the procedure. “The obstetrical response to this grassroots movement has been to express concerns about communicable diseases, including Group B strep, which could be introduced by the technique,” Dr. Fromberg said.

As to whether microbial seeding “works” is complex and cannot simply be answered, according to Dr. Fromberg. “Microbiomes involve diverse communities of organisms,” she said. “Microbial seeding is like introducing well-behaved children into a classroom of unruly kids in the hopes that they will have a positive influence on the behavior of the whole. Will they make friends? Will they get beaten up? Will they transfer out? Will they take on the qualities of the unruly kids, or vice versa? Will they destroy the classroom? These are the sorts of questions that research is attempting to answer.”

In addition, because there are various microbiomes in the body, whether seeding is executed with vaginal or fecal material would influence methodology and outcomes. “There are multiple variables and levels of complexity involved, demanding that clinical research assess not just isolated factors but dynamic function and short- and long-term outcomes,” Dr. Fromberg said.

“While microbial seeding offers true promise, it also offers true risk, requiring an expanded spectrum of carefully focused research design and methodology, to further assess safety, efficacy, risk, relevance, and short- and long-term outcomes,” Dr. Fromberg said. “This is why, with what is known about the long-term health consequences of cesarean delivery, it becomes important to take another step back as a profession toward valuing and facilitating vaginal delivery and breastfeeding, both of which continue to prove themselves to be the most cost-effective routes to realizing short- and long-term health benefits for newborns and for a lifetime.”

Concerning fecal microbiota transplantation (FMT), the colonoscopic or oral introduction of healthy donor fecal material by FMT has been demonstrated to restoratively treat the very diseases in which microbiome compromise is implicated, according to Dr. Fromberg. “In contrast to the aseptic conditions necessary for cesarean delivery, the proximity of stool often passed during vaginal delivery may represent a form of spontaneous seeding,” she said. “Studies of FMT in newborns and children are already underway.”

Dr. Fromberg advocates advancing obstetrical culture to embrace vaginal birth and breastfeeding, while considering diverse ways to positively influence and restore the microbiome at the time of birth and in subsequent neonatal life.