Fecal transplants for babies born by cesarean section may contain harmful pathogens

Key takeaways:

• A study testing fecal transplantation for babies born by cesarean section found that 42% of mothers carried potentially harmful pathogens.
• The most identified pathogen was group B Streptococcus.

More than 40% of healthy mothers recruited for a study testing fecal transplantation for babies born by cesarean section tested positive for potentially harmful pathogens, Finnish researchers reported.

The study, presented at the European Congress of Clinical Microbiology & Infectious Diseases, is the latest to examine fecal transplant therapy, which has been shown to prevent recurrent Clostridioides difficile infection in adults. The FDA in December approved a fecal microbiota product for the first time to treat recurrent C. difficile.

In their abstract, Otto Helve, MD, PhD, a pediatric infectious disease specialist at Helsinki University Hospital and director of the department of health security at the Finnish institute for Health and Welfare, and colleagues explained that delivery by cesarean section disrupts the normal vertical transmission of a birth parent’s beneficial gut bacteria to their baby, potentially raising their risk for immune-related diseases.

“Healthy people typically carry low levels of harmful bacteria in and on their bodies,” Helve said in a press release. “But when a person is healthy, these pathogens don’t cause disease; they simply coexist in an abundance of beneficial microbes. However, some, like group B Streptococcus, can cause life-threatening infection in the newborn.”

Beginning in 2019, Helve and colleagues recruited 90 mothers who opted for elective cesarean section for a double-blinded, randomized, controlled trial.

Within 2 hours of delivery, the researchers gave newborns either 3.5 mg of fecal microbiota transplant from their own mothers or a placebo mixed in their mother’s milk. They followed the children for 24 months, collecting stool and blood samples from children and mothers to analyze for changes.

Of the mothers, 38 (around 42%) were found to have harmful pathogens in their own sample upon screening, with group B Streptococcus detected in 14 samples, the parasite Dientamoeba fragilis in 11 samples, and the bacteria Helicobacter pylori in five samples.

Helve and colleagues reported that 31 infants received a transplant or placebo “without any noticeable side effects.”

“The high rate of significant pathogens found in healthy mothers underscores that this procedure should be only performed after careful screening for potential pathogens,” Helve said.

“In May 2023 we will begin assessing whether FMT can enrich the gut microbiota of C-section babies to match that of those vaginally born,” Helve said.

References:

Over 40% of healthy moms preparing for fecal transplant to C-section babies found to carry potentially harmful pathogens. https://medicalxpress.com/news/2023-04-healthy-moms-fecal-transplant-c-section.html. Published April 13, 2023. Accessed April 24, 2023.