Transplantation of maternal faecal microbiota may safely correct gut microbiota imbalance in infants born via caesarean section (C-section), according to the results of the SECFLOR* trial.

Principal coordinate analysis on beta-diversity showed significant differences in intestinal microbiome between infants who received their mothers’ gut microbiota (intervention) and those who received placebo (control), reported one of the authors Dr Otto Helve from the Finnish Institute of Health and Welfare in Helsinki, Finland. [IDWeek 2024, abstract 381]

Group differences were observed as early as 2 days (group: 22 percent of variation explained; p=0.001) and persisted until 6 months of age (group: 9 percent of variation explained; p=0.025), Helve said.

Laboratory parameters of infants at 2 days of age indicated elevated C-reactive protein levels in one infant in the intervention group and in three in the control group (14, 5, 6, and 11 mg/L, respectively). The infant in the intervention group had bilateral grade 1 intracranial haemorrhage.

Additionally, one infant in the intervention group was treated for transient tachypnoea of the newborn after receiving the transplant. One infant in the control group was hospitalized at 5 weeks of age due to vomiting and crying.

“None of the adverse events were considered related to the transplant,” Helve noted.

SECFLOR

“Normal microbial colonization process from the mother to the newborn is disrupted by birth by C-section” due the lack of exposure to the maternal vaginal microbiome during birth, according to Helve.

SECFLOR is first randomized, double-blind trial to demonstrate successful modulation of neonatal gut microbiota by maternal faecal microbiota transplantation, he added. “Analyses focusing on immunodevelopment are underway.”

For SECFLOR, Helve and colleagues recruited 90 healthy pregnant women scheduled for C-section.All of the women were asymptomatic (ie, no diarrhoea or abnormal bowel functions), and none had been prescribed antibiotics or travelled outside of Europe in the 3 months prior to screening.

A total of 54 women and five infants were excluded from the trial. Most of these women (n=38) tested positive for potentially harmful pathogens, including Group B Streptococcus, Dientamoeba fragilis, and Helicobacter pylori. Of the infants, four had transient tachypnoea and one had a birthweight of <2.5 kg.

Thirty-one mother?infant pairs participated in the trial, with the infants randomly assigned to receive 3.5 milligrams of screened maternal faecal microbiota (n=15) or placebo (n=16) mixed in mother’s milk. The infants were followed for up to 24 months.

Stool and blood samples from the infant and mother were collected at prespecified timepoints throughout the follow-up and were analysed for changes in microbiome heterogeneity.