Health Outcomes in C-Section Infants With Fecal Microbiota Transplantation

This single-center randomized controlled trial evaluates whether donor-derived fecal microbiota transplantation (FMT) administered within 6 hours after birth can improve gut microbiota development and reduce the risk of immune-mediated and metabolic diseases in infants born by elective cesarean delivery. Newborns are randomized 1:1 to receive either donor-derived FMT or standard postnatal care. Participants are followed through 36 months of age with stool samples, questionnaires, growth assessments, and health data collection, with registry-based follow-up continuing until 10 years of age.

Inclusion Criteria: Pregnant women aged 18 to 49 years Scheduled for elective cesarean delivery at term (≥37 completed weeks of gestation) Willing and able to provide written informed consent Infant eligible for study participation following birth Exclusion Criteria (Mother): Age \49 years Multiple pregnancy Regular use of immunosuppressive biological medication Diagnosed immunodeficiency in the mother Diagnosed immunodeficiency in a first-degree relative of the unborn child Known or suspected major congenital structural anomaly in the fetus Known or suspected fetal immunodeficiency Previous participation in the SISU-FMT study Exclusion Criteria (Infant): Preterm birth (\