Feeding the Preterm Gut Microbiota - Impact of Infant-feeding on Preterm Gut Microbiota Development

Feeding the Preterm Gut Microbiota - Impact of Infant-feeding on Preterm Gut Microbiota Development

Preterm infants are especially vulnerable to gut microbiota disruption and dysbiosis since their early gut microbiota is less abundant and diverse. Several factors may influence infants' microbiota such as mother's diet, mode of delivery, antibiotic exposure and type of feeding. The main goal of this observational study is to evaluate the impact of different types of feeding (breast milk, donor human milk and preterm formulas) on the intestinal microbiota of preterm infants hospitalized in the neonatal intensive care unit (NICU) of Maternidade Alfredo da Costa (MAC). Furthermore, the influence of mode of delivery and the mother's diet, among others factors, on vertical microbiota transmission will be evaluated. After delivery, mothers will be asked to collect their own fecal samples and will be invited to complete a semi-quantitative food frequency questionnaire. Stool samples will be collected from premature infants every 7 days. DNA will be extracted from fecal samples and different bacterial genus and species will be analyzed.

Meconium and the additional 3 fecal samples will be collected from preterm infants by the nursing team of MAC Neonatology Unit. Fecal samples will be collected every 7 days, during 21 days, from diapers into sterile tubes. Mothers will be asked to collect their own fecal samples with an appropriate stool collection kit (EasySampler®) and will be invited to complete a semi-quantitative food frequency questionnaire, previously validated for the Portuguese population.

Infant-feeding profile (breast milk, donor human milk or formula) of preterm infants will be recorded every day to select the most representative (>50 %) type of infant-feeding received during the 7 days prior to each fecal sample collection.

Additionally, detailed clinical data will be collected during the preterm infant enrollment in the study. Personal clinical data includes sociodemographic information and clinical intrapartum and postpartum outcomes, such as newborn's weight, days of antibiotic exposure, number of total days of hospitalization and others outcomes related to the preterm clinical evolution.

Inclusion Criteria:

• To be eligible for enrolment, preterm infants must have been admitted to the NICU in less than 24 hours of life, have been born with less than 32 weeks with absence of malformations or metabolic diseases.

Exclusion Criteria:

• non applicable