Storage Conditions and Breast Milk Microbiota Composition

Breast milk is the mainstay of newborn nutrition, providing all the nutrients and vitamins necessary for optimal growth of newborn infants. Beside its nutritional properties, breast milk also contains bioactive factors such as soluble immune factors, antimicrobial proteins, functional fatty acids, hormones, oligosaccharides, stem cells and microbiota. Although fresh breast milk is the optimal source of nutrition for newborn infants, breast milk must be expressed and stored in some conditions.Breast milk was thought to be sterile for many years. This idea has changed with the isolation of live bacteria in the breast milk of healthy mothers in the recent past. Thus, it has been shown that breast milk is not actually a sterile body fluid, but has a microbiota of its own. This study aimed to examine the effect of storage conditions of breast milk at different temperatures on the microbial composition of the breast milk.The prospective experimental study will be conducted under the supervision of Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Neonatology Department. Informed consent of mothers will be taken. Thirty mililiter (30 mL) breast milk that was obtained from volunteer mothers will be divided into 3 samples, each 10 mL of breast milk will be stored at different temperatures. Ten mililiter will be studied for microbial composition with 16S rRNA amplicon sequencing and bioinformatics analysis immediately, 10 mL will be stored at +4'C for 3 days and will be studied at the end of 3rd day, other 10 mL will be stored at -20'C for 3 months and will be studied at the end of 3rd months. 16S rRNA amplicon sequencing and bioinformatic analysis studies will be performed at Istanbul Medical Faculty Clinical Nutrition and Microbiota Research Laboratory.This present study is planned to be carried out for 24 months between January 2023 and December 2024

Inclusion Criteria:Women who had vaginal deliveryWomen who gave delivery at gestational age above 37 weeksWomen who have a child older than 1 weeks of ageMothers with a body mass index between 18.5-25Women who gave consentExclusion Criteria:Women who had cesarean deliveryWomen who gave premature delivery (<37 weeks of gestation)Women who gave birth within prior 7 daysWomen with premature rupture of membranesWomen with chorioamnionitisWomen who had antibiotherapy within last 1 weekPresence of mastitisPresence of maternal co-morbid diseases such as; pregestational diabetes, pregestational hypertension, connective tissue diseases, inflammatory bowel syndrome, solid organ transplantationPresence of evidenced congenital infectionsWomen who didn't give consent