Babies’ Microbiome Affected by Cesarean Section and Formula Feeding Interview with:
Annie Gatewood Hoen, PhD 
Assistant Professor of Epidemiology and of Biomedical Data Science and
Juliette Madan, MD, MS
Associate Professor of Pediatrics
The Geisel School of Medicine at Dartmouth
Dartmouth-Hitchcock Medical Center
Lebanon, NH 03756

Medical Research: What is the background for this study? What are the main findings?

Response: When newborns are delivered they begin the process of acquiring vast numbers of bacteria that are critical for healthy nutrition and for immune training for a lifetime of health. Diseases such as obesity, heart disease, colitis, autism, and even cancer risk is associated with particular patterns in the gut microbiota; interestingly breast milk exposure is associated with decreased risk of many of these diseases. The intestinal microbiome plays a critical role in development, and delivery mode (cesarean section versus vaginal delivery) and feeding method (breast milk vs. formula) are important determinants of microbiome patterns.  We observed the intestinal microbiome in 6 week old infants and how it relates to delivery type and feeding. We were particularly interested in examining patterns in the microbiome in infants who received combination feeding of both breast milk and formula, an area that has been understudied.

We prospectively studied 102 infants and, with gene sequencing of bacteria, identified important patterns in microbiome composition that differed greatly based upon delivery method and between feeding groups.  Babies who were combination fed (formula and breast milk) had an intestinal microbiome that was more similar to babies who were exclusively formula fed than breast fed babies. We identified individual bacteria that were differentially abundant between delivery mode and feeding groups.

Medical Research: What should clinicians and patients take away from your report?

Response: The benefits of breast milk and its associations with a multitude of health benefits, both for infants but for a lifetime, has been indisputable. What we haven’t understood particularly well is why this is. Understanding the role that breast milk feeding has on the intestinal microbiome, and understanding how patterns in the microbiome relate to health outcomes, begins to shed light on the possible mechanisms behind the health benefits of breast milk and other factors in infancy. Gathering information about the effects of formula supplementation for breast fed babies on the intestinal microbiome points to a potential role of donor breast milk in situations when supplementation of mother’s milk is necessary.  Understanding how Cesarean section relates to specific patterns in the microbiome in babies, and investigating interventions to restore the infant gut microbiome to mirror that of babies’ delivered vaginally, will be an important undertaking.

Medical Research: What recommendations do you have for future research as a result of this study?

Response: Future studies, as planned by our group and others, will investigate in large populations the relationship between exposures in newborn life, effects on patterns of the microbiome, and relationships with health outcomes, both short and long term.


[wysija_form id=”5″]

Annie Gatewood Hoen, PhD, & Juliette Madan, MD, MS (2016). Babies’ Microbiome Affected by Cesarean Section and Formula Feeding 

Last Updated on January 11, 2016 by Marie Benz MD FAAD