You Are What You Eat – Starting at Birth or Even Before!

The human gut microbiome is an area of active research and rapidly expanding knowledge with potentially significant implications for health and disease.  Yet, even though the field is relatively young, it is not without controversy.  Some studies have concluded that the mode of delivery at birth plays an important role in infant microbiome development.¹ Infants born vaginally have a gut microbiome that approximates that of their mother’s vaginal and fecal flora.  However, infants who are delivered by cesarean section tend to be colonized with bacteria resembling their mother’s skin flora.  Their intestinal microbiome exhibits less diversity – a finding that may be linked to human diseases like inflammatory bowel disease and obesity.²     

However, a recently published study by researchers at Baylor College of Medicine found no differences in the microbiome of infants at 4 to 6 weeks of age between those delivered by C-section or born vaginally. According to the researchers, one explanation is that the microbiome may actually have been established in utero from the placenta during pregnancy and even undergone some maturation prior to birth. ^3,4  

Infants who are breastfed after birth continue to exhibit colonization and maturation of their gut microbiome. According to a recent study from UCLA⁵, breast milk contributed more than 25% of the bacteria to the infant gut with an additional 10% coming from the areolar skin - findings that were most pronounced during the first month of life.  More importantly, infants who continued to breast feed through 6 months of age after the introduction of solid foods had a lower incidence of obesity and asthma.  Although these findings need to be corroborated, they potentially add to the body of evidence supporting the benefits of breast feeding.

 

Judith Wolf, MD

          Associate Director, WHEP

 

1. Yang I, Corwin EJ, Brennan PA, Jordan S, Murphy JR, Dunlop A. The Infant Microbiome: Implications for Infant Health and Neurocognitive Development. Nursing research. 2016;65(1):76-88. doi:10.1097/NNR.0000000000000133.
2. Mueller NT, Bakacs E, Combellick J, Grigoryan Z, Dominguez-Bello MG. The infant microbiome development: mom matters. Trends in molecular medicine. 2015;21(2):109-117. doi:10.1016/j.molmed.2014.12.002.
3. Derrick M Chu et al. Maturation of the infant microbiome community structure and function across multiple body sites and  
   in relation to mode of delivery, Nature Medicine (2017). DOI: 10.1038/nm.4272
4. K. Aagaard et al. The Placenta Harbors a Unique Microbiome, Science Translational Medicine (2014).
   DOI: 10.1126/scitranslmed.3008599
5. Pia S. Pannaraj, MD, MPH; Fan Li, PhD; Chiara Cerini, MD; et al.   JAMA Pediatr.  2017;171(7):647-654. doi:10.1001/jamapediatrics.2017.0378