infant microbiome


A study has found that delivery method during birth, and feeding during the early weeks of life significantly impact upon the make-up of the infant microbiome.


An array of recent research has highlighted the importance of the gut microbiome in human health. A recent study has also assessed the role of mode of birth and infant feeding method in the development of the infant intestinal microbiome.

The research study followed 102 infants from birth until 6 weeks of age, at which point microbiome composition was determined using a stool sample. The results of the study revealed that the composition of the infant microbiome was significantly different between infants born via caesarean versus vaginal delivery. While the mode of delivery more significantly impacted on microbiome composition than did feeding method, there was also an association found between infant microbiome and feeding method. This result was particularly interesting, since not only did the study assess breastfeeding versus formula feeding, but also a combination of the two. The make-up of the infant microbiome was significantly different between infants who were exclusively formula-fed versus exclusively breastfed. Additionally, the researchers found that in infants who were both formula and breastfed, microbial composition resembled that of exclusive formula feeding more closely than exclusive breastfeeding.

The researchers conclude that microbiome composition is significantly associated with both delivery methods and feeding method at 6-weeks of age. Importantly, supplementing breastfeeding with formula feeding (which is a common practice), results in a microbiome similar to infants who were exclusively formula-fed.

These results could have important implications for decision-making in terms of both delivery method and infant feeding, and support the World Health Organization’s ‘Baby Friendly Hospital Initiative’. This initiative promotes exclusive breastfeeding from birth, without supplementing with formula feeding, except in cases of medical necessity.




Madan, JC, Hoen, AG, Lundgren, SN, Farzan, SF, Cottingham, KL, Morrison, HG, Sogin, ML, Li, H, Moore, JH, Karagas, MR. “Association of Cesarean Delivery and Formula Supplementation With the Intestinal Microbiome of 6-Week-Old Infants” JAMA Pediatr. Published online January 11, 2016.


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Written by Deborah Tallarigo, PhD

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