by Bianca Garilli, ND
The Global Breastfeeding Collective (GBC), co-led by UNICEF and WHO, has a mission to rally political, legal, financial, and public support for breastfeeding, which will benefit mothers, children, and society. Seven key priorities have been set forth by the GBC to increase the rate of breastfeeding globally; their most recent data from 2017 evaluated 194 nations and found that, “only 40 percent of children younger than six months are breastfed exclusively (given nothing but breastmilk) and only 23 countries have exclusive breastfeeding rates above 60 percent”.1 Looked at from the other side of the coin, this means a full 60% of children younger than six months are being partially to fully fed via breastmilk substitutes, typically in the form of infant formula.
When compared to breastfeeding, formula-feeding has been associated with a variety of negative effects in the infant/child including lower intelligence, atopy, type 1 and type 2 diabetes, and childhood obesity.2-4 Studies have indicated that the presence vs. absence of breastfeeding has a significant impact on the critical early development period, with more recent evidence demonstrating that the breastfeeding vs. formula health outcomes may be mediated in part by differential effects on the composition of the gut microbiome.4-5
To better understand the relationship between breastfeeding, the microbiota, and the risk of overweight during infancy, a study that included 1087 infants (507 girls; 580 boys) was carried out utilizing the prospective Canadian Healthy Infant Longitudinal Development (CHILD) pregnancy cohort.5 Feeding methods were reported by mothers and documented from hospital records, and fecal microbiota samples at time periods 3-4 months and/or 12 months were characterized by 16S ribosomal RNA sequencing.5 Risk for overweight was designated if the infants weight-for-length ratio exceeded the 85th percentile.5
At the 3-month mark, it was found that infants who were exclusively formula fed experienced:5
A subset of infants who were briefly supplemented with formula as neonates but were then subsequently, exclusively breastfed were found to have a lower relative abundance of Bifidobacteriaceae and higher relative abundance of Enterobacteriaceae at the 3-4 month timeframe.5 This short exposure to formula and change in microbiota composition was not found to influence their risk of overweight at 12 months.5
The 6-month time point represents a period when breastfeeding mothers may choose to supplement with formula and/or introduce foods to the infant. These feeding methods/practices at 6 months of age influenced the microbiota composition of the infant at 12 months in the following ways:5
Finally, the authors found that the infant gut microbiota profiles at 3 months were more strongly associated with overweight risk than the microbiota profiles at 12 months.5
Why is this Clinically Relevant?