Infant feeding method influences baby’s gut bacteria, risk of overweight

New findings from AllerGen’s CHILD Study indicate that exclusive breastfeeding in early infancy protects babies from becoming overweight by age one.

The study involved 1,087 Canadian mothers and infants participating in the CHILD Study and found a 63% increased risk of overweight among partially breastfed infants, and a 102% increased risk among exclusively formula-fed infants. The researchers believe that these differences relate to the effect of feeding practices on the infant gut microbiome—the community of microorganisms or bacteria that live in the human digestive tract.

With formula feeding, “more types of microbes were present in the baby’s gut, as well as an abundance of a group of bacteria called Lachnospiracae, which has been associated with infant overweight,” notes study co-author Dr. Anita Kozyrskyj, Faculty of Medicine & Dentistry, University of Alberta.

The study, published June 4, 2018, in JAMA Pediatrics, is one of the largest infant microbiome studies in the world, identifying over 900 types of bacteria from 2.6 million DNA sequences generated from more than 1,000 infants.

The study is unique in that it also distinguished between partial breastfeeding mixed with formula versus partial breastfeeding mixed with foods, and is the first to evaluate the potential association of a brief use of infant formula (during the hospital stay only) with infant microbiota and the risk of becoming overweight.

Drs Meghan Azad and Jessica Forbes from the University of Manitoba were co-first authors on the paper. Drs James Scott, University of Toronto, and Anita Kozyrskyj were co-senior authors.

Press release