The new data, published in the Journal of Proteome Research, suggests that babied fed on formula, rather than breast milk, experience metabolic stress that play a role in long-recognised links between formula-feeding and an increased risk of obesity, type 2 diabetes and other conditions in adult life.
Led by Dr Carolyn Slupsky from the University of California, Davis, USA, the research team used an infant rhesus monkey model to comprehensively compare the metabolic implications of formula- and breast-feeding practices by measuring urinary and blood metabolites in addition to sampling cytokines and fecal microbial profiles.
"We show that formula-fed infants are larger than their breast-fed counterparts and have a different gut microbiome that includes higher levels of bacteria from the Ruminococcus genus and lower levels of bacteria from the Lactobacillus genus," explained Slupsky and her colleagues - adding that the formula-fed infants also had higher serum insulin coupled with higher amino acid levels, while amino acid degradation products were higher in breast-fed infants.
"Our findings support the contention that infant feeding practice profoundly influences metabolism in developing infants and may be the link between early feeding and the development of metabolic disease later in life," they suggested.
Slupsky and her colleagues used the rhesus monkey model to compare the comprehensive metabolic implications of formula- and breast-feeding practices using NMR spectroscopy to characterize metabolite fingerprints from urine and serum, in combination with anthropometric measurements, fecal microbial profiling, and cytokine measurements.
They found that the infant monkeys fed formula were larger, and had different microbiota make-up to their counterparts fed breast milk.
Indeed, they noted that the formula fed monkeys had higher levels of bacteria from the Ruminococcus genus and lower levels of bacteria from the Lactobacillus genus in their gut.
Additionally, the formula-fed infants were found to have higher serum insulin, coupled with higher amino acid levels - while amino acid degradation products were higher in breast-fed infants.
Slupsky and her team also observed increases in serum and urine galactose and urine galactitol in the second month of life in formula-fed infants - along with higher levels of immune factors including TNF-alpha, IFN-gamma, IL-1-beta, IL-4, and other cytokines and growth factors at week 4.
“These results demonstrate that metabolic and gut microbiome development of formula-fed infants is different from breast-fed infants and that the choice of infant feeding may hold future health consequences,” said Slumpsky and her colleageus.
Source: Journal of Proteome Research
Volume 12, Issue 6, Pages 2833–2845 doi: 10.1021/pr4001702
"Early Diet Impacts Infant Rhesus Gut Microbiome, Immunity, and Metabolism"
Authors: Aifric O’Sullivan, Xuan He, Elizabeth M. S. McNiven, et al