• Obesity link
• Broad implications
What is already known on this topic
During pregnancy and early infancy, factors such as the nutritional status of mothers can influence the health of newborns. For example, children who grow unusually fast during the first few months of life have an increased risk of developing obesity and other metabolic diseases later in life — likely because metabolites such as choline and folate, which are found in breast milk, can affect infant growth.What this research adds
By analyzing 143 pairs of mothers and infants, researchers have found that a molecule in breast milk may help to reduce the risk of obesity by preventing accelerated growth in newborns and supporting certain bacterial species in the gut microbiota. When give to female mice, the molecule — called betaine — improved blood sugar metabolism and lowered fat tissue in breastfeeding offspring. Mouse pups and human infants fed with breast milk rich in betaine had higher amounts of beneficial bacteria such as Akkermansia in their guts.Conclusion
The findings show a link between breast milk betaine and long-term metabolic health of newborns, suggesting that the metabolite content in artificial milk may benefit formula-fed infants, who show a higher risk of accelerated growth in early life.
Breastfeeding has been linked to a score of health benefits for newborns, including fewer infections and a reduced risk of obesity. Now, researchers have found that a molecule in breast milk may lower the risk of obesity by preventing accelerated growth in newborns and supporting certain bacterial species in the gut microbiota.
The findings, published in Science Translational Medicine, suggest that the metabolites content in artificial milk may benefit formula-fed infants, who show a higher risk of accelerated growth in early life.
The health of newborns can be influenced by several factors, including the nutritional status of mothers during pregnancy and breastfeeding. For example, children who grow unusually fast during the first few months of life have a higher risk of developing obesity and other metabolic diseases later in life. That’s likely because metabolites such as choline and folate, which are found in breast milk, can affect infant growth, the researchers say.
Carles Lerin at Institut de Recerca Sant Joan de Déu and his colleagues studied a milk metabolite called betaine in 143 pairs of mothers and infants. One group of 34 mother-infant pairs was based in the US; a second cohort of 109 mother-infant pairs was based in the Spanish-Mediterranean area. All mothers were exclusively breastfeeding.
Obesity link
Betaine is naturally present in the diet and can also be metabolized from choline. The researchers found that infants fed with breast milk rich in betaine showed reduced growth rates after birth. Experiments in mice showed that giving betaine to female mice improved blood sugar metabolism and lowered fat tissue in breastfeeding offspring.
When breast-fed with milk rich in betaine, both mouse pups and human infants had higher amounts of Akkermansia bacteria in their guts. To test whether exposure to Akkermansia during early life could reproduce the effects of being fed with breast milk rich in betaine, the researchers administered A. muciniphila to pups in a mouse model of maternal obesity.
Administering A. muciniphila to pups resulted in a 10% decrease in weight gain compared to a control group. Twenty-week-old mice given A. muciniphila showed reduced weight as well as improved glucose tolerance and fasting insulin concentrations compared to control mice.
Broad implications
Previous studies have shown that low levels of maternal betaine during pregnancy are linked to increased infant weight at birth, whereas maternal betaine supplementation resulted in lower fetal weight in a mouse study. “Together with our results on human breast milk, these data support a link between lower maternal betaine status during pregnancy and breastfeeding and increased fetal and postnatal growth,” the researchers say.
The findings suggest that low milk betaine levels are associated with higher infant growth during the first months of life, and thus link milk betaine content and childhood obesity risk.
“The implications of this study might go beyond breastfeeding, as formula-fed infants are at higher risk of accelerated early growth and childhood obesity,” the authors say. The study also suggests that modulating betaine intake during the breastfeeding period could be used as a strategy to prevent childhood obesity, the authors say.
