代謝：母乳栄養で育てる期間を長くすることが齧歯類を成体期の肥満から守る

Rodent pups that are allowed to breastfeed for longer are less likely to become obese during adulthood, even when exposed to a high-fat diet, according to a paper published in Nature Metabolism. These findings provide evidence about the importance of breastfeeding in rodents, however, future research is needed to determine if these effects extend to other mammals, such as humans.

Maternal diet and newborn feeding are considered key early-life determinants of neurodevelopmental and behavioural responses that can influence lifelong metabolic health. Although the impact of maternal nutrition on offspring has been extensively studied, the mechanisms by which breastfeeding impacts energy balance over a lifetime remains largely unexplored.

Rubén Nogueiras and colleagues reveal how prolonged suckling can protect against diet-induced obesity later in life. The authors reveal that delayed weaning (from four weeks versus three weeks) protects rats from weight gain in adulthood, even if they are exposed to a fatty diet. This phenomenon can be explained, the authors state, by the release of a protein known as fibroblast growth factor 21 from the liver, which can reach the hypothalamus — a region in the brain that plays a key role in controlling energy consumption and utilization in the body. This in turn leads to increased mobilization and use of fat tissue, as well as increased energy expenditure.

These findings shed new mechanistic insight into the long-lasting benefits of breastfeeding in rodents, further supporting its protective role against metabolic diseases such as obesity in adulthood. In an associated News & Views, Elisa Félix-Soriano and Kristin Stanford highlight that this work “will surely lead to new research in developmental biology and pave the way for clinical studies to better understand the long term metabolic benefits of breastfeeding”.