Perspective: Human Milk Oligosaccharides: Fuel for Childhood Obesity Prevention?

Obesity begins early but has lifelong consequences for health and well-being. Breastfeeding is thought to be preventive against obesity, but the extent and cause of this association are not well understood. Human milk oligosaccharides (HMOs) are abundant in human milk and not present in commercially available infant formula. These complex sugars are thought to contribute to the development of the infant gut microbiome and immune system. Recently, they have been investigated as a potential link between breastfeeding and lower obesity risk. So far, only a few human studies have examined HMO composition of human milk in association with the infant's concurrent anthropometry or subsequent growth in infancy, with conflicting results. However, HMOs have been shown to modulate the gut microbiome profile by selectively promoting the growth of specific bacteria, such as bifidobacteria. Moreover, there are differences in the gut microbiome of lean and obese humans, and there is some evidence that the early composition of the gut microbiome can predict later obesity. Although it seems that HMOs might have a role in infant growth and adiposity, there is not enough consistent evidence to understand their potential role in obesity prevention. More data, particularly from large or longitudinal studies, are needed to clarify the functions of HMOs and other breast-milk components in determining long-term health.