Human Milk as a Model for Next-Generation Infant Formula: Opportunities and Challenges.

Human milk (HM) is a dynamic biological system replete with functional components that support infant growth, development, and immune protection. HM is regarded as the optimal infant food; however, many infants rely on infant formula (IF) as their sole source of nutrition or as a supplement to HM. Although many ingredients have been added to IF over the past 30 y, it is not equivalent to HM in terms of composition or infant outcomes. Potential opportunities to improve IF composition include adding components extracted from the milk of other species, synthesized by precision fermentation, or produced by cultured mammary epithelial cells. However, many hurdles remain to adding novel ingredients to IF, including determining how much to add to best align with variable HM composition, ensuring reasonable certainty of no harm, considering possible functional effects of the ingredients, establishing methods to assess the safety of the IF when the functional ingredient is added, and determining how best to assess functional outcomes. Advancing the field to improve infant health hinges on achieving consensus across a range of questions among academic, industry, and regulatory scientists.