PURPOSE OF REVIEW: Human milk is the optimal food choice for infants. Reviewing the latest advances in research about human milk compounds and their effect on health helps understand the benefits of breastfeeding and improves knowledge of key bioactive nutrients that can be used to improve feeding during infancy, with short and long-time effects on health. RECENT FINDINGS: In the last years, it has been described how bioactive compounds such as Human milk oligosaccharides, hormones, lipids, cellular components and microbes play an important role in the infants' health, reducing the risk of infectious, metabolic and autoimmune diseases. The mechanisms of transmission from the mother to the infant of these bioactive compounds are not always well described, but there are several lines of research to understand the biological mechanisms of these beneficial effects. SUMMARY: These findings may help improve research in maternal and infant interventions, the modifiable factors that are able to modulate human milk composition. They may help to improve the development of infant formulas and enhance nutritional plans. Also, human milk bioactive compounds identification and isolation may describe new ways of supplementation.