Human milk oligosaccharides (HMOs) are a group of complex carbohydrates that are highly abundant in human milk and contribute to shaping the infant’s gut microbiome and immune system for immediate and long-term health benefits. HMOs are the 3rd largest solid component of human milk and over 200 HMOs have been identified so far. 2’FL and LNnT are among the most studied HMOs with clinical evidence to support immunity and the developing microbiome, but latest research on additional HMOs show promise in expanded benefits on gut, immune, brain and bone health.