Difucosyllacto-N-hexaose (a), a human milk oligosaccharide (HMO) found in breast milk, plays a key role in infant immune development and gut microbiota modulation. It is primarily utilized in the field of glycobiology and biomedical research, serving as a crucial component in studying cell-cell interactions and immune responses due to its role as a complex carbohydrate. This compound is often employed in the development of diagnostic tools and therapeutic agents, particularly in cancer research, where it helps in understanding tumor progression and metastasis. Additionally, it is used in the production of specialized glycoconjugates for vaccine development, enhancing the immune system's ability to recognize and combat pathogens. Its application also extends to the study of gut microbiota, exploring the relationship between dietary glycans and microbial colonization, as well as infectious diseases and inflammation.