Background: Human milk oligosaccharide (HMO) is a third most abundant component in
breast milk. HMOs are molecules naturally tailored to the need of an infant. They protect infants from
diseases, foster healthy gastrointestinal systems, reinforce fledgling immune function, and promote early
brain development. Supplement HMOs to infant formula, which lack this critical element, would substantially
improve the function of formula. Overwhelming evidence also indicate that HMOs can be
used for the treatment of arthritis and related autoimmune disease, and inhibition of bacteria adhesion or
as potential prebiotics. The prospect of using HMO in these applications has stimulated worldwide interest
in developing synthesis technology for these valuable products.
Methods: As the quantities extracted from human milk are limited, and chemical synthesis methods are
time-consuming, costly, and complex, biotechnological approach, involving either enzyme catalysis or
metabolically engineered bacteria is preferred. In this review, we highlight the most recent advances in
the synthesis technologies, as disclosed in patents and patent applications, and analyze these technologies
against those reported in literatures.
Conclusion: Significant progress has been made over the past decade, especially in whole-cell biocatalysis
for smaller HMOs. Significant challenges remain for larger and more complex HMOs.