From Bifidus Factor to Human Milk Oligosaccharides: A Historical Perspective on Complex Sugars in Milk

The discovery of Lactobacilli and Bifidobacteria and their relevance for health and disease was an important milestone leading to a decrease in infant mortality during the first year of life. At the same time, pediatricians realized that the composition of feces of breastfed and bottle-fed infants differ from each other. Observations indicated that this difference was linked to milk carbohydrates. Around 1930, a human milk carbohydrate fraction called “gynolactose” was identified. This was the starting point of research on human milk oligosaccharides (HMOs). In the following years, the first HMOs were characterized and their functions investigated. Studies after 1950 focused on the identification of various HMOs as the “bifidus factor” in human milk. During the next 30 years, a tremendous amount of research was done with regard to the characterization of individual HMOs and HMO patterns in human milk. In this introduction to the history of Bifidobacteria and HMO research, pioneering contributions to this field are presented.