Fructooligosaccharides (FOS) are short-chain carbohydrates that consist of fructose units and naturally occur in various plants like chicory, garlic, onions, and bananas. They belong to the group of prebiotics, meaning substances that are not digested by the body themselves but serve as food for beneficial gut bacteria, thus promoting the growth and activity of these microorganisms.
In infant nutrition, FOS play a special role as they are added to infant formulas to positively influence the composition of the gut microbiome. This practice aims to replicate some of the benefits of human milk oligosaccharides (HMOs) that naturally occur in breast milk. HMOs are complex sugars that are an essential component of breast milk and play an important role in the health and development of infants, especially by supporting the growth of Bifidobacteria.
Although FOS as prebiotics resemble HMOs by promoting the microbiome and supporting the immune system, they are structurally less complex than HMOs and cannot fully replicate the specific benefits of breast milk. Breast milk remains the best nutritional option for infants, as it is perfectly tailored to the baby's needs and contains a variety of nutrients as well as immunological and developmentally relevant factors.
Therefore, FOS are used in infant formulas to support gut health in non-breastfed infants and promote the growth of Bifidobacteria. This is intended to bring the microbiome of non-breastfed infants closer to that of breastfed infants, always bearing in mind that breast milk is the ideal source of nutrition for infants.
