Human Milk Oligosaccharides (HMOs) are a unique group of complex carbohydrates that are abundantly present in human breast milk. HMOs are the third most abundant solid component in breast milk after lactose and lipids. They are not digestible by infants but play a crucial role in their overall health and development.

What is an HMO's Job?
HMOs have several important functions:

1. Prebiotic Effect: HMOs act as prebiotics, selectively promoting the growth of beneficial gut bacteria like Bifidobacteria and Lactobacilli. This helps in establishing a healthy gut microbiome in infants.
2. Pathogen Defense: HMOs mimic the binding sites of pathogens (harmful bacteria and viruses), preventing them from attaching to the gut wall and causing infections.
3. Immune System Support: By supporting the growth of beneficial bacteria and preventing pathogen attachment, HMOs contribute to the development of a robust immune system.
4. Brain Development: Emerging research suggests that HMOs may play a role in brain development by supporting the gut-brain axis.

In 2016, Similac was the first infant formula to include an HMO, 2’-FL, that is structurally identical to that found in breast milk¹ to support the developing immune system in infants².

Why It Matters
The inclusion of 2’-FL in Similac represents a significant advancement in infant nutrition. By mimicking the functional benefits of HMOs found in human breast milk, Similac is able to provide formula-fed infants with crucial health benefits that were previously only available through breastfeeding.

HMO and Its Impact on Immunity, Brain Development, and Gut Health

Immunity
HMOs play a critical role in developing and supporting the infant’s immune system. They help protect against infections by acting as decoys that prevent harmful pathogens from binding to the gut wall. By fostering a healthy gut microbiome, HMOs further strengthen the immune response.

Brain Development
Research in preclinical models suggests that supplementation of 2’-FL early in life influences brain development and cognition^3-5.

Gut Health
A healthy gut is foundational to overall health, and HMOs significantly contribute to gut health. They act as food for beneficial bacteria, promoting a balanced gut microbiome. This not only aids digestion but also supports the immune system and brain development.

References:
¹ Weichert S, Jennewein S, Hufner E, et al. Bioengineered 2’-fucosyllactose and 3-fucosyllactose inhibit the adhesion of Pseudomonas aeruginosa and enteric pathogens to human intestinal and respiratory cell lines. Nutrition research. Oct 2013;33(10):831-838.
² Buck R, Goehring K, Marriage B, Oliver J, Wilder J, Barrett E. Novel approaches to the elucidation of HMO biological effects. Abstract presented at FASEB Scientific Research Conferences. July 19-24, 2015.
³ Oliveros et al., Journal of Nutritional Biochemistry, 2016
⁴ Vazquez et al., Journal of Nutritional Biochemistry, 2015
⁵ Vazquez et al., Plos One, 2016