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.

The New Addition of 5 HMOs to Similac
Similac has recently enhanced its formula with the addition of five specific HMOs, which include:

1. 2’-FL (2’-Fucosyllactose): Known for its role in immune support.
2. LNT (Lacto-N-tetraose): Promotes the growth of beneficial bacteria.
3. 3’-SL (3’-Sialyllactose): Supports brain development and function.
4. 6’-SL (6’-Sialyllactose): Plays a role in gut health.
5. DFL (Difucosyllactose): Enhances pathogen defense mechanisms.

Why It Matters
The inclusion of these five HMOs 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 indicates that HMOs like 3’-SL and 6’-SL are involved in cognitive development. They support the gut-brain axis, a communication network that links the gut and the brain, thus influencing brain function and development.

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. Coppa, G. V., et al. “Oligosaccharides in human milk during different phases of lactation.” Acta Paediatr Suppl. 1999;88(430):89-94.
2. Kunz, C., et al. “Influence of Gestational Age, Secretor, and Lewis Blood Group Status on the Oligosaccharide Content of Human Milk.” J Pediatr Gastroenterol Nutr. 2017;64(5):789-798.
3. Duska-McEwen G, et al. Food Nutr Sci. 2014;5:1387–1398.
4. Ruiz-Palacios GM, et al. “Campylobacter jejuni binds intestinal H-2 antigen.” J Biol Chem. 2003;278(16):14112–14120.
5. Wang B, et al. “Sialylated Oligosaccharides in Human Milk: Relationship with Cognitive Development in Infants.” Adv Nutr. 2012;3(3):465S-472S.
6. Lasekan J, Choe Y, Dvoretskiy S, et al. “Growth and Gastrointestinal Tolerance in Healthy Term Infants Fed Milk-Based Infant Formula Supplemented with Five Human Milk Oligosaccharides (HMOs): A Randomized Multicenter Trial.” Nutrients. 2022 Jun 24;14(13):2625.