Galacto-oligosaccharides (GOS) prebiotics in infant milk formula: from ingredient to application

As infant nutrition continues to evolve, galacto-oligosaccharides (GOS) have become one of the most widely used early life nutrition ingredients – found in around half of infant formulations worldwide.

Innova Product Database, 2025



Whether you’re formulating for infant gut health, immune support or all-round wellbeing, understanding the full range of GOS prebiotic

The scientific definition of a prebiotic is a substrate that is selectively utilized by host microorganisms conferring a health benefit (Gibson GR, et al. Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics. Nat Rev Gastroenterol Hepatol. 2017 Aug;14(8):491-502.). Whether the claim ‘prebiotic’ can be used on consumer products depends on local legislation.



ingredient benefits can help you create products that meet growing parental expectations and increasingly rigorous clinical standards.

If you’re looking to leverage GOS for your next infant nutrition innovation, here’s everything you need to know about functionality, formulation and supplier selection.

What are GOS?

Galacto-oligosaccharides (GOS) are non-digestible carbohydrates produced through the enzymatic conversion of lactose. They are primarily composed of galactose units, often linked to a terminal glucose, giving them structural similarities to lactose-based oligosaccharides found in human milk.
Once in the gut, GOS selectively fuel the growth of beneficial bacteria such as Bifidobacteria and Lactobacilli, supporting a balanced microbiome from the earliest days of life.

Advances in oligosaccharide research have shown that GOS ingredients are not a single compound but a diverse blend of over 100 distinct structures

Logtenberg, M. J. et al. Touching the high complexity of prebiotic Vivinal galacto- oligosaccharides using UHPLC-PGC-MS. J Agric Food Chem 68, 7800–7808 (2020).



, including galactosyllactoses also found naturally in the HMO pool

van Leeuwen, S. S., Kuipers, B. J. H., Dijkhuizen, L. & Kamerling, J. P. (1)H NMR analysis of the lactose/β-galactosidase-derived galacto-oligosaccharide components of Vivinal® GOS up to DP5. Carbohydr Res 400, 59–73 (2014).



. This structural diversity is why GOS prebiotic ingredients are increasingly viewed as useful for supporting healthy microbiota development and overall wellbeing when breastfeeding isn’t possible.

Key stats

• 59% of parents are interested in purchasing products claiming to support infant gut health
  
  Innova Market Insights & RFC, Early Life Nutrition survey, 2020
  
  
  
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• In the first 12 months, over half of infants show at least one symptom of gut discomfort, such as regurgitation, colic or constipation.
  
  Innova Market Insights & RFC, Early Life Nutrition survey, 2020
  
  
  

Key benefits of GOS supplementation in infant milk formula

Breastfeeding is the gold standard of infant nutrition, but where this isn’t possible, infant milk formula is an invaluable alternative. For formula developers, delivering more oligosaccharide diversity and proven functional benefits is the key to successful new product development.

A well-established body of clinical evidence supports GOS supplementation across several key areas of infant health:

Infant gut health

GOS selectively feed “good” bacteria like Bifidobacteria and Lactobacilli, helping to promote a healthy microbiome and improve stool consistency in the first year of life.

Sierra, C. et al. (2014). Prebiotic effect during the first year of life in healthy infants fed formula containing GOS as the only prebiotic. European Journal of Nutrition, 54(1), 89–99.



Early gut microbiota development also underpins better nutrient digestion and mineral absorption, forming the foundation the immune system and other developmental processes build on.

Zhuang, L., Chen, H., Zhang, S., Zhuang, J., Li, Q., & Feng, Z. (2019). Intestinal Microbiota in Early Life and Its Implications on Childhood Health. Genomics, Proteomics & Bioinformatics, 17, 13 – 25. https://doi.org/10.1016/j.gpb.2018.10.002

Infant immune health

GOS supplementation can support a balanced gut microbiome – key for the maturing immune system during a period when infants are especially vulnerable to infection. As roughly 70% of immune cells are located in the gut, early microbiome development has knock-on effects for immune resilience.

Yang, Z., Liu, X., Wu, Y., Peng, J., & Wei, H. (2022). Effect of the Microbiome on Intestinal Innate Immune Development in Early Life and the Potential Strategy of Early Intervention. Frontiers in Immunology, 13. https://doi.org/10.3389/fimmu.2022.936300



One study found that GOS inhibits the adhesion of E. coli to human intestinal cells, which could help reduce pathogen-mediated infections.

Ambrogi, V., Bottacini, F., Sharry, J. Mac, Breen, J. Van, Keeffe, E. O., Walsh, D., Schoemaker, B., Cao, L., Kuipers, B., Hernandez-hernandez, O., Moreno, F. J., & Schoterman, M. (2021). Bifidobacterial β -Galactosidase-Mediated Production of Galacto-Oligosaccharides : Structural and Preliminary Functional Assessments. Frontiers in Microbiology, 12(750635), 1–19. https://doi.org/10.3389/fmicb.2021.750635

Digestive comfort

A balanced gut microbiota can help ease common digestive complaints in infants with an immature gut, supporting formulators looking to meet parental demand for gentler, more comfortable digestion.

Williams T, Choe Y, Price P, et al. Tolerance of formulas containing prebiotics in healthy, term infants. J Pediatr Gastroenterol Nutr. Published online 2014. https://doi.org/10.1097/MPG.0000000000000513

Healthy growth

Beyond the microbiota, GOS prebiotic ingredients have been shown to support the absorption of key minerals such as calcium and iron

Whisner, C. M. et al. Galacto-oligosaccharides increase calcium absorption and gut bifidobacteria in young girls: a double-blind cross-over trial. Br J Nutr 110, 1292–303 (2013).
Paganini, D. et al. Consumption of galacto-oligosaccharides increases iron absorption from a micronutrient powder containing ferrous fumarate and sodium iron EDTA: a stable isotope study in Kenyan infants. American Journal of Clinical Nutrition 106, 1020–1031 (2017).



, – nutrients that are critical for healthy growth and development in the early years.

Cognitive and emotional well-being

Emerging research suggests GOS supplementation in early life may influence the gut-brain axis via SCFA production upon bacterial fermentation of GOS, extending the value of GOS beyond the gut.

Silva YP, Bernardi A, Frozza RL. The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication. Front Endocrinol (Lausanne). Published online 2020

The latest evidence on GOS structural diversity

More than 100 diverse oligosaccharide structures have been uncovered in our Vivinal® GOS ingredient.

Logtenberg, M. J. et al. Touching the high complexity of prebiotic Vivinal galacto- oligosaccharides using UHPLC-PGC-MS. J Agric Food Chem 68, 7800–7808 (2020).



It is expected that these individual structures affect the gut microbiota, which supports certain health benefits.

Some of these structures are also present in human milk, including 3’-galactosyllactose (3’-GL), 4’-galactosyllactose (4’-GL) and 6’-galactosyllactose (6’-GL).

van Leeuwen, S. S., Kuipers, B. J. H., Dijkhuizen, L. & Kamerling, J. P. (1)H NMR analysis of the lactose/β-galactosidase-derived galacto-oligosaccharide components of Vivinal® GOS up to DP5. Carbohydr Res 400, 59–73 (2014).



Preclinical studies suggest that 3’-GL, 4’-GL and 6’-GL can support immunity and gut health in infants.

Meeusen, E. et al. Gram-scale chemical synthesis of galactosyllactoses and their impact on infant gut microbiota in vitro. Org Biomol Chem (2024).
Varasteh, S. et al. Human milk oligosaccharide 3’-galactosyllactose can protect the intestinal barrier to challenges. ESPGHAN conference abstracts (2019).

Interestingly, Vivinal® GOS has a specific composition and is particularly high in 4’-GL, which appears to be the most bifidogenic among all galactosyllactoses.

Meeusen, E. et al. Gram-scale chemical synthesis of galactosyllactoses and their impact on infant gut microbiota in vitro. Org Biomol Chem (2024).



In addition, Vivinal® GOS stands out by offering the strongest evidence for health benefits, supported by over 70 clinicals studies. Adding 6.5% Vivinal® GOS syrup to an infant formula could match the GL levels present in mature human milk,

Sumiyoshi, W. et al. Galactosyllactoses in the Milk of Japanese Women: Changes in Concentration during the Course of Lactation. J Appl Glycosci (1999) 51, 341–344 (2004).



while supporting key health benefits for infants and possibly enable claims of 3 HMOs (3’-GL, 4’-GL, 6’-GL) on packaging or point-of-sale materials.

Crucially, as these same galactosyllactoses are found in human milk as part of the HMO pool,

van Leeuwen, S. S., Kuipers, B. J. H., Dijkhuizen, L. & Kamerling, J. P. (1)H NMR analysis of the lactose/β-galactosidase-derived galacto-oligosaccharide components of Vivinal® GOS up to DP5. Carbohydr Res 400, 59–73 (2014).



these findings are helping us better understand how GOS may support infant health through greater oligosaccharide diversity.

Explore these findings in our white paper

Formulating GOS prebiotic ingredients with HMOs

Formulators are increasingly looking to combine galacto-oligosaccharides with HMOs to deliver a broader diversity of oligosaccharide structures in infant formula. This diversity is important because oligosaccharides are understood to support early life development through several distinct mechanisms.

Research shows that combining GOS with selected HMOs has several benefits, including:

• Feed more “good” bacteria: Some Bifidobacteria species can’t thrive on 2’-FL alone. But adding GOS to the mix supports cross-feeding and beneficial metabolite production; helping more beneficial bacteria to flourish and supporting a richer and more balanced gut microbiota.
  
  Lindner, C. et al. Infant Fecal Fermentations with Galacto-Oligosaccharides and 2′-Fucosyllactose Show Differential Bifidobacterium longum Stimulation at Subspecies Level. Children 10, 430 (2023).
  van Sinderen, D. Internal Report: Bifidogenic Effects of GOS and 2’-FL in Vitro. (2021).
  
  
  
• Reduce “bad” bacteria: In vitro studies demonstrated that GOS plus 2’-FL significantly reduce Proteobacteria, a large and diverse group of bacteria linked to gut microbiota imbalance (dysbiosis) and inflammation.
  
  Lindner, C. et al. Infant Fecal Fermentations with Galacto-Oligosaccharides and 2′-Fucosyllactose Show Differential Bifidobacterium longum Stimulation at Subspecies Level. Children 10, 430 (2023).
  
  
  
  Together, they may even support faster gut microbiota balance recovery following antibiotic use.
  
  Endika, M. F. et al. Microbiota-dependent influence of prebiotics on the resilience of infant gut microbiota to amoxicillin/clavulanate perturbation in an in vitro colon model. Front Microbiol 14, (2023).
  
  
  

Formulation considerations for galacto-oligosaccharides

Inclusion levels: Permitted or commonly used GOS inclusion levels in infant formula and follow-on formula vary by region, typically guided by Codex Alimentarius principles and adapted under regional regulations such as the EU Delegated Regulation on infant formula, US FDA ingredient status and infant formula requirements and China’s GB standards. Formulators should confirm current permitted ranges for each target market before finalising a formulation.

Compatibility: GOS are highly compatible with other functional ingredients, including FOS, HMOs, and probiotic strains, enabling synbiotic and multi-oligosaccharide formulations without processing conflicts.

Processing and stability: GOS demonstrates good thermal stability across standard infant milk formula processing conditions, including spray-drying and wet-mix pasteurisation, making them suitable for both GOS syrup and GOS powder production routes. With a mild sweetness profile, they have minimal impact on the sensory profile of the finished formula.

Regulatory landscape: Permitted GOS levels and labelling requirements differ across the EU, US, Codex-aligned markets and China, so early regulatory alignment is essential when formulating for multiple markets.

Interested in adding GOS prebiotic ingredients in your next infant milk formula?

Talk to our technical team today!