Galactooligosaccharides (GOS)

Written by Slawomir (“Swavak”) Gromadzki, MPH

Galactooligosaccharides (GOS) are defined as prebiotics or non-digestible type of fibre that stimulate the growth and activity of beneficial bacteria in the colon. The increased activity of these health-promoting bacteria results in a number of health benefits such as stimulation of immune function, improved gastro-intestinal health, syntheses of certain vitamins, or enhanced absorption of essential nutrients. These positive effects are created by the bacteria themselves or by the organic acids they produce through fermentation.

GOS are currently regarded by experts as the most potent and beneficial among prebiotic fibres that nourish beneficial bacteria residing in human intestines. GOS is naturally found especially in lentils and beans but also in human milk.

According to the recent findings GOS supplementation was associated with increased number of beneficial bacteria including bifidobacteria and lactobacillus, and decreased number of pathogens such as clostridia (1). Enriching bowel flora in bifidobacteria strains has been linked to decreased blood insulin levels and improved mood (3). GOS also helped reduce colic (2), had beneficial influence on human immune system (4) and inflammatory responses (5). According to the 2014 study supplementation with the same prebiotic reduced the adverse effects of the antibiotic, amoxicillin, on bifidobacteria populations (6). By nourishing Bifidobacteria GOS indirectly help to produce other important compounds, such as conjugated linoleic acid (CLA) which is beneficial in weight management and diabetes prevention. (7)


  1. Giovannini M1, Verduci E, Gregori D, et al (2014) Prebiotic effect of an infant formula supplemented with galacto-oligosaccharides: randomized multicenter trial. J Am Coll Nutr. 2014; 33(5): 385-93.
  2. Williams T, Choe Y, Price P, et al (2014) Tolerance of formulas containing prebiotics in healthy, term infants. J Pediatr Gastroenterol Nutr. 2014 Nov; 59(5): 653-8.
  3. Savignac HM1, Kiely B, Dinan TG, Cryan JF. (2014) Bifidobacteria exert strain-specific effects on stress-related behavior and physiology in BALB/c mice. Neurogastroenterol Motil. 2014 Nov;26(11):1615-27.
  4. Pantipa Chatchatee, Way S. Lee, Eugenia Carrilho (2014) Effects of Growing-Up Milk Supplemented With Prebiotics and LCPUFAs on Infections in Young Children. J Pediatr Gastroenterol Nutr. 2014 Apr; 58(4): 428–437.
  5. Jelena Vulevic, Alexandra Drakoularakou, Parveen Yaqoob, et al (2008) Modulation of the fecal microflora profile and immune function by a novel trans-galactooligosaccharide mixture (B-GOS) in healthy elderly volunteers.
  6. Ladirat SE1, Schoterman MH2, Rahaoui H3, et al (2014) Exploring the effects of galacto-oligosaccharides on the gut microbiota of healthy adults receiving amoxicillin treatment. Br J Nutr. 2014 Aug 28; 112(4): 536-46.
  7. Park HS1, Ryu JH, Ha YL, Park JH. (2001) Dietary conjugated linoleic acid (CLA) induces apoptosis of colonic mucosa in 1,2-dimethylhydrazine-treated rats: a possible mechanism of the anticarcinogenic effect by CLA. Br J Nutr. 2001 Nov;86(5):549-55.

© 2016 Slawomir Gromadzki – All Rights Reserved


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