ANSWER

Prebiotics are commonly oligosaccharides and they are being selectively metabolized in the gastrointestinal tract by beneficial bacteria associated with health and well-being. Positive modulation on the colonic microbiota by these carbohydrates indeed exerts significant influence on host health (Kittibunchakul et al., 2018). Galactooligosaccharide (GOS) is a prebiotic, produced through the enzymatic conversion of lactose and mainly consists of galactose and glucose molecules (Gosling et al., 2010). It is consist of a number of β-(1–6) linked and β-(1–4) galactopyranosyl units linked to a terminal glucopyranosyl residue through an α-(1–4) glycosidic bond (Drakoularakou et al., 2011).

Recommended effective dose of GOS in adults is 8-15g/day (Illanes, 2016), but significantly lower doses have produced beneficial effects in youngster (Whisner et al., 2013) and infants (Ben et al., 2008). The recommended dose to detect a bifidogenic effect is thought to be at least 10g of GOS per day. Intake in excess of 30g/day may produce intestinal discomfort and diarrhea (Macfarlane et al., 2008).

References

Ben, X., Li, J., Feng, Z., Shi, S., Lu, Y., Chen, R., & Zhou, X. (2008). Low level of galacto-oligosaccharide in infant formula stimulates growth of intestinal Bifidobacteria and Lactobacilli. World Journal Of Gastroenterology, 14(42), 6564-6568.

Drakoularakou, A., Rastall, R., & Gibson, G. (2011). Functional foods for the gut: probiotics, prebiotics and synbiotics. Functional Foods, 449-470. https://doi.org/10.1533/9780857092557.3.449

Gosling, A., Stevens, G., Barber, A., Kentish, S., & Gras, S. (2010). Recent advances refining galactooligosaccharide production from lactose. Food Chemistry, 121(2), 307-318.

Illanes, A., Guerrero, C., Vera, C., Wilson, L., Conejeros, R., & Scott, F. (2016). Lactose-derived prebiotics(p. 116). London: Elsevier.

Kittibunchakul, S., Maischberger, T., Domig, K., Kneifel, W., Nguyen, H., Haltrich, D., & Nguyen, T. (2018). Fermentability of a Novel Galacto-Oligosaccharide Mixture by Lactobacillus and Bifidobacterium spp. Molecules, 23(12), 3352. https://doi.org/10.3390/molecules23123352

Macfarlane, G., Steed, H., & Macfarlane, S. (2008). Bacterial metabolism and health-related effects of galacto-oligosaccharides and other prebiotics. Journal Of Applied Microbiology, 104(2), 305-344. https://doi.org/10.1111/j.1365-2672.2007.03520.x

Whisner, C. M., Martin, B. R., Schoterman, M. H. C., Nakatsu, C. H., McCabe, L. D., & McCabe, G. P., Wastney, M. E., van den Heuvel, E. G. H. M., Weaver, C. M., (2013). Galacto-oligosaccharides increase calcium absorption and gut bifidobacteria in young girls: a double-blind cross-over trial. British Journal Of Nutrition, 110(7), 1292-1303. https://doi.org/10.1017/s000711451300055x