Galacto-Oligosaccharides (GOS) structurally mimic the human milk oligosaccharides (HMOs) naturally present in breast milk. This makes them the most clinically validated prebiotic for infant formula applications. GOS is produced by transgalactosylation of lactose using beta-galactosidase enzymes derived from Bacillus circulans, Kluyveromyces lactis, or Aspergillus oryzae.
The resulting chains resist digestion in the upper GI tract and reach the colon intact, where they are selectively fermented by bifidobacteria to produce short-chain fatty acids (acetate, butyrate, propionate). Clinical studies have demonstrated GOS benefits in softer stools, improved calcium absorption, enhanced immune response, and reduced infection rates in infants. GOS is approved as a novel food ingredient under EU Regulation 2015/2283, recognized as GRAS by FDA (GRN 233, 236, 285, 334), and permitted in infant formula under Codex STAN 72-1981.