Reference entry
GOS (Galactooligosaccharides)
Plain-English definitions of microbiome research vocabulary — the terms you'll see across articles, testing services, and probiotic claims.
Glossary context
Defined
in the site-wide microbiome glossary
Definition
Prebiotic carbohydrates structurally similar to human milk oligosaccharides. Found naturally in legumes and available as supplements. GOS has evidence for promoting Bifidobacterium growth and reducing symptoms of IBS.
Related terms
Prebiotic
Non-digestible food components (typically dietary fibres) that selectively stimulate the growth or activity of beneficial gut bacteria. Common examples include inulin, FOS, and GOS.
FOS (Fructooligosaccharides)
Short-chain prebiotics found naturally in onions, garlic, bananas, and asparagus. Like inulin, FOS selectively promotes the growth of beneficial bacteria, particularly Bifidobacterium species.