GLOSSARY

Galactooligosaccharides (GOS) are short galactose-containing chains, many commercial food types being produced enzymatically from lactose. Product structures vary, and potential prebiotic effects require evidence for the particular ingredient and quantity.

A common classification distinguishes one-unit monosaccharides, two-unit disaccharides, short-chain oligosaccharides and longer polysaccharides. The FAO framework generally places oligosaccharides at 3–9 units and polysaccharides at 10 or more. Some sources use different boundaries, so the convention being applied should be stated rather than assumed universal.

Carbohydrate structure involves more than the number of sugar units: bond type and molecular arrangement also matter. Starch and cellulose both contain glucose, yet human enzymes do not break them down in the same way. Polymer status or chain length alone therefore does not determine digestion rate or nutritional value.

A GOS product may also contain sugars remaining from manufacture, so the name alone proves neither lactose-free status nor pure fibre quantity. A digestive-sensitive athlete needs product-specific information and tolerance rather than transferring one study's result to every formulation.

Large-intestinal microbes can convert some remaining carbohydrates into short-chain fatty acids and gases. This differs from direct glucose absorption and cannot be treated as equivalent rapid running fuel. Both the amount and rate of fermentation depend on the substrate's structure and the individual's microbial community.

Fermentation alone does not establish prebiotic status: selective utilisation by host microorganisms and a health benefit must be demonstrated. Increasing one bacterial group alone does not prove improved sport performance either. Evidence depends on ingredient, dose, studied population and actual outcome, rather than every fibre-containing product having the same effect.

Some sugars, polyols and short fermentable chains can provoke digestive symptoms in susceptible people. This does not make all fermentable foods unhealthy. Broad, prolonged restriction without identifying the problem can make dietary diversity and adequacy harder to achieve; persistent symptoms warrant an individual approach to the eating plan.

An ingredient name identifies something used in production but does not always reveal its exact amount. Meal calculations also need the nutrition panel and actual portion. A powder named after a sugar or polymer may contain water, minerals or other ingredients, so total powder weight is not necessarily carbohydrate weight.