Prebiotic

Prebiotic is a term used in two related but distinct contexts. In nutrition and microbiology, a prebiotic is a substrate that is selectively utilized by host microorganisms to confer a health benefit. In human nutrition, most common prebiotics are nondigestible carbohydrates such as inulin, fructooligosaccharides (FOS), galactooligosaccharides (GOS), resistant starch, and certain dietary fibers. They escape digestion in the upper gastrointestinal tract and reach the colon, where they are fermented by gut bacteria. The fermentation produces short-chain fatty acids such as acetate, propionate, and butyrate, which can lower colonic pH and promote the growth of beneficial microbes such as Bifidobacterium and Lactobacillus. Potential health effects include improved bowel regularity, enhanced mineral absorption, and modulated immune function, though results vary and depend on dose and individual microbiota.

Safety and regulatory considerations: Prebiotics are generally regarded as safe for many populations, but high doses can cause gas, bloating, or gastrointestinal discomfort. Individuals with certain digestive disorders should seek professional guidance, and responses can vary among individuals.

In origin-of-life research, the term prebiotic also refers to chemical species and reactions that could have preceded biological life. This field investigates how simple organic molecules may assemble into nucleotides, amino acids, and lipid precursors under plausible early Earth conditions, using energy sources such as UV light, electrical discharges, or geochemical gradients. The aim is to understand plausible routes to the emergence of metabolic systems and genetic information, separate from living organisms.