Prebiotics History: Fiber, Bacteria and the 2017 Definition
A 1995 paper defined prebiotics as nondigestible food ingredients that selectively stimulate colon bacteria. This page sticks to what PubMed records show: how the definition changed, which fibers have the most support, and why prebiotics get paired with probiotics.
The history of prebiotics is a story about fiber that feeds the bacteria already living in the colon, and about a definition that keeps getting rewritten. In 1995, Gibson and Roberfroid introduced the concept in the *Journal of Nutrition* ([according to PubMed](https://doi.org/10.1093/jn/125.6.1401)). The 2017 ISAPP consensus widened the term to possibly include non-carbohydrate substances, body sites beyond the gut and categories beyond food ([according to PubMed](https://doi.org/10.1038/nrgastro.2017.75)). ## What did the 1995 paper introduce? The [1995 abstract](https://doi.org/10.1093/jn/125.6.1401) defines prebiotics as nondigestible food ingredients that beneficially affect the host by selectively stimulating the growth or activity of one or a limited number of bacterial species already in the colon. It names nondigestible oligosaccharides in general, and fructooligosaccharides in particular, as prebiotics. The paper also proposed the concept of synbiotics, a term for pro- and prebiotic combinations. We did not find a source that says who first used the word, so this page leaves that open. ## What is inulin, and where does it come from? Inulin-type fructans are fermentable dietary fibers. A 2025 mouse study in a model of obesity compared purified inulin extracted from chicory root with a natural scorzonera source. Both boosted bifidobacteria, while only the scorzonera source increased *Akkermansia* ([according to PubMed](https://doi.org/10.1007/s00394-025-03640-x)). For the Akkermansia side of that result, see the [Akkermansia monograph](/ingredients/akkermansia-muciniphila). ## What did the early bifidobacteria studies test? The [1995 review](https://doi.org/10.1093/jn/125.6.1401) reports that nondigestible oligosaccharides, fructooligosaccharides in particular, stimulated the growth of endogenous bifidobacteria, which became predominant in human feces after a short feeding period. A 2007 review reports that experimental and human work found inulin and oligofructose favor the growth of indigenous lactobacilli and bifidobacteria ([according to PubMed](https://doi.org/10.1017/S0007114507832958)). For the gut-bacteria background, see [the gut microbiome post](/blog/digestive/digestive-health-and-the-gut-microbiome). ## How did the definition change? The [1995 definition](https://doi.org/10.1093/jn/125.6.1401) described a nondigestible food ingredient that selectively stimulated a few colon bacteria. A 2008 review describes a selectively fermented ingredient that allows specific changes in the gut flora and confers benefits upon host well-being and health ([according to PubMed](https://doi.org/10.1007/10_2008_097)). The 2017 ISAPP consensus describes a substrate that host microorganisms selectively use, conferring a health benefit, and it requires that the benefit be documented. ## Why are prebiotics paired with probiotics? The [1995 abstract](https://doi.org/10.1093/jn/125.6.1401) argues that probiotic changes may be transient and that implanted bacteria establish only to a limited extent. Prebiotics, by contrast, stimulate bacteria already resident in the colon. The paper proposed synbiotics to combine the two rationales, and the [probiotics monograph](/ingredients/probiotics) covers the bacterial side of that pairing in more depth. ## Which fibers have the most support? A 2008 review says that only bifidogenic, nondigestible oligosaccharides meet all the criteria for prebiotic classification. It names inulin, its hydrolysis product oligofructose, and (trans)galactooligosaccharides as the leading examples ([according to PubMed](https://doi.org/10.1007/10_2008_097)). The 2017 consensus sets a broader definition that requires documented benefits, so read that list as a 2008 snapshot. ## Bottom line The history of prebiotics is a definition that keeps widening. When a label says prebiotic, check which compound it names. The 2008 list was inulin, oligofructose and (trans)galactooligosaccharides. The 2017 consensus asks for documented benefits, so a prebiotic claim with no study behind it does not meet that test. ## Frequently asked questions ### What is inulin, and where does it come from? Inulin-type fructans are fermentable dietary fibers that can change the gut microbiota, according to a 2025 mouse study ([according to PubMed](https://doi.org/10.1007/s00394-025-03640-x)). The purified inulin in that study was extracted from chicory root. In those mice, inulin boosted bifidobacteria. We did not find a source that explains why chicory became an early fiber example, so this page does not offer a reason. ### Who introduced the prebiotic concept, and what did it mean at first? Gibson and Roberfroid introduced the concept in a 1995 *Journal of Nutrition* paper titled "Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics" ([according to PubMed](https://doi.org/10.1093/jn/125.6.1401)). At first, a prebiotic meant a nondigestible food ingredient that selectively stimulated the growth or activity of one or a limited number of bacterial species already in the colon. The abstract named fructooligosaccharides in particular as prebiotics. We did not find a source that says who first used the word. ### What did the early bifidobacteria studies test? The [1995 review](https://doi.org/10.1093/jn/125.6.1401) reported that nondigestible oligosaccharides, fructooligosaccharides in particular, stimulated endogenous bifidobacteria, which became predominant in human feces after a short feeding period. A 2007 review reports that experimental and human work found inulin and oligofructose favor the growth of indigenous lactobacilli and bifidobacteria ([according to PubMed](https://doi.org/10.1017/S0007114507832958)). The human result named in the 1995 abstract is bifidobacteria becoming predominant in feces. ### How did the prebiotic definition change over time? The [1995 definition](https://doi.org/10.1093/jn/125.6.1401) described a nondigestible food ingredient that selectively stimulated a few colon bacteria. A 2008 review described a selectively fermented ingredient that allows specific changes in the gut flora and confers benefits upon host well-being and health ([according to PubMed](https://doi.org/10.1007/10_2008_097)). The 2017 ISAPP consensus describes a substrate that host microorganisms selectively use, conferring a health benefit, and says that benefit must be documented. It also expands the concept to possibly include non-carbohydrate substances, body sites beyond the gut and categories beyond food. ### Why are prebiotic fibers and probiotics often paired? The [1995 abstract](https://doi.org/10.1093/jn/125.6.1401) argues that probiotic changes may be transient and that implanted bacteria establish only to a limited extent. Prebiotics, by contrast, stimulate bacteria already resident in the colon. Gibson and Roberfroid proposed synbiotics to combine the two rationales ([according to PubMed](https://doi.org/10.1093/jn/125.6.1401)). A 2008 review uses the term synbiotics for synergistic combinations of pro- and prebiotics ([according to PubMed](https://doi.org/10.1007/10_2008_097)). The 1995 abstract describes some colonic foods with interesting nutritional properties as candidates for classification as health-enhancing functional food ingredients. ### Which fiber sources are the best studied? A 2008 review says that only bifidogenic, nondigestible oligosaccharides meet all the criteria for prebiotic classification. It names inulin, its hydrolysis product oligofructose, and (trans)galactooligosaccharides as the leading examples ([according to PubMed](https://doi.org/10.1007/10_2008_097)). The 2007 review names inulin and oligofructose as the fibers with experimental and human data on bifidobacteria and lactobacilli ([according to PubMed](https://doi.org/10.1017/S0007114507832958)). The 2017 consensus sets a broader definition, so read that list as a 2008 snapshot of the evidence, not a current ranking. ## Next reads - [Probiotics ingredient monograph](/ingredients/probiotics): the bacterial side of the prebiotic pairing. - [Digestive health and the gut microbiome](/blog/digestive/digestive-health-and-the-gut-microbiome): the lateral read on gut bacteria and fiber. ### Related reading - [the pomegranate origins story](/blog/history/history-of-pomegranate-from-ancient-orchards-to-urolithin-a) - [the probiotic origins story](/blog/history/history-of-probiotics-from-yogurt-to-lactobacillus)