Prebiotics are substances that induce the growth or activity of microorganisms (e.g., bacteria and fungi) that contribute to the well-being of their host. The most common example is in the gastrointestinal tract, where prebiotics can alter the composition of organisms in the gut microbiome. However, in principle it is a more general term that can refer to other areas of the body as well. For example, certain hand moisturizers have been proposed to act like prebiotics to improve the activity or composition of skin microbiota.
In diet, prebiotics are typically non-digestible, fiber compounds that pass undigested through the upper part of the gastrointestinal tract and stimulate the growth or activity of advantageous bacteria that colonize the large bowel by acting as substrate for them. They were first identified and named by Marcel Roberfroid in 1995. As a functional food component, prebiotics, like probiotics, are conceptually intermediate between foods and drugs. Depending on the jurisdiction, they typically receive an intermediate level of regulatory scrutiny, in particular of the health claims made concerning them.
Roberfroid offered a refined definition in the March 2007 Journal of Nutrition stating: "A prebiotic is a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gastrointestinal microflora that confers benefits upon host well-being and health."
Additionally, in his 2007 revisit of prebiotics, Roberfroid stated that only two particular prebiotics then fully met this definition: trans-galactooligosaccharide and inulin. Other dietary fibers also fit the definition of prebiotics as developed by Roberfroid such as Larch arabinogalactin (LAG), resistant starch, pectin, beta-glucans, and Xylooligosaccharides (XOS).
The prebiotic definition does not emphasize a specific bacterial group. Generally, however, it is assumed that a prebiotic should increase the number or activity of bifidobacteria and lactic acid bacteria. The importance of the bifidobacteria and the lactic acid bacteria (LABs) is that these groups of bacteria may have several beneficial effects on the host, especially in terms of improving digestion (including enhancing mineral absorption) and the effectiveness and intrinsic strength of the immune system. A product that stimulates bifidobacteria is considered a bifidogenic factor. Some prebiotics may thus also act as a bifidogenic factor and vice versa, but the two concepts are not identical.
|Top 10 Foods Containing Prebiotics|
|Food||Prebiotic Fiber Content by Weight|
|Raw, Dry Chicory Root||64.6%|
|Raw, Dry Jerusalem Artichoke||31.5%|
|Raw, Dry Dandelion Greens||24.3%|
|Raw, Dry Garlic||17.5%|
|Raw, Dry Leek||11.7%|
|Raw, Dry Onion||8.6%|
|Raw Wheat bran||5%|
|Whole Wheat flour, Cooked||4.8%|
While there is no broad consensus on an ideal daily serving of prebiotics, recommendations typically range from 4 to 8 grams (0.14–0.28 oz) for general digestive health support, to 15 grams (0.53 oz) or more for those with active digestive disorders. Given an average 6 grams (0.21 oz) serving, below are the amounts of prebiotic foods required to achieve a daily serving of prebiotic fiber:
|Food||Amount of food to achieve 6 g serving of prebiotics|
|Raw Chicory Root||9.3 g (0.33 oz)|
|Raw Jerusalem Artichoke||19 g (0.67 oz)|
|Raw Dandelion Greens||24.7 g (0.87 oz)|
|Raw Garlic||34.3 g (1.21 oz)|
|Raw Leek||51.3 g (1.81 oz)|
|Raw Onion||69.8 g (2.46 oz)|
|Cooked Onion||120 g (4.2 oz)|
|Raw Asparagus||120 g (4.2 oz)|
|Raw Wheat Bran||120 g (4.2 oz)|
|Whole Wheat Flour, Cooked||125 g (4.4 oz)|
|Raw Banana||600 g (1.3 lb)|
Preliminary research has demonstrated potential effects on calcium and other mineral absorption, immune system effectiveness, bowel acidity, reduction of colorectal cancer risk, inflammatory bowel disease (Crohn's disease or ulcerative colitis) hypertension and defecation frequency. Prebiotics may be effective in decreasing the number of infectious episodes needing antibiotics and the total number of infections in children aged 0–24 months.
While research demonstrates that prebiotics lead to increased production of short-chain fatty acids (SCFA), more research is required to establish a direct causal connection. Prebiotics may be beneficial to inflammatory bowel disease or Crohn's disease through production of SCFA as nourishment for colonic walls, and mitigation of ulcerative colitis symptoms.
The immediate addition of substantial quantities of prebiotics to the diet may result in an increase in fermentation, leading to increased gas production, bloating or bowel movement. Production of SCFA and fermentation quality are reduced during long-term diets of low fiber intake. Until bacterial flora are gradually established to rehabilitate or restore intestinal bacteria, nutrient absorption may be impaired and colonic transit time temporarily increased with an immediate addition of higher prebiotic intake.
- Hutkins RW, Krumbeck JA, Bindels LB, Cani PD, Fahey G Jr., Goh YJ, Hamaker B, Martens EC, Mills DA, Rastal RA, Vaughan E, Sanders ME (2016). "Prebiotics: why definitions matter". Curr Opin Biotechnol. 37: 1–7. doi:10.1016/j.copbio.2015.09.001. PMC . PMID 26431716.
- Schloss, Patrick D. (1 October 2014). "Microbiology: An integrated view of the skin microbiome". Nature. 514 (7520): 44–45. doi:10.1038/514044a.
- Gibson GR, Roberfroid MB (Jun 1995). "Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics". J Nutr. 125 (6): 1401–1412. PMID 7782892.
- Roberfroid MB (March 2007). "Prebiotics: The Concept Revisited". J Nutr. 137 (3 Suppl 2): 830S–7S. PMID 17311983.
- Roberfroid M (2007). "Prebiotics: The Concept Revisited". J Nutr. 137 (3 Suppl 2): 830S–7S. PMID 17311983.
Presently there are only 2 food ingredients that fulfill these criteria, i.e., inulin and trans-galactooligosaccharides (TOS).
- Kelly, G. S. (1999-04-01). "Larch arabinogalactan: clinical relevance of a novel immune-enhancing polysaccharide". Alternative Medicine Review. 4 (2): 96–103. ISSN 1089-5159. PMID 10231609.
- Zaman, Siti A.; Sarbini, Shahrul R. (2015-07-07). "The potential of resistant starch as a prebiotic". Critical Reviews in Biotechnology: 1–7. doi:10.3109/07388551.2014.993590. ISSN 1549-7801. PMID 25582732.
- Gómez, Belén; Gullón, Beatriz; Remoroza, Connie; Schols, Henk A.; Parajó, Juan C.; Alonso, José L. (2014-10-08). "Purification, characterization, and prebiotic properties of pectic oligosaccharides from orange peel wastes". Journal of Agricultural and Food Chemistry. 62 (40): 9769–9782. doi:10.1021/jf503475b. ISSN 1520-5118. PMID 25207862.
- Arena, Mattia P.; Caggianiello, Graziano; Fiocco, Daniela; Russo, Pasquale; Torelli, Michele; Spano, Giuseppe; Capozzi, Vittorio (2014-02-20). "Barley β-Glucans-Containing Food Enhances Probiotic Performances of Beneficial Bacteria". International Journal of Molecular Sciences. 15 (2): 3025–3039. doi:10.3390/ijms15023025. ISSN 1422-0067. PMC . PMID 24562330.
- Jain, Ira; Kumar, Vikash; Satyanarayana, T. (2015-03-01). "Xylooligosaccharides: an economical prebiotic from agroresidues and their health benefits". Indian Journal of Experimental Biology. 53 (3): 131–142. ISSN 0019-5189. PMID 25872243.
- Coxam V (Nov 2007). "Current data with inulin-type fructans and calcium, targeting bone health in adults". J Nutr. 137 (11 Suppl): 2527S–2533S. PMID 17951497.
- Seifert S, Watzl B (Nov 2007). "Inulin and oligofructose: review of experimental data on immune modulation". J Nutr. 137 (11 Suppl): 2563S–2567S. PMID 17951503.
- "Prebiotics". Wageningen University.
- Moshfegh AJ, Friday JE, Goldman JP, Ahuja JK (July 1999). "Presence of inulin and oligofructose in the diets of Americans". Journal of Nutrition. 129 (7 Suppl): 1407S–1411S. PMID 10395608.
- Scholz-Ahrens KE, Schrezenmeir J (Nov 2007). "Inulin and oligofructose and mineral metabolism: the evidence from animal trials". J Nutr. 137 (11 Suppl): 2513S–2523S. PMID 17951495.
- Lomax AR, Calder PC (Mar 2009). "Prebiotics, immune function, infection and inflammation: a review of the evidence". Br J Nutr. 101 (5): 633–658. doi:10.1017/S0007114508055608. PMID 18814803.
- Lohner S, Küllenberg D, Antes G, Decsi T, Meerpohl JJ (2014). "Prebiotics in healthy infants and children for prevention of acute infectious diseases: a systematic review and meta-analysis". Nutr Rev. 72 (8): 523–31. doi:10.1111/nure.12117. PMID 24903007.
- Geier MS, Butler RN, Howarth GS (Oct 2006). "Probiotics, prebiotics and synbiotics: a role in chemoprevention for colorectal cancer?". Cancer Biol Ther. 5 (10): 1265–1269. doi:10.4161/cbt.5.10.3296. PMID 16969130.
- Hedin C, Whelan K, Lindsay JO (Aug 2007). "Evidence for the use of probiotics and prebiotics in inflammatory bowel disease: a review of clinical trials". Proc Nutr Soc. 66 (3): 307–315. doi:10.1017/S0029665107005563. PMID 17637082.
- Yeo SK, Ooi LG, Lim TJ, Liong MT (2009). "Antihypertensive properties of plant-based prebiotics". Int J Mol Sci. 10 (8): 3517–30. doi:10.3390/ijms10083517. PMID 20111692.
- Roberfroid M, et al. (2010). "Prebiotic effects: metabolic and health benefits". Br J Nutr. 104 (Suppl 2): S1–63. doi:10.1017/S0007114510003363. PMID 20920376.
- Lohner, S.; Küllenberg, D.; Antes, G.; Decsi, T.; Meerpohl, JJ. (Aug 2014). "Prebiotics in healthy infants and children for prevention of acute infectious diseases: a systematic review and meta-analysis.". Nutr Rev. 72 (8): 523–31. doi:10.1111/nure.12117. PMID 24903007.
- Macfarlane S, Macfarlane GT, Cummings JH (Sep 2006). "Review article: prebiotics in the gastrointestinal tract". Aliment Pharmacol Ther. 24 (5): 701–714. doi:10.1111/j.1365-2036.2006.03042.x. PMID 16918875.
- Guarner F (2005). "Inulin and oligofructose: impact on intestinal diseases and disorders". Br J Nutr. 93 (Suppl 1): S61–5. doi:10.1079/BJN20041345. PMID 15877897.
- Marteau P, Seksik P (2004). "Tolerance of probiotics and prebiotics". J Clin Gastroenterol. 38 (Suppl 6): S67–9. PMID 15220662.
- El Oufir L, Flourié B, Bruley des Varannes S, Barry JL, Cloarec D, Bornet F, Galmiche JP (Jun 1996). "Relations between transit time, fermentation products, and hydrogen consuming flora in healthy humans". Gut. 38 (6): 870–877. doi:10.1136/gut.38.6.870. PMC . PMID 8984026.
- Givson GR, Willems A, Reading S, Collins MD (1996). "Fermentation of non-digestible oligosaccharides by human colonic bacteria". Symposium 2. Proceedings of the Nutrition Society. 55: 899–912.
- Ritsema T, Smeekens SC (2003). "Engineering fructan metabolism in plants". J Plant Physiol. 160 (7): 811–820. doi:10.1078/0176-1617-01029. PMID 12940548.
- Weyens G, Ritsema T, Van Dun K, Meyer D, Lommel M, Lathouwers J, Rosquin I, Denys P, Tossens A, Nijs M, Turk S, Gerrits N, Bink S, Walraven B, Lefèbvre M, Smeekens S (2004). "Production of tailor-made fructans in sugar beet by expression of onion fructosyltransferase genes". Plant Biotechnol J. 2 (4): 321–327. doi:10.1111/j.1467-7652.2004.00074.x. PMID 17134393.
- Peppelenbosch MP, Ferreira CV (2009). "Immunology of pre- and probiotic supplementation". Br J Nutr. 101 (1): 2–4. doi:10.1017/S0007114508020746. PMID 18577301.
- Frank W. Jackson, "PREbiotics, not Probiotics". December 2, 2013, Jacksong GI Medical. ISBN 978-0991102709.