Prebiotics, Probiotics, Synbiotics, Psychobiotics

Prebiotics, Probiotics, Synbiotics, Psychobiotics are not similar but they are related to microorganisms. However, these terms Prebiotics, Probiotics, Synbiotics, Psychobiotics are discussed one by one.


Generally, prebiotics are non-digestible food ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of bacterial species already established in the colon, and thus in effect improve host health. Simply, prebiotics are the nutritional sources of probiotics.

In 1995, Marcel Roberfroid identified and named this term [1]. Prebiotics undergo fermentation by probiotics in the large intestine and they are the sources of energy for probiotics. Prebiotics must also meet the following criteria [2]:

  1. Non-digestible
  2. Resistant to breakdown by stomach acid and enzymes in the human GI tract.
  3. Selectively fermented by intestinal microorganisms.
  4. Selectively target and stimulate the growth and activity of beneficial bacteria.
Examples of Prebiotics are:


According to the World Health Organization, probiotics are live microorganisms that when administered in adequate amounts confer a health benefit on the host [3]. Etymologically, the word probiotic appears to be a composite of the Latin preposition pro (“for” or “in support”) and the Greek adjective (biotic) from the noun bios (“life”) meaning ‘for life’ or ‘in support of life’ [4].

In 1907, Russian-born Nobel laureate Elie Metchnikoff, known as the “father of probiotics, suggested that “The dependence of the intestinal microbes on the food makes it possible to adopt measures to modify the flora in our bodies and to replace the harmful microbes by useful microbes” [5].

Examples of prebiotics are:
  • Lactobacillus acidophilus,
  • Lactococcus lactis,
  • Enterococcus faecalis, and
  • Saccharomyces boulardii.

If you want to know more about probiotics, you may read: What are Probiotics? Example, Criteria and Common Mechanism


Synbiotics are the mixtures of probiotics and prebiotics that beneficially affect the host by improving the survival and implantation of live microbial dietary supplements in the gastrointestinal tract of the host [6]. So, the synergistic combination of pro- and prebiotics is called “synbiotic”.

Examples of synbiotics are:
  • The mixture of Lactobacillus acidophilus and Fructooligosaccharides (FOS) is called synbiotics.

Other examples of synbiotics are:

  • Lactobacillus rhamnosus GG and inulins, and
  • Bifidobacteria or Lactobacilli with FOS or inulins or galactooligosaccharides (GOS).


Psychobiotics are live bacteria (probiotics) which, when ingested in adequate amounts, confer mental health benefits through interactions with commensal gut bacteria [7]. Basically, psychobiotics exert its mechanisms by influencing bacteria–brain communication channels. Psychobiotics exert anxiolytic and anti-depressant effects characterized by alterations in systemic, cognitive, emotional, and neural indices.

Examples of some psychobiotics are [8, 9]:
  • Lactobacillus helveticus
  • Bifidobacterium longum
  • Lactobacillus casei
  • Bifidobacterium breve
  • Lactobacillus plantarum
  • Bifidobacterium infantis
  • Lactobacillus acidophilus
  • Streptococcus salivarius
  • Lactobacillus rhamnosus
  • Lactobacillus gasseri

You may also read:

  1. What are Probiotics? Example, Criteria and Common Mechanism
  2. Incredible 16 Health Benefits of Probiotics and Natural Sources



1. Gibson GR, Roberfroid MB (1995). Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. J. Nutr. 125(6), 1401–1412
2. Slavin, Joanne (2013). “Fiber and Prebiotics: Mechanisms and Health Benefits”. Nutrients. 5 (4), 1417–1435
3. Food and Agriculture Organization and World Health Organization Expert Consultation. Evaluation of health and nutritional properties of powder milk and live lactic acid bacteria. Córdoba, Argentina: Food and Agriculture Organization of the United Nations and World Health Organization; 2001. [cited 2005 September 8]
4. Hamilton-Miller JM, Gibson GR, Bruck W (2003). Some insights into the derivation and early uses of the word ‘probiotic’. Br. J. Nutr, 90 (4), 845
5. Metchnikoff E (1907). Lactic acid as inhibiting intestinal putrefaction. In: The prolongation of life: Optimistic studies. W. Heinemann, London: 161-183
6. Andersson H, Asp N-G, Bruce A, Roos S, Wadstrom T, Wold AE (2001). Health effects of probiotics and prebiotics: A literature review on human studies. Scand J Nutr, 45, 58-75
7. Sarkar A, Lehto SM, Harty S, Dinan TG, Cryan JF, Burnet PW (November 2016). “Psychobiotics and the Manipulation of Bacteria-Gut-Brain Signals”. Trends in Neurosciences. 39 (11): 763–781
8. Bambury A, Sandhu K, Cryan JF, Dinan TG (December 2018). “Finding the needle in the haystack: systematic identification of psychobiotics”. British Journal of Pharmacology. 175 (24): 4430–4438
9. Dinan TG, Stanton C, Cryan JF (November 2013). “Psychobiotics: a novel class of psychotropic”. Biological Psychiatry. 74 (10): 720–6