Probiotics and prebiotics each have their own role to play in the battle for better gut health.

But to clear things up, here’s a handy guide for each term:

  • Probiotics: These are living strains of bacteria that add to the population of good bacteria in digestive system.
  • Prebiotics: Specialized plant fibre that acts as food for the good bacteria. This stimulates growth among the pre-existing good bacteria.
  • Synbiotics:
  1. A probiotic organism in combination with its prebiotic food is defined as a synbiotic.
  2. Providing both the organism and substrate at the time of ingestion may offer improved chance of survival in GI tract.
  3. The efficacy of a symbiosis can be contributed to improvement in probiotic viability and imparting specific health benefits.
  4. Synbiotic food consumption predominantly aids in enriching health benefits by stimulation of gut metabolism and maintenance of gut physiological features.
  5. The health benefits derived from a synbiotic supplementation is mainly due to elevation in Short chain fatty acids (SCFA), ketones, carbon disulphide and Methyl acetate.


Most of us think bacteria as harmful organisms. However, this may not be the case always. Many of them are highly beneficial for our health.

  • Probiotics are nutritional supplements;
  • They contain one or more cultures of living organisms and these micro-organisms are typically bacteria or yeast;
  • These probiotics are able to modify the endogenous micro-flora and they have a positive effect on the host.

▶ History of use of Probiotics

The history of uses of probiotics has been kept hidden long back in the past, but the systematic study of probiotics has not been for so long and is discussed in the table given below:

Table 1

▶ Functions of Probiotics

Health benefits for humans from probiotics include the following:

o Elimination of lactose intolerance.
o Anti-diarrheal
o Immunomodulatory
o Antidiabetic
o Anti-carcinogenic
o Hypocholestrolemic
o Antihypertensive

▶ Factors to be considered for probiotics selection:

  • Acid Tolerance: The strain which has the ability to survive in host conditions vary considerably and these are required to be taken into consideration while cultivating, storing and transporting the microbial strain for human consumption.
  • Human Gastric Juice Tolerance: Microbial potential to tolerate the gastrointestinal acidity and bile stress needs to be taken into prime consideration while selecting a particular strain from commercial sources and to ensure the positive health effects of the probiotics. For a probiotic microorganism to impact the organ environment, a desirable population of 10^6 to 10^8 cfu g-1 of intestinal contents has been determined.
  • Bile Tolerance: Probiotic ability to hydrolyze bile salts has been found to be another relevant parameter for strain survival in host.
  • Adherence to Epithelial Cell Surface: Epithelial adhesion prevents probiotic elimination by peristalsis. Epithelial adhesion property of probiotic strains has been attributed to auto-aggregation property, proteinaceous nature of surface components and presence of Surface Layer Proteins (SLPs).
  • Immune-Stimulatory but not Proinflammatory Effect: Immunoregulation by probiotics can be contributed to enhancement in non-immunologic gut defence barrier which comprises of reduction in elevated intestinal permeability and normalization of altered gut microfloral ecology.
  • Antagonistic Activity against Pathogens: Probiotics elevate host defense mechanisms by enhancing non-specific host resistance to invasive microbial pathogens and altered gut micro floral stabilization.

▶ Major examples of Probiotics and their unique features:

  • Lactobacillus acidophilus: It shows several benefits like stabilization of intestinal microflora, preventing colonization of enteropathogenic bacteria by competing for intestinal wall adhesion, reduction of lactose intolerance, prevention of lactose induced diarrhea and colon cancer, immunostimulation, etc. selection: unique features:
  • Lactobacillus rhamnosus GG: It is indicated in prevention and treatment of gastrointestinal infections, diarrhoea and vaccine potentiation by immune stimulation and anti-allergic effects.
  • Lactobacillus casei Shirota (LcS): It stimulates immune responses by promotion of phagocytosis and enhancement of natural killer cell cytotoxicity.
  • Lactobacillus plantarum: It has been mainly associated for its antimicrobial activity in female urogenital infections.
  • Lactobacillus reuteri: It is preferred as a probiotic for its antimicrobial properties.
  • Bifidobacteria sp.: It catalyzes fermentation reaction in colon resulting in production of Short Chain Fatty Acids (SCFAs) like acetate, propionate and butyrate. They also aid to synthesize vitamins like Vitamin B and have antimicrobial properties as well.


Prebiotics are:

  • Non-digestible food supplements or ingredients
  • Not absorbed or degraded
  • Positively affect the endogenous flora
  • Stimulate the growth of one or a limited number of bacterial species.
  • Prebiotics are obtained from fruits, vegetables, dietary fibres present in polysaccharides like starch by various processing steps like extraction, concentration, hydrolysis or enzymatic modulation.

▶ Prebiotic Supplementation & Human Health

  • Effect on Gut                                                                                                                                The prebiotic supplementation led to enhancement in concentration of beneficial bacteria and decrease in hazardous or less desirable microbes.

▶ Host health and physiology

  • Promotion of Bacterial Fermentation: They potentiate activity of beneficial microbiomes in human gut and reduce metabolic activity of hazardous bacteria by alleviating the bacteria by various mechanisms.
  • Dietary Substrate Utilization: Human diet comprising of non-digestible oligosaccharides, fibres, proteins, etc. acts as growth substrates for gut microflora. Main growth substrates comprise of non-digestible carbohydrates like resistant starch, dietary fibres, resistant dextrins, Non Starch Polysaccharides like pectins, gum Arabic, guar gum and hemicelluloses, etc.

▶ Beneficial Metabolite producing activities

Intestinal microbiota metabolize consumed prebiotics to produce metabolism products like acetate, propionate, butyrates, lactates, pyruvates, ethanol, succinate and gases like hydrogen, carbon dioxide, methane and hydrogen sulphide.

▶ Types of Prebiotics

 Fructans
Fructans pass through the upper GIT without metabolism reaching the colon. In colon, they are fermented to SCFAs by colonic microflora.

 Inulin
Inulin is found in leeks, onions, wheat, asparagus, garlic and chicory. Inulin has been demonstrated to promote digestive health, lipid metabolism, lowering of insulin and triglycerides levels, increase calcium absorption thus decreasing osteoporosis and reducing risks of cancerous activity in colon and breast.

 Fructo-oligosaccharides (FOS)
Fructo-oligosaccharides are commonly found in plants like Asparagus, wheat, Jerusalem chokes, rye and onion. In colon, FOS is metabolized by fermentation to lactate, SCFAs (acetate, propionate and butyrate) and gas.

 Lactulose
Lactulose causes increase in Lactobacilli and Bifidobacterial colony counts and a decrease in bacteroidal concentration.

 Galacto-Oligosaccharides (GOS)
Galacto-oligosaccharides stimulate the growth of Bifidobacterium species, improve calcium absorption, provide relief from constipation, stimulate human immune system, and prevent colonic cancer.

Therefore, since probiotics and prebiotics offer a wide range of benefits, they can be added to your diet as part of your daily meal. Rather than adding supplements, probiotics and prebiotics, if consumed in their natural form can be highly beneficial for your body.


  1. Akdis, M, Frei, R., OMahony, L, 2015 Prebiotics, probiotics, synbiotics, and the immune system. Curr Opin Gastroenterol, 31(2):153-158.
  2. Akkermans, L. M., Haller, D., Sanders, M. E., 2010. Safety assessment of probiotics for human use. Gut Microbes, 1(3):164-185.
  3. Ali, F. S., Hussein, S. A., Saad, O. A. O., 2013. Antimicrobial activity of probiotic bacteria, Egypt. Acad. J. Biolog. Sci., 5(2): 21-34.
  4. Amiot, J., 2008. Immunomodulatory Effects of Probiotics in the Intestinal Tract, Curr. Issues Mol. Biol. 10(1-2): 37-54.
  5. Angelakis, E., Merhej, V., Raoult, D., 2013. Related actions of probiotics and antibiotics on gut microbiota and weight modification. The Lancet, Infectious Disease, 13(10) 889-899.
  6. Arvilommi, H., 2001. Probiotics: effects on immunity. Am J Clin Nutr, 73 (2): 444-450.
  7. Aryana, K. J., Mena, B., 2012. Influence of Ethanol on Probiotic and Culture Bacteria Lactobacillus bulgaricus and Streptococcus thermophilus within a Therapeutic Product, Open Journal of Medical Microbiology, 2:70-76.
  8. Barlow, J., Costabile, A., Gibson, G. R., Rowland, I., Tejero-Sarinena, S., 2012. In vitro evaluation of the antimicrobial activity of a range of probiotics against pathogens: Evidence for the effects of organic acids. Anaerobe, 18(5):530-538.

About the Authors:



The views/opinions expressed by authors on this website solely reflect the author(s) and do not necessarily reflect the views/opinions of the Editors/Publisher. Neither the Editors nor the Publisher can be held responsible and liable for consequences that may arise on account of errors/omissions appearing in the Articles/Opinions.


An editor by day & dreamer at night; passionately involved with both print and digital media; Pet lover; Solo traveller.

Write A Comment

5 + 7 =