What are probiotics?


Primary Benefits

This includes the following primary benefits:

  1. Inhibition of bad bacteria (pathogenic) growth – Thus reducing the number effect of disease causing bacteria in the body.
  2. Maintenance of health promoting gut microflora – Probiotics help promote healthy ‘good bacteria’ in our gut
  3. Stimulation of immune system– Probiotics have immune stimulating properties that keep our immune systems healthy.
  4. Relieving constipation, absorption of calcium, synthesis of vitamins and antimicrobial agents, and pre-digestion of proteins[2] – Probiotics have a host of other health benefits and more are being discovered as more studies are carried out in this area.

Several health benefits have been proved for specific probiotic bacteria, and recommendations for probiotic use to promote health is increasingly becoming acceptable

Year after year, probiotics continue to gain popularity and increased use by clinicians based on evidence and perceived health benefits.

Brief definition and health benefits of probiotics

The term Probiotics is derived from Greek language meaning ‘ for life’ or literally translated ‘fit  for life’ This is in contrast with Antibiotics ( against life).

With increasing use and popularity among healthcare providers and population at large, many definitions have arisen with differing implications to their overall use.

According to WHO [1], Probiotics are defined as  live microorganisms which, when administered in adequate amounts, confer a significant health benefit on the host. This is probably the best and most commonly used definition, that is easy to understand and fully descriptive of the functions and benefits of probiotics.

Probiotics are commonly referred to as ‘ good bacteria’ – implying that they offer a positive and healthy benefit to the human body. This is in contrast to ‘ bad bacteria’ which are known to cause disease – Medically they are also called pathogens.

Intestinal flora  (Normal Flora) refers to the  harmless microorganisms such as bacteria, yeasts, and fungi that inhabit and grow in the intestines. These microorganisms are e ssential to the normal functioning of the digestive tract, and certain species of intestinal flora are beneficial to the human body.

Today it is widely recognized that a healthy balanced intestinal flora contributes to a large extent to our general wellness and health. The balance is key to both the digestive system and immune system for better natural defenses.

Small Intestine

The intestinal flora of the small intestine is comprised mainly of microorganisms known as  lactobacilli, which are a type of bacteria found in the digestive tract that produce lactic acid. “ Lactobacilli are one of the most important types of friendly bacteria found in the digestive tract. They play a key role in producing fermented foods, fermented milk, yogurt, and cheeses [and] are often referred to as “probiotic” since they are positive or supportive microorganisms.”(3)

Lactobacilli include bacteria such as Lactobacillus caseii, Lactobacillus bulgaricus, Lactobacillus acidophilus, and Lactobacillus helveticus just to name a few. Each of these types of bacteria provide various benefits to the human body. For example, Lactobacillus caseii (L. casei) “ exhibit[s] immune-enhancing effects by producing “bacteriocins”, [which are] compounds that restrict [the]growth of pathogens in the small intestine.”(3) Lactobacillus bulgaricus (L. bulgaricus) “aids [in the] digestion of dairy products, helps reduce cholesterol levels, breaks down complex proteins for easy assimilation, and alleviates acid reflux.”(3)

Large Intestine (Colon)

While lactobacilli can be found in the large intestine as well, one of the most “predominant species [that inhabit the large intestine is]...anaerobic lactic acid bacteria in the genus Bifidobacterium (Bifidobacterium bifidum)”(1)

“Lactobacilli and Bifidobacteria  maintain a healthy balance of intestinal flora by producing organic compounds. These organic compounds include lactic acid, hydrogen peroxide, and acetic acid that increase the acidity of the intestine and curb the reproduction of many harmful bacteria.”(4)

Furthermore, “Bifidobacterium bifidum has been used to  maintain or restore a normal, healthy condition in the intestines.”(5) The various type of Bifidobacterium include but are not limited to: Bifidobacterium adolescentis, Bifidobacterium breve, Bifidobacterium infantis, and Bifidobacterium longum. Each of these bacteria are beneficial to the human body as “bacteria in the human GI tract have been shown to produce vitamins and may otherwise contribute to nutrition and digestion.



  1. [1] FAO/WHO. Probiotics in Food.Health and Nutritional Properties and Guidelines for Evaluation, FAO Food and Nutrition Paper 85World Health Organization and Food and Agriculture Organization of the United Nations, Rome; 2006
  2. [2]  Rafter, 2003Probiotics and colon cancer. Best Pract. Res. Clin. Gastroenterology. 17849859

Other References:

  1. Todar, K. (2008). The Normal Bacterial Flora of Humans. Todar’s Online Textbook of Bacteriology. 
  2. Welter, S. (2007). Probiotcs: Friendly Bacteria, Keeping Your Intestinal Flora Healthy and Happy. Suite101.com. 
  3. Lactobacilli List, A List of the Key Lactobacilli (Friendly Bacteria) and Their Role in the Health of Your Digestive System. Published by NuFerm, Nutrition from Nature. 2006. 
  4. Learn the Benefits of Bifidobacterium. Published by VAXA International. Unknown.  
  5. Generic Name: Bifidobacterium Bifidum – Oral. Published by MedicineNet.com. 2005. 
  6. 6. Partial Characterization of Bifidobacterium Breve C50 Cell-Free Whey Compounds Inducing Modifications to the Intestinal Microflora. Journal of Dairy Science, American Dairy Science Association. 2002. 
  7. Probiotics. Published by DigestivesPlus.com. Unknown. 
  8. Effects of the Enteral Administration of Bifidobacterium Breve on Patients Undergoing Chemotherapy for Pediatric Malignancies. Published in Supportive Care in Cancer. 2009.  
  9. New Study Demonstrates That Bifantis™ (Bifidobacterium infantis 35624) Offers Relief for Women With Irritable Bowel Syndrome. Published in American Journal of Gastroenetrology, Medical News Today. 2006. 
  10. Bacteria Genomes – Bifidobacterium Longum, Bifidobacterium Longum Keeps the Human Digestive System Running Smoothly. European Bioinformatics Institute, European Molecular Biology Laboratory. 2009.  
  11. Lactobacillus Acidophilus. Published by Natural Standard Patient Monograph, MayoClinic.com. 2009.
  12. Narva, M. (2004). Effects of Lactobacillus Helveticus Fermented Milk and Milk-Derived Bioactive Peptides (CPP, IPP, and VPP) on Calcuim and Bone Metabolism. Institute of Biomedicine, Pharmacology. University of Helsinki.