Probiotics are live bacteria that are introduced to the body to cause a positive health effect. Within the body is a wide ranging and complex balance of bacteria that is vital to maintain good health, particularly in the digestive system. This bacterial ecosystem is important for proper immune function in preventing infection and warding off disease.

After birth, the bacterial ecosystem develops over the first 18 months – 2 years until fully colonised, with a balance between bad bacteria, that causes illness, and good bacteria that prevents illness. However, when the bacterial ecosystem becomes unbalanced in favour of the bad bacteria, infections can take hold and diseases can develop. This can happen either by an increase in bad bacteria, due to an invading pathogen, or by a reduction in good bacteria, such as if on antibiotics or during infancy. Probiotics aim to restore the balance of the bacterial ecosystem in the body and cause a positive health effect as a result.

In infants, caesarean section, premature birth or antibiotic use can all reduce the development of the normal bacterial ecosystem in the body, and probiotics can help increase the development. In healthy adults, the bacterial ecosystem is fully developed, and the main benefit of probiotics seems to be in enhancing the natural immune response to an invading body, and therefore help prevent infection. Probiotics may also be used in adults where the bacterial ecosystem has become imbalanced, such as with extensive antibiotic use or in old age.

There are many billions of different types of bacteria, and it has been shown that bacteria that are even of the same genus and species, but different strain, have very different effects. An effective probiotic product must therefore meet the following:

  • Must be live.
  • Produce a beneficial health effect.
  • State the specific strain of the type of probiotic used.
  • Use the same dosage levels in the product that were used in the supporting research that show the beneficial health effect that is claimed.

In the sections on the right you will find an extensive review of the current research and thinking on probiotics and their potential benefits. In the 'Probiotic Products' section you will find a review of the most common probiotic products around with world, with information on the strains used and current supporting research on their health effects. 


R. Harris
Bsc Physical Education, Sports Science and Physics, Loughborough University Founder

© 2010

Probiotics Home

Probiotic Products

What is a Probiotic?

Bacteria & the Body
Role of Bacteria in the Body
Bacteria & the Life Cycle
A Balanced Bacterial Ecosystem

Probiotics in the Body
How Do Probiotics Work?
Probiotics and Infants
Probiotics in Adults

Probiotics & Older Adults
What Sort of Probiotic?

What is the Best Strain?
Choosing a Bacteria Strain
When to Take Probiotics

Choosing a Product
Probiotic Delivery
Probiotic Uses