What are probiotics

What are probiotics?

Author – Spectrumceuticals Education, Research and Development

©Spectrumceuticals 2017 – This article, or parts thereof, may not be reproduced in any form without permission, except in the case of brief quotations embodied in critical articles and reviews.

The term ‘probiotic’ was first used by Lilley and Stillwell in 1965 to describe substances secreted by one microbe that stimulated the growth of another.

The friendly bacteria in our intestines comprise the beneficial types of bacteria found in the normal microflora of the human gut.

Humans have trillions of bacteria living in our intestines and there is increasing scientific research showing benefits of a balanced gut bacteria in health and wellness.


Probiotics are live microorganisms which, when administered in adequate amounts, confer a health benefit on the host.

World Health Organisation (WHO)


A group of scientific experts assembled in London in 2013, to discuss the scope and appropriate use of the term probiotic. The panel’s conclusions were published in June 2014 and can be summarised as;

Alive Organism

Probiotics have to be alive when administered. Concerns throughout the scientific literature resides in the;
viability and reproducibility on a large scale of the observed results, viability and stability during use and storage ability to survive in stomach acids and then in the intestinal ecosystem.


Documented Strains

Only products containing live organisms shown in reproducible human studies to confer a health benefit should be claimed to be a probiotic.

The correct claim of health benefit, with solid scientific evidence, should be the element for the proper identification and assessment of the effect of a probiotic.


Taxonomically Defined

Probiotics must be taxonomically defined microbes (genus, species, and strain level). It is commonly admitted that most effects of probiotics are strain-specific and cannot be extended to other probiotics of the same genus or species.



The 2002 WHO guidelines recommend that, though bacteria may be generally recognized as safe, the safety of the potential probiotic should be assessed by the minimum required tests:

  • determination of antibiotic resistance patterns
  • assessment of certain metabolic activities
  • assessment of side effects during human studies
  • epidemiological surveillance of adverse incidents


The beneficial bacteria are made up of hundreds of different species, the main two of which are Lactobacillus and Bifidobacteria.  These bacteria are found in the normal microflora of the intestine.



Lactobacillus is a type of bacteria. There are lots of different species of lactobacillus. These are ‘friendly’ bacteria that normally live in our digestive, urinary, and genital systems without causing disease. Lactobacillus is also in some fermented foods like yogurt and in dietary supplements



Bifidobacterium is a genus of bacteria ubiquitous inhabitants of the gastrointestinal tract, vagina and mouth of humans. Bifidobacteria are one of the major genera of bacteria that make up the colon flora in mammals. Some bifidobacteria are used as probiotics.