PROBIOTICS, A SCIENTIFIC OVERVIEW.

There is good and bad in everything and the microscopic world of bacteria is no exception. There are good and bad bacteria and huge differences in their effect on other forms of life, humans, animals and other forms of organic matter. Some forms of bacteria are responsible for causing disease and possible death, these are called pathogenic micro-organisms (potentially disease producing bacteria) while others protect or at least support life, commonly termed friendly bacteria or probiotic bacteria, (Pro = for and biosis = life).

For the purpose of this article, we can group the friendly bacteria and call them good bacteria and the pathogens, bad bacteria, this will make it easier to understand when referring to the variety of species within each group (group = genus). As a simple example we can use humans (Genus homosapien) - and the numerous species within the group.

For example, I am human but Welsh! (no rugby jokes please!). One reader may be Turkish, and another Brazilian, We are all humans, yet we have subtle differences. The animal world is similar and so too is the microscopic world of bacteria. Particular bacterium may belong to a specific group, however, within the group there may well be a number of species. This is a very simplified example, but it illustrates the point.

To illustrate this further it will help us to understand why environment is so important. Take an individual like me as an example. It is highly likely that my ancestors came from the Nordic people (Nord = North) I have blonde hair and blue eyes. Contrast this with a person from Nigeria, dark skin, brown eyes and black hair. The one dominant factor that has made us different, is environment. For example, the Nigerian is quite acclimatised to the high temperatures, put me there and I’ll fry! Too much heat is very distressing for most fair people. The modern Nigerian’s ancestors developed protection from the damaging effects of the sun by darkened skin. S/he has adapted to environment just as my ancestors became acclimatised to the very cold environment of the icy north. Bacteria are not really any different, they have an ideal environment and yet other environments may be very distressing or even fatal to them.

Bacteria can be further identified by several means - their shape is just one example, i.e. Coccus = Spherical. Bacillus = Rod-like…. Bacteria can be also be categorised by its ideal environment, i.e. anaerobic or aerobic. Anaerobic bacteria can be very sensitive to oxygen and may not survive in an environment with only a tiny concentration of oxygen. Aerobic bacteria however, are oxygen loving and like us, rely on it for survival. We can go further still and identify a specific bacterium to certain conditions for example, "Enterobacterium" normally inhabit and affect the gut. "Mycobacterium" are associated with respiratory conditions.

In an attempt to survive, some bacteria have evolved to be able to produce substances that they excrete to create or sustain an ideal environment for themselves. Lactobacillus, (good bacteria) for example, produce an acidic substance. Bad bacteria such as variants of Escherichia coli. on the other hand will produce toxins. Enterotoxigenic E. coli. is one of a number of bacteria species responsible for causing diarrhoea under certain conditions.

Environment therefore, is one major influential factor that must be taken seriously when using a probiotic either in prophylaxis (prophylaxis = disease prevention) or treatment. However, (there is always a however!) speed of growth (regeneration time) is just as critical as this article illustrates later. Furthermore, I believe regeneration time is critical in both enteric treatment and prevention of disease.

Speed of regeneration can be better understood by illustrating another situation that we can more easily relate to. Imagine you are the Commanding Officer of an airforce and you are at war (fighting bad bacteria is a war for life!) your factories are able to make one new aircraft per hour but, your enemy is able to produce 3 aircraft hour! Therefore your enemy is able to make three aircraft in the same time as it takes for your factories to make just one. It is obvious that this may very well place you in a most vulnerable situation and therefore, there is a strong possibility that you will become overwhelmed by the enemy and unlikely to withstand and overcome the onslaught from the them. When you give a probiotic that can only produce one good bug in the same time it takes the enemy to produce 3 bad bacteria you will have the same problem as the Airforce Commander.

Now relate the above example to Salmonella, very dangerous bad bacteria, and (Lactobacillus acidophylus, L A), good bacteria. Salmonella are capable of doubling in number, every 20 minutes. L A is very much slower and realistically may double in number only once per hour. Furthermore, L A will need an acidic environment to do so! LA is notoriously unstable and very intolerant of changes in environment. Therefore, we can say with some certainty that LA is of little use to protect against the affects of bad bacteria or in the treatment of a digestive system disturbance. It is fair to say however, that in a healthy recipient, L A may contribute to the maintenance of an already healthy digestive system.

There are a number of other good bacteria that also come into the category of unreliable and relatively ineffective, L. casei, for example. These bacteria are normally associated with the fermenting process of cheese and yoghurt making. Recently a glut of cultures containing drinks for humans has arrived with names designed to impress the potential buyer. In reality however, the bacteria used in these products have little beneficial effect as a probiotic. They are too slow to grow and too unreliable.


So, what should you look for? Firstly, learn the language! And read the label carefully.

Avoid products that claim that they contain:-


Species specific (these may contain a questionable mixture of bacteria)

Live bacteria - XXXX number of species (sometimes 5 or 7 species …) of friendly bacteria (again, a questionable mixture)

Freeze-dried bacteria


Let’s examine these claims a little closer:

Species specific : the producer is claiming that they are capable of fermenting a precise mixture of bacteria. This is nothing short of an insult to anyone of even average intelligence! Give these brands, and anything else the company making this claim produces, a very wide berth indeed.

Live Bacteria : This tongue-in-cheek statement is very deceiving and in my view may contravene the Trades Description Act. It is however, deliberately intended to manipulate the mind of the buyer in favour of their product. If the bacteria were live, and live means metabolising, the shelf life of the product could not be more than a day or two! What they really mean is that the product contains bacteria that should be "viable" and able to metabolise when rehydrated. The ethical or correct word here is "Viable" not "live"! Again you may wish to question the ethics of the firm(s) making such claims. Some liquid probiotics may contain metabolising bacteria. However, their shelf life is very short and if not stored in a refrigerator the product will be spent out very quickly and as a result of the bacteria activity, the bottles have become ‘blown’ because of the pressure build up. Not very satisfactory at all!

X number of species of friendly bacteria : This is playing the numbers game. The fact that a probiotic may contain 2, 5 or 7 species of friendly bacteria is meaningless and in reality amounts to very little benefit! Most of the friendly bacteria in these products are unreliable and very unstable. Therefore, may not be able to metabolise. Furthermore, out of the 5 or 7 species two may be of some use and in my view, only one is reliable. Another very important factor that will influence the number of bacteria able to grow is the method used to render the bacteria dormant, i.e. into suspended animation, (see freeze drying).

This numbers game should not be confused with a legitimate CFU declaration guarantee (cfu = colony forming units). This is the correct method of declaring the number of viable bacteria in the product, i.e. "Contains 4.5 billion cells, or Colony forming units of xyz bacteria per gram of product"

Freeze Dried : This is the most common, least costly method of putting the bacteria into suspended animation. However, it is also well known that freeze drying damages and will even destroy the bacteria. Therefore, the number of viable bacteria in the product may be much lower that the number declared on the label. It is also worth keeping in mind that for a probiotic to be effective the bacteria must grow into billions very quickly! Growth merely in the millions is not ideal in relation to a probiotic’s effectiveness. Disease-producing bacteria are capable of growing in number into billions within a few hours in the right conditions. To illustrate just how quickly Salmonella can grow, It has been said that one single cell of Salmonella is capable of starting a chain of events that could lead to the production of a mass of bacteria that would be bigger than the size of the earth within 24 hours, if all the bacteria formed in the regeneration process survived!

Referring to the drying of the bacteria to put them in to suspended animation, there are other more desirable gentler methods, thus reducing the potential of damage from freeze drying! Note please that a number of firms selling probiotics claim, on their label, that the bacteria in their product are freeze-dried! About two years ago a well know firm who was marketing a liquid probiotic, publicly criticised freeze dried products – now they openly sell a freeze dried probiotic!

Previous independent tests on a number of probiotic products indicated that the number of bacteria that were capable of growing were much less that claimed on the product’s label. Vydex's probiotics produce bacteria in the billions, which is the amount needed to effectively combat bad bacteria.

Copyright: Melvyn John. M. Inst. Comp Med. Dip Psychol.