WHERE DO PROBIOTICS COME FROM?

At the time of the Roman Empire, average life expectancy was around 28 years, disease famine and war being the influential factors. More recently, approximately 100 years ago, 45 years would have been considered old. Throughout the centuries infant mortality has remained high. By the middle of the 20th Century life expectancy was estimated to be 3 score years and ten (70 years), and infant mortality had reduced significantly. However, it is interesting to note that the cause of death has changed. Heart disease is now by far the biggest killer in the western world. Cancer, in one form or another, is a close second.

Against these trends, scientists have identified communities living in several countries who survive up to, and in excess of 100 years of age. A significant discovery about these communities is that the incidence of heart disease and certain cancers is very low. Further investigation into this phenomenon has revealed certain similarities in diet.

The possibility that certain friendly, gram-positive bacteria may be used to treat enteric disturbances and also be effective prophylactics was first raised in the UK some 80 odd years ago by Loudon Douglas FRS, of Edinburgh, in his book 'The Bacillus of Long Life'. Douglas was reporting the work of the Russian bacteriologist Elie Metchnikoff, who was interested in the remarkable longevity of certain groups of Russian peasants. These groups appeared consistently to survive close to or beyond 100 years of age. Metchnikoff's research isolated one common factor - they all regularly consumed sour milk. When this phenomenon was investigated more closely it was discovered that sour milk contains colonies of bacteria of the Lactobacillicæ family. From this work on the lactobacillicæ, Douglas was led to wonder if this bacterium might also be useful in the treatment of enteric and associated conditions and the basis for modern probiotic research was thus laid .

At that time, little attention was paid to his findings. However, in recent years, much work has been carried out in the search for a credible, more natural alternative to antibiotic drugs. For example, the Finnish National Veterinary Institute's pioneering work with poultry, on what has become known as 'Competitive Exclusion', showed that young chicks obtain friendly bacteria from their mothers. These colonise their own intestines thereby preventing potentially pathogenic bacteria from multiplying, colonising the gut and causing death early in life. These friendly life-supporting bacteria turn out to be members of the Lactobacillicæ genus.

So, although the probiotic idea has been around for over a century, little still seems to be known about what exactly is meant by the term, and thus of what a probiotic is and what it does. One reason for this is that, until recently, little information has been generally available. However, there is mounting public awareness of human health issues and a growing desire for reliable, safe, more natural alternative prophylactics and treatments. Credible probiotics are increasingly being used, in many cases, more successfully than drugs in the treatment of enteric and related diseases.

WHAT IS A PROBIOTIC?

The term 'probiotic' , strictly speaking, can be applied to any substance that supports life - water and oxygen are obvious examples. However, for present, more focused, health promoting purposes, 'probiotic' is universally accepted as describing preparations containing beneficial bacteria, mostly from the family Lactobacillicæ including Enterococcus, Bifido and Lactobacillus acidophylus itself. These lactic acid-producing, beneficial, non-pathogenic micro-organisms are ubiquitous in nature and are responsible for cheese and yoghurt fermentation as well as being found in plant material and even saliva. The gastro-intestinal tracts of humans, animals and birds maintain a delicate balance between these beneficial bacteria and the potentially pathogenic organisms, which are known to produce, for example, food contamination, such as the Protozoa, Algæ, Yeasts and Moulds and of course, the gram-negative bacteria species like salmonella.

HOW DOES A PROBIOTIC WORK?

For a probiotic to work, viable cells of the beneficial, lactic acid-producing bacteria, must be present (and ingested) in sufficiently large numbers to rapidly colonise and protect the gut environment and they must also be able to withstand a broad range of pH conditions, ie. changes in the acid alkali balance, whilst being able to multiply at at least the same rate as their pathogenic competitors.

Research has shown that the Enterococcus fæcium bacterium fulfils this requirement more effectively than any other known friendly bacteria to date.

PROBIOTICS - WHERE CAN THEY BE USED?

It is important to understand how a probiotic may be used to good effect. Firstly, no probiotic can ever fully replace antibiotics - it cannot be used to treat many clinical illnesses and, up until recently, was presumed only to be effective in the gut. However, there are a number of conditions in which a properly formulated, viable probiotic product has been shown to be of considerable benefit. For example:

• COLITIS / IRRITABLE BOWEL SYNDROME (IBS)
  
  Research at Tufts University School of Medicine has shown that the administration of a probiotic can be effective in controlling Colitis (Gorbach et al. 1989, p. 1519). Probiotics are also very effective in speeding recovery following diarrhoea - see below.

• CANCER
  
  Current medical research into the links between cancer and nitrosamines, which are formed biochemically through the combination of nitrites, from ingested food, with other substances, is showing promise. Recent research (Preston-Martin et al. 1982) indicates that regular ingestion of foods containing nitrites increases the risk of cancer, especially of the colon. Although more work is needed, researchers are convinced that by introducing gram-positive bacteria of the Lactobacillicæ family into the digestive tract, harmful bacteria are deterred from multiplying and thus making the enzymes that produce nitrosamines.

• CYSTITIS
  
  In the treatment of Cystitis, (the result of Escherichia coli proliferation in the bladder - but not interstitial Cystitis), administration of an effective probiotic:
  
  (i) normalises the gut environment, by 'closing the door' on E. Coli proliferation,
  
  (ii) aids the reduction of inflammation of the bladder by removal of the antagonists and, at the same time, by increasing fluid intake, increases the uptake of electrolytes which are a necessary component of a balanced probiotic formula.

• INAPPETENCE AND EATING DISORDERS
  
  The adverse effects of digestive disturbances are well known. They have been the subject of numerous investigations by some of the most respected scientists and nutritionists. Inappetence, when it occurs, will obviously require investigation. However, a proven probiotic will introduce, and consequently increase, gram-positive friendly microbial activity, which, with improved nutrient absorption, also stimulates appetite. This coincides with findings from the Agricultural Research Institute, at Hurley, where duodenal infusion of lactic acid has been shown to stimulate appetite.
  
  Just as important is the proper investigation of eating disorders such as anorexia nervosa and bulimia. Where subjects with these types of disorder are psychologically disposed to face up to, and recover from, any such problem, current research would suggest that a balanced probiotic has much to offer to support them on their road to recovery.

• SKIN CONDITION
  
  Poor skin condition is frequently the result of a digestive disorder caused by ingested antagonists or inadequacies of diet. Attention to a proper diet and the regular administration of an effective probiotic, in conjunction with high dose Vitamin C therapy, will, in many cases, alleviate the condition, and in others eliminate it completely. Psychological stress may also be a factor worth consideration, in such cases.

• DIARRHOEA/DEHYDRATION
  
  Dehydration from diarrhoea may, in severe cases, result in heart failure. Therefore, the primary consideration is to stabilise the circulatory system by providing fluid and replacing lost electrolytes. This achieved, the second phase is to re-acidify the gut, thus creating an ideal environment for the friendly bacteria, but one which is, at the same time, antagonistic to pathogenic bacteria.
  
  During diarrhoea, the action of a viable probiotic, therefore, is to introduce viable cells of friendly bacteria :
  
  (a) to colonise the gut thereby rapidly re-acidifying the environment and slowing down multiplication of acid-sensitive pathogens
  
  (b) that are strong enough to withstand the poor gut environment, multiply and compete with pathogens for nutrients.
  
  (c) which, by adhering to the villi, compete for 'attachment' sites and nutrients, otherwise known as 'Competitive Exclusion'
  
  It is also believed that during a bout of diarrhoea, substantial losses of nutrients will occur and thus they will require to be replaced quickly and effectively. A properly formulated probiotic will fulfill all of these critical requirements.

• STRESS
  
  A variety of situations can create 'stress' (more correctly described as dis-tress) - whether metabolic, physiological or psychological - which results in changes in the gut environment, thus favouring the pathogenic micro-organisms. Multiplication of these pathogens will result in toxins being produced that are both antagonistic to Lactobacillicæ species and thus to the person. Again, diarrhoea is a case in point, which, if left untreated may ultimately lead to serious dehydration and subsequent death. This is of particular significance to travellers and of course, to those living in the developing world where in many instances hygiene and environmental conditions are less than ideal.