‘Good’ Bacteria or Probiotics
The World Health Organization and the Food and Agriculture Organization of the United Nations define probiotics as "live microorganisms, which, when administered in adequate amounts, confer a health benefit on the host."
Probiotics are available as dietary supplements in the form of pills, capsules and powders for example, and also in certain foods. Recently, they have come to be added to a range of foods. They exist naturally in some foods. Probiotics are, in particular, abundant in in fermented foods. Interestingly, most Candida diets recommend banning fermented foods, which seems a bit odd to me.
Most probiotics are similar to the naturally occurring bacteria found normally in the gut.
Very many species of bacteria, yeast and other organisms inhabit the gastrointestinal tract of every human. These are known as the ‘gut flora’. In an average adult, the total weight of the bacteria is an amazing 1 Kg.
There are actually more individual bacteria than there are cells in the human body. Most of these bacteria and not harmful to health and many of them, the ‘friendly bacteria’, which we have become familiar with from numerous television commercials for yoghurt, are thought to help keep the human body functioning properly in a well balanced way.
The strains of these ‘friendly bacteria’ familiar to us from the media are lactobacillus and bifidobacterium. These have been shown to inhibit pathogenic bacteria such as Salmonella and H Pylori (the ulcer causing bacteria) and other things, while leaving other organisms unharmed.
There is nothing new in using probiotics, apart from the name. Humans have been using probiotics throughout history. People in Biblical times drank sour milk to help cure bowel problems, for example. Bulgarians developed the system of preserving milk (removing the lactose and predigesting the proteins) and transforming it into yogurt and cheese.
The fermentation of foods has been used for centuries as a way of preserving them, for example fermented beans, pickles, sauerkraut and kefir. Fermented foods contain large amounts of probiotics or ‘friendly bacteria’.
No one is really sure exactly how probiotics or ‘friendly bacteria’ work but it is reckoned that once in the intestines they help to maintain a balanced environment with other bacteria found in the gut, assist in digestion, synthesise vitamins and interact positively with hormones.
Imbalance in the gut flora, as we have seen can result in certain organisms, such as Candida and/or pathogenic bacteria taking over, with dire health consequences for the host.
Gut Flora Imbalance
One primary cause of imbalance in the gut flora, as we have seen, is from antibiotic use, though other causes also can contribute to this imbalance. <See Risk Factors> Probiotics are thought to counteract this imbalance and work to restore the proper size of the naturally occurring populations of yeasts, bacteria and other organisms to the benefit of the host.
A large number of popular health claims are made for probiotics:-
- Preventing gastrointestinal cancer
- Supporting the immune system
- Reducing lactose intolerance
- Reducing asthma and eczema
- Fighting Infectious diarrhoea
- Alleviating Irritable bowel syndrome
- Alleviating Inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease)
- Preventing Infection with Helicobacter pylori (H. pylori), a bacterium that causes most ulcers and many types of chronic stomach inflammation
- Alleviating tooth decay and periodontal disease
- Fighting vaginal infections
- Alleviating skin infections
Scientists are interested in probiotics in particular, because there are cells within the intestinal tract concerned with the immune system. One theory is that the introduction of ‘good bacteria’ can strengthen the immune system.
The most encouraging scientific evidence for the therapeutic benefits of using probiotics is in the treatment of chronic diarrhoea, C- Difficile, irritable bowel Syndrome and eczema. As yet, the scientific evidence is quite limited and much more research is needed, but there is already a growing body of persuasive evidence that probiotics have much potential in clinical situations.
Current research interest is currently focused on:-
- the ability of probiotics to treat and prevent disease
- how best to take them – ie in food or as a nutritional supplement, and in what doses for therapeutic purposes
- What happens to probiotics when they are ‘treated in some way, ie added to foods or used in capsules etc
- Whether they have a role to play in the problem of antibiotic resistant bacteria in the gut
Probiotics taken as a dietary supplement are produced and regulated as foods not medicines.
References
- An Introduction to Probiotics [NCCAM Health Information]
- Fermentation is Fun: How to get started with Fermented Foods at Home.
- Probiotics, unpacked — Friendly bacteria are good for you :: by Catherine Bennett Dunster :: Culinate
- Alvarez-Olmos MI, Oberhelman RA. Probiotic agents and infectious diseases: a modern perspective on a traditional therapy. Clinical Infectious Diseases. 2001;32(11):1567–1576.
- Gill HS, Guarner F. Probiotics and human health: a clinical perspective. Postgraduate Medical Journal. 2004;80(947):516–526.