Probiotics – friendly bacteria?
The normal human digestive tract contains hundreds of different types of bacteria that compete with and reduce the growth of potentially harmful microorganisms. You carry around 1.5 kg of bacteria inside you, approximately the same weight as your liver, and they have a big metabolic effect on your body. Probiotics are microorganisms which are believed to help maintain the natural balance of organisms (microflora) in the body, so they are sometimes called “friendly bacteria” (particularly by friendly marketing executives). The largest group of probiotic bacteria in the intestine are Bifidobacteria and Lactobacilli, of which Lactobacillus acidophilus, found in yogurt, is the best known. Yeast is also a probiotic substance.
Prebiotics are non-digestible oligosaccharides that support the growth of certain bacteria in the colon. The idea is that rather than consuming the friendly bacteria directly, you grow your own. However, the science behind most prebiotics supplements is decidedly dodgy, with very little evidence that they are actually effective (Prebiotics: the concept revisited. J Nutr. 2007 137(3 S2): 830S-837S).
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Research has shown that probiotics may help reduce symptoms of bloating and diarrhoea from lactose intolerance (Protection from gastrointestinal diseases with the use of probiotics. 2001 American Journal of Clinical Nutrition, 73(2, S1): 430S-436S). More controversial claims include the role of probiotic bacteria in preventing inflammatory bowel disease (IBD), which causes diarrhoea and abdominal pain, and colon cancer.
Probiotics are available as dietary supplements as well as so-called “functional foods” such as yoghurt and drinks. The market for these products is booming – in the first four months of 2005, 200 new products were launched in the UK alone. Probiotics are big business, with the global market for functional foods in 1994 was US$6.6 billion, with Japan accounting for nearly one-half of the total. The worldwide market was believed to have reached US$17 billion by 2000, with the long-term potential to become as big as the low-fat and low-calorie markets, in excess of US$87 billion (Market potential for probiotics. Am J Clin Nutr. 2001 73(2S): 476S-483S).
The U.S. Food and Drug Administration (FDA) and the UK Food Standards Agency (FSA) do not regulate dietary supplements such as “functional foods” in the same way that medicines are controlled. A dietary supplement can be sold with little or no research on its safety, or even whether it has any beneficial effect (Functional foods: the case for closer evaluation. BMJ. 2007 334: 1037-1039). Very little is known about the long term effects of these foods, and whether functional foods might interfere with drugs prescribed by doctors. Tim Lang, professor of food policy at City University in London, says that “functional foods are at best a technical fix, masking an underlying poor diet – and they make it harder for nutrition experts to work out the effects of good and bad diets” (BBC: Functional foods prompt warning).
There’s no magic shortcut to good health and no substitute for exercise and a healthy diet.
History of Probiotics
Probiotics in the form of substances containing lactobacillus, acidophilus and Bifidobacterium cultures have been used for centuries as food preservatives and natural sources to promote good human health without specific knowledge of their active ingredients or how they work. Lactobacillus was first identified by Pasteur (1845 – 1895) in France, the pioneer of modern microbiology. A real understanding of how probiotics function began when the Nobel Prize winning Russian physiologist, Metchnikoff (1845 – 1916), introduced his intoxication theory. He stated that the main cause of aging is “toxicants” formed by intestinal putrefaction and fermentation and suggested drinking beverages such as yogurt containing lactic acid bacteria would prevent aging. Lactobacilli suddenly attracted world attention.
People have also believed in witchcraft for centuries without specific knowledge of how it works. It’s interesting that your company is involved in selling probiotic products!
[...] Probiotics – friendly bacteria? [...]
Hi,Dr Alan Cann:
I just found your website today and it is really good. I’m living in Malaysia now and people here like to make a kind of food. They call it “Enzyme”. Do you know about that?
There are several ways to make a homemade enzyme. The most popular one is like to brew fruit wine without any starter culture. They cut the fruit( any kind of fruit they like) to small pieces and divide those fruits into three or four groups. Take a container and then put one layer fruit, one layer sugar(molasses,gibraltar or brown sugar…) and so forth. Cover it And then let it be fermented several weeks. It will extract the juice and that is whtat they want. They like to drink it for health.
I’m just curios is that safe without any knowledge basis (That is not a traditional food, just only about ten years). Will it creat anything like probiotics? How can I find any more information about the fermented food crisis?
Thanks very much.