Probiotics
Another group of active non-nutrients consists of live bacteria, called probiotics (‘pro’ means ‘for’, ‘bio’ means ‘life’). They aim to increase the levels of beneficial bacteria in your digestive system, and reduce the level of harmful or pathogenic bacteria.
Types of probiotics
The main types of probiotics used in food or as supplements are Lactobacillus acidophilus and Bifidobacteria. These bacteria form a major part of your normal intestinal microflora.
Role of probiotics in the diet
There are a variety of bacterial strains in different areas of your gastrointestinal tract, with beneficial functions including:
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prevention and treatment of diarrhoea, lactose intolerance, gastritis and constipation
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resistance to pathogens
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enzyme production in the large intestine
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stimulation of the intestinal immune system
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reduction of risk of colon cancer
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reduction of blood cholesterol concentration.
These functions might be reduced when there is a decline in the balance of the beneficial intestinal microflora. This decline may be due to infections or medications, especially antibiotics.
Sources of probiotics
Probiotics are used in the production of foods prepared by using bacterial cultures, such as yoghurt and specialised fermented preparations such as Yakult. More recently, probiotic dairy products have appeared on the market, for example Dairy Farmer’s Life milk and Mainland Inner Balance cheese. To be effective, the bacterial strains must be:
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of the same type as the beneficial bacteria in your gut
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alive in appreciable numbers by the product’s use-by or best-before date
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able to survive the acids and enzymes of digestion to reproduce in the intestines.
An increasing number of probiotic preparations on the market are designed to be taken daily in small daily amounts to maintain a high level of beneficial bacteria in the intestinal microflora. They are promoted as beneficial even when you have no gastric problems.
Two main questions to be answered are:
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do you need probiotics if you have no intestinal problems?
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do probiotics work as they are claimed?
Something good may indeed happen, but this has yet to be scientifically demonstrated.