What should I choose when I go to the pharmacy? There is a range of products available on the shelves, but their effects and impact on health vary.

• Probiotics are selected cultures of bacteria (usually lactic acid) or yeast that have an immunostimulating effect in the digestive tract. Probiotics help to maintain a normal physiological flora. Probiotic bacteria prevent intestinal infections by producing a range of natural defence substances that inhibit the 'attachment' of other microorganisms to the intestinal epithelium. Probiotics help to restore normal intestinal flora in post-antibiotic diarrhoea or viral infections.
• Prebiotics are substances that are present in the food or are intentionally introduced into the food, and their function is to stimulate the development of normal intestinal flora by encouraging the growth of beneficial intestinal flora. Prebiotics include starch, dietary fibre, lactulose and mannooligosaccharides. A prebiotic does not contain a probiotic or any other micro-organisms, but only stimulants. Prebiotics are fermented in the digestive tract of the host. Products rich in naturally occurring prebiotics are chicory root, dandelion, wheat bran.
• A synbiotic is a combination of a probiotic, i.e. live myco-organisms, with a prebiotic, i.e. a substance designed to promote the growth of myco-organisms. For example, it is a combination of a substance that promotes the growth of lactic acid bacilli together with the addition of these bacteria.

What to choose when looking at pharmacy shelves? It is always advisable to consult your pharmacist before choosing. In the case of antibiotic therapy, probiotics are essential; prebiotics alone may not be effective.