Prebiotics are not digested in the digestive tract, they are a breeding ground for beneficial intestinal bacteria (probiotics), and thus have a positive effect on the human body. We find them in many plant products. They are also used as an additive to functional and dietetic foods and as an ingredient improving the quality of finished products in the food industry.

Properties of prebiotics

Prebioticsare non-digestible food ingredients that have a positive effect on the host's body by stimulating the growth of beneficial intestinal bacteria. The intestines are inhabited by about 1.5-2 kg of bacteria of various species, both those necessary for the proper functioning and pathogenic, causing diseases. The qualitative and quantitative composition of the intestinal microflora is variable and is largely influenced by the diet. Prebiotics increase the amount of beneficial bacteria in the intestines from theLactobacillus, BifidobacteriumandBacterioides .

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For a product (food or supplement) to be considered a prebiotic, it must meet the following conditions:

  • stimulate the growth and activity of selected bacterial strains that have a beneficial effect on he alth,
  • lower the pH of the intestinal contents,
  • be resistant to hydrolysis and the action of gastrointestinal enzymes,
  • not be absorbed in the upper gastrointestinal tract,
  • to feed one or more beneficial microorganisms in the colon,
  • be stable in the food processing process.

Role and action of prebiotics

The role of prebiotics in the body is very important. It is often identified with the role of dietary fiber, but it is not entirely correct. Prebiotics do belong to the fiber fraction, but not all types of fiber are prebiotic. Prebiotics are designed to nourish the colon microbiota, and their effects include:

  • restoring the balance of the intestinal microflora, e.g. after antibiotic therapy,
  • relieve constipation,
  • diarrhea prevention,
  • lowering the pH of the intestinal contents,
  • supporting the absorption of minerals,
  • lowering blood cholesterol,
  • reduction of the risk of colon cancer,
  • positive effect on the immune system.

Prebiotics reach the large intestine unchanged and are fermented by bacteria inhabiting this part of the digestive tract. As prebiotics pass through the lumen of the intestine, they bind water and increase the volume of the intestinal contents. Due to the loose structure and large surface area, these contents provide a good breeding ground for bacteria. Both increasing the volume of fecal masses and the production of gases in the fermentation process promote better intestinal perist altics, prevent constipation, allow you to get rid of toxins from the body faster, and thus reduce the risk of colon cancer. In the process of fermentation of prebiotics, short-chain fatty acids are formed, which play an extremely important role in the proper functioning of the intestines. They are a breeding ground for beneficial bacteria, and at the same time inhibit the growth of pathogens, accelerate the healing and regeneration processes of the intestinal epithelium, increase the production of mucus, maintain the correct pH in the intestine, which limits the growth of pathogenic bacteria, increase the absorption of calcium, iron and magnesium, and also have an effect. beneficial for glucose and protein metabolism in the liver.

Types and sources of prebiotics

Prebiotics are non-digestible carbohydrates in the digestive tract. Among them, there are oligosaccharides and polysaccharides. Among the oligosaccharides, fructooligosaccharides, lactulose and soy oligosaccharides are of the greatest importance for humans. Among the polysaccharides, mention may be made of inulin, resistant starch, cellulose, hemicelluloses and pectins. Some of these compounds occur naturally in food as fiber. Others are obtained through chemical and enzymatic processes and then added to foods or made supplements.

  • Natural sourcefructooligosaccharidesare, inter alia, onions, asparagus, wheat, bananas, potatoes, and honey. Industrially, as a food additive, they are produced by the breakdown of inulin or by synthesis from sucrose.
  • Lactuloseis obtained by converting lactose from milk.
  • A very good source ofsoy oligosaccharidesis soy, especially soy whey - a by-product of soy protein production.
  • Inulinoccurs naturally in chicory, onions, garlic, Jerusalem artichoke, tomatoes, bananas and wheat.
  • Starchis usually a compound easily digested by humans. However, a small part of it (resistant starch) passes through the gastrointestinal tract unchanged. To obtain resistant starch, chemical or physical modifications are made which reduce the possibilitydigestion of starch by amylolytic enzymes.
  • Celluloseis found in the cell walls of all plants, some fungi and bacteria. We can find it in fruits, vegetables and grains, but the most cellulose is flax, cotton and hemp. On an industrial scale, it is mainly obtained from wood.
  • Hemicellulosesare found in food in seeds and bran. Their production sources are wood and straw.
  • Pectinsare found naturally in all fruits and vegetables. On average, they make up 35% of plant cell walls. In industry, their source is dried apple pomace and lemon peel.

Prebiotics such as fructooligosaccharides, soy oligosaccharides, inulin, cellulose and pectins are found naturally in foods and we can provide them with the diet. Often, however, these substances are used in the food industry, both to create functional food with a beneficial effect on he alth, but also as sugar or fat substitutes, gelling, stabilizing, improving the consistency and durability of products.

Worth knowing

Prebiotics in processed foods

Prebiotics can be found in ready-made food in such products as:

  • low-calorie foods (soft, light), e.g. low-fat cottage cheese and dairy desserts, chocolate products, cakes, candies and creams,
  • diabetic food,
  • yoghurts,
  • fruit drinks,
  • jellies and jams,
  • bread,
  • meat products,
  • sweets,
  • soups and sauces,
  • baby food, milk mixtures.

Supplements with prebiotics

Prebiotic supplements are not very common. First of all, due to the fact that by feeding on a rational diet containing plant products, we cover the body's need for these ingredients. An effective dose of prebiotics for an adult is 5-10 g per day, which is what the average diet provides. It is worth reaching for prebiotics from the pharmacy when we have problems with defecation, diarrhea, have undergone antibiotic therapy or our diet is monotonous. We will most often buy prebiotic supplements in the form of liquids, sachets and capsules. Especially popular are those based on aloe and lactulose in the form of a syrup.

In the pharmacy we will also get synbiotics, i.e. preparations that combine probiotics (beneficial intestinal bacteria) and prebiotics (medium for their growth). They are recommended when it is necessary to rebuild the intestinal microbiota, especially after treatment with antibiotics and in digestive problems in the lower sections of the gastrointestinal tract.

Sources:

1.Ślizewska K., Nowak A., Barczyńska R., Libudzisz Z., Prebiotics - definition, properties and application in industry, Food. Science. Technology. Quality., 2013, 1 (86), 5-20

2. Gut he alth - Flair-Flow Europe synthetic report on the effects of pre- and probiotics

3. Kuczyńska B., Wasilewska A., Biczysko M., Banasiewicz T., Drews M., Short-chain fatty acids - mechanisms of action, potential clinical applications and dietary recommendations, Nowiny Lekarskie, 2011, 80, 4, 299-304

4. Wikiera A., Mika M., Structure and properties of pectins, Postępy Biochemii, 2013, 59 (1), 89-94

Category:

Immune system