What are prebiotics?
Prebiotics are food components that cannot be broken down by human digestive enzymes. They pass through the stomach and small intestine largely undigested and reach the large intestine. There, they are metabolised by certain beneficial gut bacteria.
This distinguishes them from many other nutrients: prebiotics do not primarily serve as a direct source of energy for humans, but rather for their gut flora. They provide beneficial gut bacteria such as bifidobacteria and lactobacilli with suitable substrates for their metabolism. This process produces, among other things, short-chain fatty acids such as acetate, propionate and butyrate.
These bacterial metabolites have been a focus of microbiome research for years. They are being investigated, among other things, in connection with the intestinal environment, the nutrition of the intestinal mucosa and the communication between the gut flora and the body.
What is the difference between prebiotics, probiotics and postbiotics?
In connection with gut health, various terms are used that can easily be confused. The terms probiotics and postbiotics should therefore be distinguished from prebiotics:
- Probiotics are live microorganisms that can favourably influence the composition of the gut flora. These include, above all, selected lactic acid bacteria and bifidobacteria. Probiotics are found, for example, in fermented foods or can be taken in the form of food supplements.
- Postbiotics are metabolic products or components of beneficial microorganisms. These include, for example, short-chain fatty acids that are produced during the bacterial fermentation of dietary fibre.
A combination of probiotic bacterial cultures and prebiotic dietary fibres is referred to as a synbiotic. Such a product not only provides beneficial microorganisms, but also supports their growth at the same time through the prebiotics it contains.
The Allvital product ProBio14 is such a synbiotic, combining 14 selected bacterial cultures with the prebiotics inulin and fructooligosaccharides.
Are prebiotics the same as dietary fibre?
Dietary fibres are indigestible components of plant-based foods. Many prebiotics belong to the group of dietary fibres, but the terms are not synonymous. The decisive point is this: a dietary fibre is only considered prebiotic if it can be selectively utilised by certain gut bacteria and thereby has a favourable effect on the microbial balance.
Insoluble dietary fibres such as cellulose or lignin are only minimally or not at all fermented by gut bacteria. They are therefore not considered classic prebiotics. Nevertheless, they are important for gut health, as they increase stool volume, support intestinal transit and thus also detoxification via the gut, while at the same time improving stool consistency.
Which prebiotics are there and in which foods are they found?
Many well-studied prebiotics belong to the group of soluble dietary fibres. They can bind water and partly form a gel-like consistency in the gut. However, the decisive factor for their prebiotic effect is above all that they can be utilised by beneficial gut bacteria. Important examples include:
- Inulin and fructooligosaccharides: They occur naturally, for example, in chicory, Jerusalem artichokes, onions, garlic, leeks, asparagus and artichokes, and are among the best-known prebiotics.
- Resistant starch: This is formed, among other things, when cooked potatoes, rice or pasta cool down. In the process, part of the starch changes its structure so that it is less easily digested in the small intestine and reaches deeper sections of the intestine. Green bananas, legumes and wholegrain products can also provide resistant starch.
- Resistant dextrins: These are special indigestible carbohydrates that are usually obtained from starch. They are often used in food supplements or fibre-enriched foods and can be fermented by gut bacteria.
- Beta-glucans: These soluble dietary fibres are found mainly in oats and barley. Certain mushrooms also contain beta-glucans, although their structure differs from that of cereal beta-glucans.
- Pectin: Pectin is found mainly in apples, berries, citrus fruits, carrots and other types of fruit and vegetables.
- Acacia fibres: Acacia fibres are obtained from the sap of certain acacia species. They are highly soluble, mild in taste and are frequently used as a prebiotic dietary fibre in food supplements.
Chia seeds, flaxseeds and psyllium husks also provide valuable soluble dietary fibres and mucilage. They bind a large amount of water and form a gel-like consistency in the gut. This can support intestinal activity. Unlike classic prebiotics such as inulin, fructooligosaccharides or pectin, however, they do not primarily act through targeted fermentation by certain gut bacteria, but mainly through their swelling and gel-forming properties.
In addition to the soluble dietary fibres mentioned, prebiotic effects can also be achieved through certain secondary plant compounds, especially polyphenols. These can interact with the microbiome and support the growth of beneficial gut bacteria. Polyphenols are found, among other things, in berries, grapes, pomegranate, cocoa, green tea, coffee, herbs, spices, olives and brightly coloured vegetables.
For a healthy microbiome, it is not a single prebiotic that is decisive, but the daily intake of a variety of different prebiotic substances. A plant-based diet with many different types of vegetables, fruit, legumes, wholegrain products, nuts and seeds is therefore particularly favourable.
How much dietary fibre should you eat every day?
For adults, a daily dietary fibre intake of at least 30 g is recommended. This amount refers to dietary fibre as a whole, not exclusively to prebiotics. In everyday life, however, most people fall far short of this guideline.
In addition to increasing the dietary fibre content of the diet, fibre powders such as Jerusalem artichoke powder, acacia fibres, baobab powder or mixtures of various prebiotics can also be used as a supplement and, for example, stirred into a smoothie.
Possible effects of prebiotics on gut health
Eating foods rich in prebiotics or taking corresponding food supplements can have various benefits for health.
Promoting healthy gut flora
Prebiotics serve specifically as food for beneficial gut bacteria such as bifidobacteria and lactobacilli. As a result, they promote their proliferation and metabolism and create favourable conditions for healthy gut flora.
Formation of short-chain fatty acids and lactic acid
When prebiotics are metabolised by the gut flora, short-chain fatty acids such as butyrate, acetate and propionate, as well as other beneficial bacterial metabolites, are produced. As mentioned at the beginning, these substances are also referred to as postbiotics.
Postbiotics, especially short-chain fatty acids, serve as an energy source for the cells of the intestinal mucosa. This could help strengthen the intestinal barrier and protect against increased permeability of the intestinal barrier (leaky gut syndrome).
Furthermore, short-chain fatty acids and the lactic acid produced support a healthy pH value in the gut. This lies in the slightly acidic range at around 5.8 to 6.5. Such a pH value inhibits the proliferation of many potentially harmful germs.
However, the health-promoting effects of short-chain fatty acids are not limited to the gut, but can affect the entire organism. The investigation of their mode of action and clinical application is the subject of many current research projects. The main areas of focus include in particular:
- Anti-inflammatory effects and immune regulation
- Strengthening mental health via the gut-brain axis
- Promoting metabolic health
Prebiotics as food supplements
The most important source of prebiotics is a fibre-rich diet. Nevertheless, food supplements can make a valuable contribution to compensating for deficits in stressful everyday life or when travelling.
When using fibre powders, it is advisable to increase the dose slowly and divide the portion throughout the day so that the gut can gradually get used to the higher dose. A sudden large amount of dietary fibre can lead to bloating, a feeling of fullness or even constipation. Constipation occurs particularly when not enough fluid is consumed, as swelling fibres can bind a large amount of water in the gut.
Allvital products to support gut health
Our central product for strengthening gut health is ProBio14. Each daily dose contains 15 billion CFU of probiotics as well as 400 mg inulin and 300 mg fructooligosaccharides. ProBio 14 contains 14 different types of bifidobacteria, lactobacilli and Streptococcus thermophilus, a bacterium that occurs naturally in fermented foods. All included species have been investigated in scientific studies with regard to safety and efficacy.
It should be noted that ProBio14 is not suitable for people with histamine intolerance, as some of the included species can form biogenic amines, which could potentially worsen symptoms in sensitive individuals.
Another important product for gut health is Gut-Brain-Complex. The preparation was specifically developed to support the gut-brain axis and contains propionic acid, L-glutamine, choline and extracts from cat’s claw and lapacho.
To support digestion, taking Enzyme Complex is also recommended. It combines various plant enzymes, thereby promoting the digestion of carbohydrates, fats and proteins. The product is particularly suitable for people with impaired digestive capacity or a weakened intestinal barrier, in order to reduce digestive residues that can burden the gut.
BioHumin is also suitable for binding harmful substances in the gut. The preparation should be taken with as much time as possible between food and other supplements.
