What are prebiotics?
The large intestine is one of the most densely populated areas of the digestive system. There are about 1 trillion bacteria and other microorganisms in one gram of intestinal content. The entirety of these organisms is known as the gut microbiome or intestinal flora. Some of these strains of bacteria are not only important for a good digestion but also offer many other health benefits.
Prebiotics are certain nutrients that have a positive effect on the gut microbiome. They are intended to supply and strengthen specific bacterial strains, such as Bifido or Lactobacillus, which are known as good intestinal bacteria with nutrients. This can prevent the excessive spread of harmful bacterial cultures, which can also colonize the intestine.
The effect of prebiotics was known to scientists long before they could name or define them. So they spoke in the 1950s of the 'bifidus factor' that is contained in breast milk. They were able to prove that feeding breast milk in infants led to the accumulation of bifidobacteria in the intestine.
Between the 1980s and the early 1990s, scientists were able to identify various oligosaccharides that also had a positive effect on the intestinal flora. However, since there was no clear definition at this point and the term prebiotics was a long way off, these nutrients were simply referred to as growth factors for the bacterial strains.
The prebiotic concept was first defined in 1995 by the two scientists Glenn Gibson and Marcel Roberfroid. Their formulation has been supplemented by research work over the past two decades. However, the basic principle of their definition is still valid.
Prebiotics definition and delimitation
As research into prebiotics has not yet been completed, the definition also changes over time and is continually supplemented and adapted. Roberfroid and Gibson presented the first definition of prebiotics with their prebiotic concept:
'A prebiotic is an indigestible food component that has a positive effect on the host (human) and thus on the health by stimulating the growth or the activity of one or a certain group of bacteria in the intestine.'
A decisive addition was later added to this definition. Prebiotics are only indigestible for the host; the intestinal bacteria are partially able to utilize them. They serve as its nourishment and thus promote the growth and activity of these bacterial strains.
Most of the prebiotics known today are short chain carbohydrates. However, current research suggests that other nutrients, such as riboflavin, may also have a prebiotic effect.
There are also occasional misunderstandings regarding the terms prebiotics and bifidogenic factor. The bifidogenic factor favors bifidobacteria, which are good intestinal bacteria and is therefore prebiotic. But there are also many other good intestinal bacteria, such as lactic acid bacteria, which are not necessarily influenced by bifidogenic factors. A prebiotic is therefore more than the bifidogenic factor.
A prebiotic must meet the following criteria to meet the above stated definition:
- A prebiotic is not a living organism.
- It must be resistant to gastric acid and other digestive secretions from the human body in order to get into the colon undigested.
- Prebiotics must be able to be utilized by the intestinal flora.
- They must have a positive effect on the activity or growth of at least one healthy intestinal bacterium.
Prebiotics and probiotics (Synbiotics)
The terms prebiotics and probiotics not only sound very similar, but are also closely related in their function. Nevertheless, there are misunderstandings and misinterpretations of the two terms even among experts. A study from 2014 presented a questionnaire on prebiotics and probiotics to 256 healthcare professionals.
It was found that 88% of the people questioned were familiar with probiotics and their health-promoting effects. However, only 22% were familiar with prebiotics and their function. Everyday life also shows that probiotics are generally better accepted and better known. One factor in this could be that there was significantly longer and more intensive research on probiotics.
The term probiotics is derived from the Greek language. The term was originally used as a contrast to antibiotics. The term was first used in 1965, but its current meaning did not make it until 1974.
What distinguishes probiotics from prebiotics?
Probiotics are living, non-pathogenic microorganisms, such as bacteria and yeast, that are beneficial for the host and the digestive system. The prebiotics, on the other hand, are nutrients that the probiotics can utilize.
The human intestine is populated by numerous microorganisms, all of which have not yet been identified and assigned. Probiotics can consist of a specific bacterial strain or a mixed culture. It is essential that they reach the colon alive and are beneficial for humans and their digestive system.
Should prebiotics and probiotics be used together?
Food or food supplements that contain both probiotics and prebiotics are called synbiotics, sometimes also symbiotics. Researchers have looked at the benefits of such combination products. The use of these synbiotics can have a health-promoting effect.
Synbiotics ensure that good strains of bacteria colonize the intestine and strengthen them at the same time by providing the necessary nutrients for the prebiotics. The researchers are convinced that synbiotics can be more beneficial in some cases. For people whose intestinal flora has become unbalanced due to an illness or due to the use of strong antibiotics, the use of a synbiotic can be useful.
Postbiotics or paraprobiotics are relatively new terms. If prebiotics are used by probiotics, postbiotics are created. Although they are essentially a waste product of the metabolism of probiotic organisms, some researchers believe that they can have a positive effect on the human body.
Postbiotics can be, for example, enzymes, peptides, cell wall components or other substances. The scientists believe that they could have anti-inflammatory, immunomodulatory, hypotensive, hypocholesterolemic and antioxidant effects, among other things. However, since the research field is very new, the exact effect mechanism have not yet been clarified.
In early research, there were two recognized groups of prebiotics that met all the criteria of the definition:
- Fructo-oligosaccharides (FOS)
- Galacto-oligosaccharides (GOS)
Today we know that other dietary fibers, such as resistant starch or other plant polysaccharides as well as lactulose, can have a prebiotic effect.
Fructo-oligosaccharides consist of short-chain D-fructose. Since they are indigestible for the human body, they are also preferred as a low-calorie sweetener.
Depending on the chain length and the degree of polymerization (DP), a distinction is made between oligofructose (on average 4.8 DP) and inulin (up to 60 DP). Inulin was first discovered in 1879, but at this point its prebiotic effects were not yet known.
Studies have shown that oligofructose and inulin significantly increased the number of bifidobacteria in the large intestine. However, the total mass of the bacteria in the stool did not change. This suggests that the FOS not only fulfills a prebiotic but also a bifidogenic effect.
Galacto-oligosaccharide (GOS) is a group of carbohydrates that are indigestible for humans. Other synonyms are trans-oligosaccharide or trans-galacto-oligosaccharide. A sugar similar to this oligosaccharide is naturally found in breast milk. Researchers believe that this prebiotic protects infants from colonization by pathogenic germs in the intestine.
GOS can be fermented by bifidobacteria and to a certain extent also by Lactobacillus strains. They are often used as an additive in baby food.
Prebiotics are indigestible carbohydrates for humans and therefore so-called fiber. For the intestinal flora, on the other hand, they are important nutrients that can be broken down by fermentation. This creates short-chain fatty acids such as acetate, propionate, butyrate, also known as butyric acid and other metabolites and various gases.
These short-chain fatty acids ensure that the pH in the intestinal lumen drops. This in turn leads to an unfavorable environment for the undesirable and pathogenic germs, which would otherwise increase there. They also supply the intestinal epithelium with energy and regenerate the intestinal mucosa.
The prebiotics not only support a balanced and healthy intestinal flora. They also promote intestinal motility. Butyrates, acetates and other metabolites also have many positive effects on the body.
The exact need for prebiotics is not defined. Because the structure of the gut microbiome is different for every person. There are various reasons for this, such as genes, but lifestyle, nutrition and the environment can also play a role. The European Food Safety Authority (EFSA) generally recommends a daily intake of 25 g of fiber per day, regardless of gender.
For a demonstrable bifidogenic effect, researchers recommend taking in at least 4 g of fructo-oligosaccharides. Another in vivo study in healthy volunteers examined the effects of different dosages of FOS.
40 subjects between the ages of 18 and 47 participated in the study. They were divided into 5 groups and received between 0 g and 20 g FOS per day. With regard to the tolerance and the increase of bifidobacteria in the stool, the group with the dosage of 10 g per day achieved the best result.
Archaeological tests showed how the uptake and tolerance of prebiotics has changed over time. Researchers found dry cave deposits, skeletons and fossilized human excrements in the northern Chihuahua desert in Mexico. They examined them for their inulin-like fructan content.
The found fossils date back to 10,000 years and suggest that the average amount of inulin-like fructans consumed in adults was around 135 g per day. The researchers assume that due to drought, agriculture did not work properly at the time. Therefore, in addition to hunting, nutrition was also ensured with many wild plants - in particular through succulents and root vegetables such as agave, prickly pear, onions and manioc.
Carbohydrates that are indigestible to humans are important for the growth of intestinal bacteria. Prebiotics such as inulin and other oligosaccharides are particularly advantageous because they favor the good intestinal bacteria. If the good bacteria are not adequately cared for, pathogenic bacteria can spread in the intestine and disturb the balance of the intestinal flora.
While these carbohydrates are the preferred energy source for intestinal bacteria, some strains of bacteria such as streptococci, clostridia and bacillus can also utilize proteins. The breakdown products of this metabolism are not as beneficial to health as the short-chain fatty acids that are produced during the fermentation of prebiotics, but can be partially toxic to humans.
The results of a prebiotic deficiency can have a far-reaching effect on human health:
- Constipation or irregular bowel movements
- Disruption of metabolism and the absorption of minerals and other important micronutrients
- Possible factor for obesity
- Inflammatory diseases of the intestine
- Disorder of the immune system and defense against pathogens
- Increased risk of colon cancer
Most prebiotics belong to the dietary fibers and are found in their natural form, especially in plant foods with a high fiber content. This includes fruits, vegetables as well as legumes and cereals. Breast milk also contains prebiotic ingredients, such as lactulose. In addition to these natural sources, there are also various industrially manufactured and processed foods that contain prebiotic additives.
Prebiotics in food
While prebiotics are a type of fiber, not all fiber has a prebiotic effect. The prebiotics content is particularly high in the following foods:
- Chicory root: Because of its taste, the chicory root is often used as a substitute for coffee. At 100 g, the chicory root contains an average of approximately 41.6 g inulin and 22.9 g oligofructose.
- Dandelion leaves: The green leaves of the dandelion are ideal for fresh salads. When raw, the leaves contain about 13.5 g inulin and 10.8 g oligofructose per 100 g. If the leaves are cooked, the content drops to 9.1 g and 7.3 g, respectively.
- Jerusalem artichoke: Jerusalem artichoke is a root vegetable that is related to sunflower and cassava. In some regions it is also known as the potato, sunroot, horse apple or Jerusalem Artichoke. Topinambur contains an average of 18 g inulin and 13.5 g oligofructose per 100 g total weight.
- Garlic: Garlic is widely known for its health-promoting ingredients. The garlic fructan contained in it also showed a prebiotic effect in some studies. It selectively supports the growth of bifidobacteria. In addition, garlic contains 12.5 g inulin and 5 g oligofructose per 100 g fresh material.
- Onions and leeks: Onions and leeks not only have an antibacterial effect like garlic and can reduce the risk of gastrointestinal cancer, they also contain many prebiotically active nutrients. Raw onions contain 4.3 g of inulin and oligofructose per 100 g. If they are dried raw, they even contain an average of 18.3 g.
- Asparagus: Asparagus is a popular seasonal vegetable. With 2.5 g inulin and 1.7 g oligofructose per 100 g in the cooked state, the content is low compared to the previously mentioned. For a varied diet, it can still make sense to include asparagus in the menu if the season permits.
Bananas: The popular fruit is known for its high content of vitamins and minerals and is also high in fiber. Nevertheless, the content of inulin and oligofructose is very low at 0.5 g per 100 g. However, green bananas contain resistant starch, which is also thought to have a prebiotic effect.
In one study, subjects ate flour obtained from freeze-dried green bananas. Of the total a-glucans ingested, 83.7% reached the last section of the small intestine and were almost completely fermented in the large intestine.
Barley: Barley is a popular grain and is used to make beer. The prebiotically active factor are the beta-glucans, which particularly favor the growth of lactic acid bacteria. Barley contains about 3–8 g beta-glucan in dry weight.
The inulin and oligofructose content, on the other hand, is comparatively low and is around 0.8 g raw and 0.2 g cooked per 100 g barley.
- Oats: Due to the high fiber content, oats are a real satiety. In the unprocessed state, oat kernel contains about 85% insoluble fiber. Just like barley, oats contain valuable beta-glucans, which are said to have a health-promoting effect.
Prebiotics as a food additive
Like probiotics, prebiotics are among the most frequently used food additives. While the declaration of probiotics is widespread, the specification of prebiotics as a food additive is less common. Most of them are only counted as a general fiber.
However, the inclusion of prebiotics as a food additive can make sense. Because their content in natural foods is comparatively low, so that many people can't always reach the recommended daily amounts. A supplementary intake can therefore be beneficial for your health.
Industrially manufactured prebiotics
Prebiotics are industrially produced as food additives. The procedure depends on the type of prebiotic. For example, inulin is often obtained from Jerusalem artichoke and chicory root, since these have a comparatively high inulin content.
In contrast, galacto-oligosaccharides (GOS) are obtained from milk sugar by enzymatic hydrolysis. For this purpose, enzymes such as glycosidases are used, which are obtained from different bacterial strains.
Prebiotics and nutrition
Researchers agree that the composition of the intestinal flora depends on many factors. Nutrition and environmental influences are crucial. Because these can be influenced and contribute to health or illness.
A study from 2010 compared stool samples from children from a rural area in Africa and from Europe to obtain conclusions about the composition of the intestinal flora. The diet of African children was high in fiber as compared to the European group.
It was shown that there were not only significant differences in the quantitative ratio of individual bacterial strains. African children also found species that European children seemed to lack entirely. This type of bacteria has special genes that make it possible to break down cellulose that can't actually be used by humans.
The intestinal flora of African children was able to better utilize fiber and also achieve a higher concentration of short-chain fatty acids. The researchers suspect that these effects can be attributed to the diet, which is characterized above all by the high fiber and polysaccharide content.
Some foods can do more than just fill you up and provide energy or nutrients. Certain foods, like prebiotics, promote health and can reduce the risk of certain diseases. Such foods are called functional foods.
Prebiotics and the healthy intestinal flora
The intestine is a complex ecosystem consisting of a wide variety of bacteria and microorganisms. Researchers estimate that around 50 different genera and 500 bacterial species live in the human gut. Most of them have a positive effect on health and contribute to the body's natural processes.
If the intestinal flora becomes unbalanced, we refer to it as a dysbiosis. The reasons for this can be different:
- Mental or physical stress
- A protein-rich diet, in particular a high proportion of animal proteins is harmful.
- Too many simple sugars and refined carbohydrates can also trigger dysbiosis.
Some effects of dysbiosis, such as an upset stomach or diarrhea, are temporary and mild. In many cases, the body can correct the imbalance with a change in diet and a healthy lifestyle. However, if the first symptoms are ignored, the consequences can become more serious.
Prebiotics and bloating
Flatulence is generally attributed to a poor diet or certain foods. Flatulence is normal, even if socially frowned upon. When food passes through the digestive tract, it is used by the body and bacteria.
Gases are produced as a breakdown product or a by-product in these processes. Flatulence can also result from swallowed air. However, most of these gases, such as hydrogen, oxygen or carbon dioxide, are barely noticeable when they are present in small quantities.
Most gases in the body are produced by bacteria during the fermentation of nutrients that are removed from the body through flatulence. The unpleasant smell is triggered by sulfur gases. Sulfur is found in many foods, medications and even in drinking water.
However, only certain strains of bacteria in the gut microbiome are able to process and release the sulfur-containing nutrients. These bacteria can't grow in an acidic environment. The good bacteria in the intestine can therefore form short-chain fatty acids through the use of prebiotics, which contribute to the acidification of the large intestine and reduce the formation of sulfur gases.
Prebiotics and digestion
A large part of the digestion takes place in the intestine. According to the current state of science, the gut microbiome influences digestion at various levels. Depending on how diverse the composition is and which strains of bacteria predominate, the transit time in the colon and the stool consistency changes.
Another study from 2018 examined how chronic functional constipation can be treated with the help of probiotics, prebiotics and synbiotics. The first results suggest that improving the intestinal flora and enriching beneficial strains of bacteria can alleviate the symptoms. Since this treatment method, unlike traditional treatments, does not involve any possible complications, the researchers recommend continuing clinical research and its use.
Prebiotics and chronic inflammatory bowel diseases
The most common and most widespread chronic inflammatory bowel diseases (IBD) include Crohn's disease and ulcerative colitis. Crohn's disease is a chronic, recurring inflammatory disease of the intestinal tract.
Researchers believe that one reason for IBD is an overly strong immune system response to harmless, non-pathogenic bacteria in the gut. Both clinical and experimental studies have shown that this changes the balance between healthy and harmful bacteria in the intestine.
Based on this, the scientists suspect that adjusting the intestinal flora using probiotic and prebiotic preparations can be a possible treatment for IBD. Currently however, these hypotheses are not fully supported, as there are only a few and small clinical and experimental studies on this topic. Research will have to provide further evidence in the future.
Prebiotics and colon cancer
Colon cancer is one of the most common types of cancer. Various studies in recent years have suggested that taking prebiotics, probiotics or even combination products could have an anti-carcinogenic effect. Researchers suspect that this effect is due to the activity of healthy intestinal bacteria.
It is believed that this supports communication between the body's immune system and the gut microbiome. This reduces the risk of inflammation in the intestine associated with the formation of polyps and resulting colon cancer.
Prebiotics and the hormonal balance
The sayings 'decide something from the gut' or 'have a bad gut feeling' are widespread. In recent years, scientists have partly been able to prove the truth of these phrases. So they show the existence of an intestinal-brain axis.
This gut-brain axis allows communication between the enteral nervous system (ENS) and the central nervous system in both directions. Recent studies have shown that the CNS and ENS can not only communicate with each other, but that also the bacteria in the intestine can influence the brain and transmit information.
The results, which are mostly obtained from animal test models, indicate that a colonization of the intestine influences the development of the brain during childhood and behavioral patterns in adults. Researchers have also found that the gut microbiome is different in autistic children. The scientists see this as a further indication of their presumption.
Prebiotics and stress
Many may know the feeling when the stress hits the stomach colloquially. This can be shown through indigestion or abdominal pain. In fact, it is already known that acute stress can affect the intestinal flora.
Researchers have looked into whether modulating the intestinal flora with prebiotics can help deal with stress better and recover better from the situation.
The study published in 2017 was carried out on rats. For the study, these animals received prebiotics for several weeks and were then exposed to a stressful situation. The results were then compared to a group of control animals that received no prebiotic diet.
The researchers found that the rats that were fed prebiotic foods, did not show stress-induced disorders in the gut microbiome. They were also able to maintain a healthy sleep pattern that is so important for stress relief.
However, the study is still relatively new and has so far only been carried out on rats. However, the researchers are confident that the results can also be transferred to humans. Further studies have to show how much a prebiotic diet can actually affect the handling of stress and the reduction of sleep disorders in humans.
Prebiotics and the immune system
Every day, a wide variety of foreign substances pass through the body via the intestine. The immune system is designed to protect the body from harmful intruders and prevent them from spreading. It has been scientifically proven that 70 to 80% of the immune system is in the gastrointestinal tract.
Researchers believe that the gut microbiome plays a crucial role in the immune system and helps modulate it. The use of prebiotics can promote healthy intestinal flora and reduce the risk of diseases and inflammatory processes.
Prebiotics and seasonal allergies
What causes allergies? Essentially, an allergy is the result of the immune system's overreaction. The immune system is designed to protect against viruses and bacteria that can make you sick. However, sometimes it is tempting to go on the offensive for no reason.
Seasonal allergies are caused by the body's immune system reacting too aggressively to pollen, ragweed, grass and other harmless substances in the environment. When the immune system sees these substances as a threat, it releases chemicals. These cause the inflammation associated with the annoying allergy symptoms.
Most people believe that allergies last a lifetime. However, this is not necessarily true. It is entirely possible to suddenly fight allergies as an adult, even if you have been spared allergies in the past few decades. In addition to this, many children suffering from seasonal allergies will eventually grow out of their condition. In various studies, researchers have found that there is a connection between the composition of the gut microbiome and allergies.
Low microbiota diversity can lead to an increased susceptibility to allergies, according to a study of 1,879 adults published by the National Institutes of Health. This study found that a lack of diversity in the gut microbiota was associated with all types of allergies. The strongest relationship was observed in people who suffered from seasonal and/or nut allergies. In their gut microbiota, the bacterium clostridiales was reduced and bacteroidales bacterial colonies were increasingly present.
A study by the University of Michigan on laboratory mice appears to support this observation. After drinking water with antibiotics for a few days, the mice showed increased amounts of candida yeast. This is the same result that has been observed in people after taking antibiotics.
After being exposed to allergens such as pollen, dander, dust mites and cockroach droppings, the mice given the antibiotics showed allergy-like symptoms. However, they did not show these symptoms before. The genes of the mice used in the study made no difference, further reinforcing the researchers' suspicion that allergies can be triggered by a distribution in the gut microbiota.
Prebiotics and loosing weight
So far, researchers have agreed that intestinal bacteria plays an important role in metabolism. Initial research on rodents showed that the microbial composition of the intestine was very different in slim and obese animals. Bacteria strains of the firmicutes dominated in heavily overweight animals and the bacteroids in the skinny animals.
Since the bacterial strains in the intestinal tract of mice and humans are very similar, the researchers suspect that the results can also be transferred to the human intestinal microbiome. In 2017, a study was conducted with people to check this assumption.
Canadian researchers from the University of Calgary conducted a placebo-controlled, double-blind study with 42 participants. The participants were children aged 7 to 12 years who were classified as either overweight or obese according to their BMI, but were otherwise healthy. They were divided into two random groups.
One group received prebiotic fibers in the form of inulin enriched with oligofructose, the other group received a placebo from maltodextrin. Both were mixed as a powder in water and taken once a day for 16 weeks. Height, weight, hip circumference as well as feces and blood samples of the test subjects were used for the evaluation.
The researchers found that the weight, body and hip fat percentage of the group taking the prebiotic could be reduced by 2.4 to 3.8% as compared to the initial values. Interleukin-6 levels, which may indicate inflammatory processes in the body and serum triglyceride levels have also been reduced. After the 16 weeks, the composition of the bacterial cultures in the feces also changed.
The Canadian researchers' study was the first randomized controlled trial of this kind. To confirm these initial results, further studies with a wider socio-economic range would have to be carried out. The topic is particularly important because childhood obesity can often persist into adulthood and is associated with many secondary diseases and accompanying complaints.
Prebiotics and cardiovascular diseases
Various research results indicate that there is a connection between the gut microbiome and metabolic disorders or diseases such as obesity and diabetes. These diseases in turn can increase the risk of cardiovascular diseases. In an article from 2014, scientists wrote current research results as questions of whether there is a connection between the activity of intestinal bacteria and the risk of cardiovascular diseases and how a change in diet could affect this.
They concluded that a changing diet, such as taking prebiotics, could reduce the risk. So there seems to be a link between the activity of the gut microbiome and heart health.
In an article from 2016 on the influence of prebiotics and probiotics on cardiovascular diseases and associated metabolic disorders, the authors wrote: 'Probiotics and prebiotics can improve T2DM [type 2 diabetes] and CVD by improving the intestinal microbiota because they do so Insulin signal stimulation and cholesterol-lowering effects. '
In a study from 2018, the authors found that targeted treatment of the intestinal microbiota with inulin-type frutinans can improve the function of the endothelium in blood vessels and reduce the risk of cardiovascular diseases caused by metabolic disorders.
Prebiotics and bone health
The bones are the framework of the human body. They ensure stability and mobility. In the course of life, the bones are exposed to great stress. They also serve the body as a mineral store.
The human skeleton is a living organ that is in a constant process of assembly, disassembly and remodeling. The build-up phase predominates at a young age. After the age of 34, the bone build-up slows down and can no longer keep up with the natural breakdown processes. The bone mass is steadily decreasing and can lead to diseases such as osteoporosis.
It has been known for some years that the increased intake of certain vitamins and minerals can help to reduce the risk of bone loss and osteoporosis. In particular, the vitamins D and K, as well as calcium and magnesium, which are necessary for the building processes of bone material in the body, have stood out here.
When taking nutritional supplements, however, it is particularly important that the vitamins and nutrients can be properly absorbed by the body. Studies have shown that prebiotics can help increase the absorption of certain minerals.
Prebiotics and calcium
Of the various minerals that affect bone density and health, calcium receives the most attention. Because calcium is an integral part of bones and the body can't produce them, an adequate food intake is essential for building strong bones and teeth. Without an adequate calcium intake, the body lacks the building blocks to create and preserve bones.
Purdue University researchers recruited 31 healthy girls between the ages of 10 and 13 and divided them into groups. The placebo group drank a smoothie without GOS twice a day, the other two groups received 2.5 g or 5 g smoothies. The study was conducted over a 3 week period.
The results showed that prebiotic smoothies increased the calcium absorption. However, it was also shown that the increase was not related to the level of the GOS dose, since significant improvements were observed in both low and high dose groups. Changes in intestinal flora were also observed, with the population of bifidobacteria increasing significantly in the 5 gram group compared to the control or 10 gram groups.
Prebiotics and magnesium
In addition to calcium, magnesium is also essential for healthy bones. But magnesium also fulfills various other important functions in the body. It is the fourth most common mineral in the body and is also a co-factor in over 300 different enzymatic processes.
Although this mineral is very important for various body functions, Europeans and Americans consume an average of 30 to 50% less magnesium than recommended. Various studies have shown that prebiotics can improve the absorption of magnesium.
Many of these studies have been done on rodents. However, one test from 2009 suggests that taking prebiotics over a longer period of time could also increase magnesium absorption in humans.
Prebiotics and iron
According to the WHO, iron deficiency is still the most common and widespread nutritional disorder in the world. Current iron supplements have limitations in terms of bioavailability and tolerance. Prebiotic fibers, such as galacto-oligosaccharides (GOS), selectively increase the growth of beneficial colon bacteria.
Prebiotics generally improve the production of short chain fatty acids (SCFAs) and thereby reduce the luminal pH. By lowering the colon pH, prebiotics can improve the absorption of minerals such as calcium and magnesium, and it has been suggested that they may also improve iron absorption.
Another study from 2017 looked at the question of whether iron absorption by prebiotics can also be increased in infants. For this purpose, the children aged 6 to 14 months received a special corn porridge once a day for a period of 28 days.
In one group, the corn porridge only contained iron fumerate and sodium iron. The porridge of the other group additionally contained 7.5 g of galacto-oligosaccharides (GOS). The researchers were able to show that iron absorption by GOS could be increased by 62%.
Prebiotics in powder form are tasteless and versatile. Due to the dosage form, additives and shell material, as would be necessary with tablets, can be dispensed with. Another advantage is that it can be consumed directly with food. For example, it can be stirred into drinks or sprinkled directly over food.
Prebiotics powder is often obtained from the chicory root, also known as the common wayward or cichorium intybus. It is considered the archetype of many well-known salad plants such as chicory or radicchio.
Prebiotics can be taken alone or as a synbiotic along with probiotics. There are different ways to integrate prebiotic powder into everyday life:
- stirred into fruit juices and smoothies
- for breakfast with oatmeal or muesli
- stirred into yogurt
- sprinkled on salads
There are currently no precise dosing recommendations for prebiotics. Since everyone reacts differently, users should slowly approach the optimal dose for them. The dosage recommended by the manufacturer is a good guide.
Prebiotics side effects
As a rule, prebiotics are well tolerated. However, special care should be taken for people suffering from a fructose intolerance, fructose malabsorption or lactose intolerance. Depending on the level of intolerance, you should limit consumption or use an appropriate alternative.
People suffering from hereditary fructose intolerance, e.g. an inherited disorder of the fructose metabolism, should avoid prebiotics containing inulin or other fructo-oligosaccharides.
If the dosage is too high, prebiotics can cause diarrhea and/or abdominal pain. Flatulence is another side effect that has been observed.