Fermentation of plants is becoming more popular. What’s the purpose of this fermentation?

Discover the magical benefits!

Fermentation of foodstuffs has existed for thousands of years and evokes in many people the image of rising bread or the preparation of beer and wine.

Especially in Asia, there are still numerous population groups that put fermented foods such as Japanese miso, tempeh and Korean kimchi on the menu on a daily basis. Soy sauce is also a famous fermented product. Aspergillus oryzae is a fungus used to obtain miso.

In Europe we mainly know fermented white cabbage or sauerkraut and yoghurt. These products are fermented by specific lactic acid bacteria. Unfortunately, fermented food has largely disappeared from the western diet.

More and more people come to the conclusion that the fermentation of plants can be very useful. A transformation is clearly taking place. The taste and colour change as well as the shelf life of the fermented products increases. The transformation process with the original products therefore provides interesting advantages.

For example, in the case of wine, fermentation changes the aspect of the product. Using yeast, the very sweet grape is transformed into a dry, tasty and aromatic liquid. A liquid that also preserves very well. When making beer, the sugars of the grains are also transformed. Fermentation will partly mean the conversion of sugars into alcohol by fermentation, but will also add other, new aromatic substances to the liquid. Different micro-organisms give different new aromatics.  An example is the bacterial secondary fermentation in the production of the Belgian Gueuzebeer. But the bacterial fermentation of the unique abbey beer Orval is also an example of how not only yeasts but also bacteria play a role in enriching a product.

Fermentation is a pre-digestion of complex foods.

Some foods are not suitable for us. Take, for example, grass. Grass contains a high percentage of cellulose fibres that we cannot digest. Cows and other ruminants can. They have several stomachs with different types of micro-organisms that can convert the starch of the grass into useful sugars. So, there is a kind of pre-digestion. Specialised bacteria produce enzymes that can break down the cellulose and convert it into useful sugars.

Our food also contains many components that can only be digested by the intestinal flora with its more than 300 different microorganisms.  However, our intestinal flora has changed a lot compared to, for example, a few thousand years ago, or even decades ago.

The diet of our modern society has led to the fact that we have too many microorganisms in our microbiome that are either specialized in the digestion of starch or in the digestion of proteins. The intestinal flora is disturbed, and we often don’t have enough microorganisms to ensure a complete digestion of our food. This variety of healthy bacteria ensure good health by making a.o. micronutrients such as vitamins, minerals and antioxidants bioavailable.

The role of fermentation in making nutrients available.

The bioavailability or accessibility of nutrients is essential for their usefulness. Below are a number of examples of the role of fermentation:

  • Fermentation of grains increases the vitamin B content.
  • Certain lactic acid bacteria even have the ability to synthesise water-soluble vitamins such as B vitamins.
  • Fermentation improves the amino acid and vitamin composition of food.
  • Minerals such as zinc become more bioavailable through chelation.
  • Fermentation increases the bioavailability of the secondary metabolites or active substances from medicinal plants.

The role of fermentation in the activation of active substances

Polyphenols have an antioxidant power and occur naturally in fruits, vegetables, nuts, seeds, leaves, rhizomes, flowers, plant bark. In short, almost everywhere.  However, these polyphenols are often poorly soluble. Therefore, they are not as powerful as they could be. Because of the fermentation, the polyphenols are cut into smaller pieces. This makes them more soluble and much more active. This process often happens in the large intestine because the large intestine needs a lot of antioxidants to protect the mucosa. However, if the intestinal flora is disturbed, this activation is lacking, and the intestine will start to inflame.  This inflammation disturbs the immune system around the intestine and gradually evolves into a catastrophic situation. Fermented vegetables or, for example, berries will be of great help to these people because of their high polyphenol content.

Spontaneous fermentation of garlic resulted in an increased antioxidant activity of the garlic with a 13-fold increase in superoxide dismutase (SOD)-like activity and a more like tenfold increase in S-allyl cysteine or SAC that greatly stimulates the immune system and cardiovascular health. The colour of the garlic becomes black due to fermentation and the black colour is probably derived from anthocyanins, which is the reason for the elevated levels of the polyphenols.

In plants such as ginseng and jiaogulan, the active substances are saponins. Saponins are water-soluble molecules that are a kind of tonic for cells. A rejuvenating cure! In older vegetables we ate, there were a lot of saponins. However, because they taste bitter, we expelled them from our food by selection. Saponins can’t just be ingested. The molecules are too big for that. Fermentation reduces the molecules and makes them absorbable. In general, our intestinal flora is no longer able to control this fermentation. Hence the importance of controlled pre-fermentation!

Turmeric contains the phenolic antioxidant curcumin. However, due to its poor water solubility and/or poor stability, there is minimal absorption of curcumin in the intestine. A fermented turmeric drink by lactic acid bacteria resulted in a substantial increase in antioxidant activity indicating increased bioavailability of the curcuminoids.

There are also the large group of fibres. Fibres in our diet are essential for the intestinal flora. The bacteria use them as a source of energy, but they also make short-chain fatty acids (SCFAs) which are a source of energy for the ever-renewing epithelial cells of the colon. This in turn is important for the immune system that keeps the flora in the intestine in balance.

In a disturbed intestinal flora, the capacity to digest fibres is greatly reduced. However, if the bacteria get fibres that have been fermented (cut into small pieces), they will start again. These fibres are called microfibres.  The useful bacteria now produce extra digestive enzymes and displace the harmful microorganisms that are also present in our intestinal flora.

Finally, fermentation can also eliminate “anti-nutrients” such as phytic acid, a compound found in cereal grains that prevents the absorption of minerals, as well as lectins that adversely affect digestion.

The production of kimchi even showed that pesticides could be broken down during the fermentation process.


Fermentation of food and medicinal plants ensures that both primary and secondary plant substances are made more bioavailable to the human organism so that there is a strongly increased activity. So, it makes absolute sense to ferment plants in order to allow all people to enjoy the power of plants, including people with a dysbiotic intestine or a generally weakened organism.


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